1<?xml version="1.0" encoding="ISO-8859-1"?> 2<?xml-stylesheet type="text/xsl" href="jvmti.xsl"?> 3<!-- 4 Copyright (c) 2002, 2017, Oracle and/or its affiliates. All rights reserved. 5 DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 6 7 This code is free software; you can redistribute it and/or modify it 8 under the terms of the GNU General Public License version 2 only, as 9 published by the Free Software Foundation. 10 11 This code is distributed in the hope that it will be useful, but WITHOUT 12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 version 2 for more details (a copy is included in the LICENSE file that 15 accompanied this code). 16 17 You should have received a copy of the GNU General Public License version 18 2 along with this work; if not, write to the Free Software Foundation, 19 Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 21 Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 or visit www.oracle.com if you need additional information or have any 23 questions. 24--> 25 26<!DOCTYPE specification [ 27 <!ELEMENT specification (title, intro*, functionsection, errorsection, 28 eventsection, datasection, issuessection, changehistory)> 29 <!ATTLIST specification label CDATA #REQUIRED 30 majorversion CDATA #REQUIRED 31 minorversion CDATA #REQUIRED 32 microversion CDATA #REQUIRED> 33 34 <!ELEMENT title (#PCDATA|jvmti|tm)*> 35 <!ATTLIST title subtitle CDATA #REQUIRED> 36 37 <!ELEMENT intro ANY> 38 <!ATTLIST intro id CDATA #IMPLIED 39 label CDATA ""> 40 41 <!ELEMENT functionsection (intro*, category*)> 42 <!ATTLIST functionsection label CDATA #REQUIRED> 43 44 <!ELEMENT category ((intro|typedef|uniontypedef|capabilitiestypedef)*, 45 (function|callback|elide)*)> 46 <!ATTLIST category id CDATA #REQUIRED 47 label CDATA #REQUIRED> 48 49 <!ELEMENT function (synopsis, typedef*, description?, origin, 50 (capabilities|eventcapabilities), 51 parameters, errors)> 52 <!ATTLIST function id CDATA #REQUIRED 53 num CDATA #REQUIRED 54 phase (onload|onloadOnly|start|live|any) #IMPLIED 55 callbacksafe (safe|unsafe) #IMPLIED 56 impl CDATA #IMPLIED 57 hide CDATA #IMPLIED 58 jkernel (yes|no) #IMPLIED 59 since CDATA "1.0"> 60 61 <!ELEMENT callback ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject| 62 jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void), 63 synopsis, description?, parameters)> 64 <!ATTLIST callback id CDATA #REQUIRED 65 since CDATA "1.0"> 66 67 <!ELEMENT synopsis (#PCDATA|jvmti)*> 68 69 <!ELEMENT typedef (description?, field*)> 70 <!ATTLIST typedef id CDATA #REQUIRED 71 label CDATA #REQUIRED 72 since CDATA "1.0"> 73 74 <!ELEMENT uniontypedef (description?, field*)> 75 <!ATTLIST uniontypedef id CDATA #REQUIRED 76 label CDATA #REQUIRED 77 since CDATA "1.0"> 78 79 <!ELEMENT field ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject| 80 jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void|allocfieldbuf|inptr|inbuf|outbuf|vmbuf|ptrtype|struct), 81 description)> 82 <!ATTLIST field id CDATA #REQUIRED> 83 84 <!ELEMENT capabilitiestypedef (description?, capabilityfield*)> 85 <!ATTLIST capabilitiestypedef id CDATA #REQUIRED 86 label CDATA #REQUIRED> 87 88 <!ELEMENT capabilityfield (description)> 89 <!ATTLIST capabilityfield id CDATA #REQUIRED 90 disp1 CDATA "" 91 disp2 CDATA "" 92 since CDATA "1.0"> 93 94 <!ELEMENT description ANY> 95 96 <!ELEMENT capabilities (required*, capability*)> 97 98 <!ELEMENT eventcapabilities EMPTY> 99 100 <!ELEMENT required ANY> 101 <!ATTLIST required id CDATA #REQUIRED> 102 103 <!ELEMENT capability ANY> 104 <!ATTLIST capability id CDATA #REQUIRED> 105 106 <!ELEMENT parameters (param*)> 107 108 <!ELEMENT param ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject| 109 jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void|varargs|struct|ptrtype| 110 outptr|allocbuf|allocallocbuf|inptr|inbuf|outbuf|vmbuf|agentbuf), 111 description)> 112 <!ATTLIST param id CDATA #REQUIRED> 113 114 <!ELEMENT jmethodID EMPTY> 115 <!ATTLIST jmethodID class CDATA #IMPLIED 116 native CDATA #IMPLIED> 117 118 <!ELEMENT jfieldID EMPTY> 119 <!ATTLIST jfieldID class CDATA #IMPLIED> 120 121 <!ELEMENT jclass EMPTY> 122 <!ATTLIST jclass method CDATA #IMPLIED 123 field CDATA #IMPLIED> 124 125 <!ELEMENT jframeID EMPTY> 126 <!ATTLIST jframeID thread CDATA #IMPLIED> 127 128 <!ELEMENT jrawMonitorID EMPTY> 129 130 <!ELEMENT jthread EMPTY> 131 <!ATTLIST jthread started CDATA #IMPLIED 132 null CDATA #IMPLIED 133 frame CDATA #IMPLIED 134 impl CDATA #IMPLIED> 135 136 <!ELEMENT varargs EMPTY> 137 138 <!ELEMENT jthreadGroup EMPTY> 139 <!ELEMENT jobject EMPTY> 140 <!ELEMENT jvalue EMPTY> 141 <!ELEMENT jchar EMPTY> 142 <!ELEMENT jint EMPTY> 143 <!ATTLIST jint min CDATA #IMPLIED> 144 <!ELEMENT jlong EMPTY> 145 <!ELEMENT jfloat EMPTY> 146 <!ELEMENT jdouble EMPTY> 147 <!ELEMENT jlocation EMPTY> 148 <!ELEMENT jboolean EMPTY> 149 <!ELEMENT char EMPTY> 150 <!ELEMENT uchar EMPTY> 151 <!ELEMENT size_t EMPTY> 152 <!ELEMENT void EMPTY> 153 <!ELEMENT enum (#PCDATA)*> 154 <!ELEMENT struct (#PCDATA)*> 155 156 <!ELEMENT nullok ANY> 157 158 <!ELEMENT ptrtype ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread| 159 jthreadGroup|jobject|jvalue), nullok?)> 160 161 <!ELEMENT outptr ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread| 162 jthreadGroup|jobject|jvalue|enum|jchar|jint|jlong|jfloat|jdouble| 163 jlocation|jboolean|char|uchar|size_t|void), nullok?)> 164 165 <!ELEMENT allocbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread| 166 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble| 167 jlocation|jboolean|char|uchar|size_t|void), nullok?)> 168 <!ATTLIST allocbuf incount CDATA #IMPLIED 169 outcount CDATA #IMPLIED> 170 171 <!ELEMENT allocallocbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread| 172 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble| 173 jlocation|jboolean|char|uchar|size_t|void), nullok?)> 174 <!ATTLIST allocallocbuf incount CDATA #IMPLIED 175 outcount CDATA #IMPLIED> 176 177 <!ELEMENT inptr (struct, nullok?)> 178 179 <!ELEMENT inbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread| 180 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble| 181 jlocation|jboolean|char|uchar|size_t|void), nullok?)> 182 <!ATTLIST inbuf incount CDATA #IMPLIED> 183 184 <!ELEMENT outbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread| 185 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble| 186 jlocation|jboolean|char|uchar|size_t|void|outbuf), nullok?)> 187 <!ATTLIST outbuf incount CDATA #IMPLIED 188 outcount CDATA #IMPLIED> 189 190 <!ELEMENT vmbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread| 191 jthreadGroup|jobject|jvalue|enum|jchar|jint|jlong|jfloat|jdouble| 192 jlocation|jboolean|char|uchar|size_t|void), nullok?)> 193 <!ATTLIST vmbuf incount CDATA #IMPLIED 194 outcount CDATA #IMPLIED> 195 196 <!ELEMENT agentbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread| 197 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble| 198 jlocation|jboolean|char|uchar|size_t|void), nullok?)> 199 <!ATTLIST agentbuf incount CDATA #IMPLIED 200 outcount CDATA #IMPLIED> 201 202 <!ELEMENT allocfieldbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread| 203 jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble| 204 jlocation|jboolean|char|uchar|size_t|void))> 205 <!ATTLIST allocfieldbuf outcount CDATA #IMPLIED> 206 207 <!ELEMENT errors (error*)> 208 209 <!ELEMENT error ANY> 210 <!ATTLIST error id CDATA #REQUIRED> 211 212 <!ELEMENT errorsection (intro*, errorcategory*)> 213 <!ATTLIST errorsection label CDATA #REQUIRED> 214 215 <!ELEMENT errorcategory (intro*, errorid*)> 216 <!ATTLIST errorcategory id CDATA #REQUIRED 217 label CDATA #REQUIRED> 218 219 <!ELEMENT errorid ANY> 220 <!ATTLIST errorid id CDATA #REQUIRED 221 num CDATA #REQUIRED> 222 223 <!ELEMENT datasection (intro*, basetypes*)> 224 225 <!ELEMENT basetypes (intro*, basetype*)> 226 <!ATTLIST basetypes id CDATA #REQUIRED 227 label CDATA #REQUIRED> 228 229 <!ELEMENT basetype (definition?,description)> 230 <!ATTLIST basetype id CDATA #REQUIRED> 231 232 <!ELEMENT definition (#PCDATA|jvmti)*> 233 234 <!ELEMENT eventsection (intro*, (event|elide)*)> 235 <!ATTLIST eventsection label CDATA #REQUIRED> 236 237 <!ELEMENT event (description, origin, typedef*, capabilities, parameters)> 238 <!ATTLIST event id CDATA #REQUIRED 239 label CDATA #REQUIRED 240 const CDATA #REQUIRED 241 num CDATA #REQUIRED 242 phase (onload|start|live|any) #IMPLIED 243 filtered (thread|global) #IMPLIED 244 since CDATA "1.0"> 245 246 <!ELEMENT issuessection (intro*)> 247 <!ATTLIST issuessection label CDATA #REQUIRED> 248 249 <!ELEMENT changehistory (intro*, change*)> 250 <!ATTLIST changehistory update CDATA #REQUIRED 251 id CDATA #REQUIRED> 252 253 <!ELEMENT change ANY> 254 <!ATTLIST change date CDATA #REQUIRED 255 version CDATA #IMPLIED> 256 257 <!ELEMENT functionlink (#PCDATA|jvmti|code|i|b)*> 258 <!ATTLIST functionlink id CDATA #REQUIRED> 259 260 <!ELEMENT datalink (#PCDATA|jvmti|code|i|b)*> 261 <!ATTLIST datalink id CDATA #REQUIRED> 262 263 <!ELEMENT typelink (#PCDATA|jvmti|code|i|b)*> 264 <!ATTLIST typelink id CDATA #REQUIRED> 265 266 <!ELEMENT fieldlink (#PCDATA|jvmti|code|i|b)*> 267 <!ATTLIST fieldlink id CDATA #REQUIRED 268 struct CDATA #REQUIRED> 269 270 <!ELEMENT paramlink (#PCDATA|jvmti|code|i|b)*> 271 <!ATTLIST paramlink id CDATA #REQUIRED> 272 273 <!ELEMENT eventlink (#PCDATA|jvmti|code|i|b)*> 274 <!ATTLIST eventlink id CDATA #REQUIRED> 275 276 <!ELEMENT errorlink (#PCDATA|jvmti|code|i|b|tm)*> 277 <!ATTLIST errorlink id CDATA #REQUIRED> 278 279 <!ELEMENT externallink (#PCDATA|jvmti|code|i|b|tm)*> 280 <!ATTLIST externallink id CDATA #REQUIRED> 281 282 <!ELEMENT vmspec EMPTY> 283 <!ATTLIST vmspec chapter CDATA #IMPLIED> 284 285 <!ELEMENT internallink (#PCDATA|jvmti|code|i|b)*> 286 <!ATTLIST internallink id CDATA #REQUIRED> 287 288 <!ELEMENT functionphaselist EMPTY> 289 <!ATTLIST functionphaselist phase (onload|onloadOnly|start|live|any) #REQUIRED> 290 291 <!ELEMENT eventphaselist EMPTY> 292 <!ATTLIST eventphaselist phase (onload|start|live|any) #REQUIRED> 293 294 <!ELEMENT issue ANY> 295 296 <!ELEMENT rationale ANY> 297 298 <!ELEMENT todo ANY> 299 300 <!ELEMENT origin (#PCDATA)*> 301 302 <!ELEMENT elide (intro|function|callback|event)*> 303 <!ATTLIST elide why CDATA #IMPLIED> 304 305 <!ELEMENT constants (constant*)> 306 <!ATTLIST constants id CDATA #REQUIRED 307 label CDATA #REQUIRED 308 kind (enum|bits|const) #REQUIRED 309 since CDATA "1.0"> 310 311 <!ELEMENT constant ANY> 312 <!ATTLIST constant id CDATA #REQUIRED 313 num CDATA #REQUIRED> 314 315 <!ELEMENT tm (#PCDATA)> 316 317 <!ELEMENT i (#PCDATA|jvmti|tm)*> 318 319 <!ELEMENT b (#PCDATA|jvmti|code)*> 320 321 <!ELEMENT code (#PCDATA|space)*> 322 323 <!ELEMENT pre ANY> 324 325 <!ELEMENT space EMPTY> 326 327 <!ELEMENT jvmti EMPTY> 328 329 <!ELEMENT example (#PCDATA|i)*> 330 331 <!ELEMENT br EMPTY> 332 333 <!ELEMENT p EMPTY> 334 335 <!ELEMENT dl (dt|dd)+> 336 337 <!ELEMENT dd ANY> 338 339 <!ELEMENT dt (#PCDATA|jvmti|code|i|b)*> 340 341 <!ELEMENT table (tr)+> 342 343 <!ELEMENT tr (td|th)*> 344 345 <!ELEMENT td ANY> 346 <!ATTLIST td align (left|right|center) "center"> 347 348 <!ELEMENT th ANY> 349 <!ATTLIST th align (left|right|center) "center"> 350 351 <!ELEMENT ul (li)+> 352 <!ATTLIST ul type (disc|circle|square) "disc"> 353 354 <!ELEMENT li ANY> 355 ]> 356 357<specification label="JVM(TM) Tool Interface" 358 majorversion="9" 359 minorversion="0" 360 microversion="0"> 361 <title subtitle="Version"> 362 <tm>JVM</tm> Tool Interface 363 </title> 364 365 <intro id="whatIs" label="What is the JVM Tool Interface?"> 366 The <tm>JVM</tm> Tool Interface (<jvmti/>) 367 is a programming interface used by development and monitoring tools. 368 It provides both a way to inspect the state and 369 to control the execution of applications running in the 370 <tm>Java</tm> virtual machine (VM). 371 <p/> 372 <jvmti/> is intended to provide a VM interface for the full breadth of tools 373 that need access to VM state, including but not limited to: profiling, 374 debugging, monitoring, thread analysis, and coverage analysis tools. 375 <p/> 376 <jvmti/> may not be available in all implementations of the <tm>Java</tm> virtual 377 machine. 378 <p/> 379 <jvmti/> is a two-way interface. 380 A client of <jvmti/>, hereafter called an <i>agent</i>, 381 can be notified of 382 interesting occurrences through <internallink id="EventSection">events</internallink>. 383 <jvmti/> 384 can query and control the application through many 385 <internallink id="FunctionSection">functions</internallink>, 386 either in response to events or 387 independent of them. 388 <p/> 389 Agents run in the same process with and communicate directly with 390 the virtual machine executing 391 the application being examined. This communication is 392 through a native interface (<jvmti/>). The native in-process interface allows 393 maximal control with minimal intrusion on the part of a tool. 394 Typically, agents are relatively compact. They can be controlled 395 by a separate process which implements the bulk of a tool's 396 function without interfering with the target application's normal execution. 397 </intro> 398 399 <intro id="architecture" label="Architecture"> 400 Tools can be written directly to <jvmti/> or indirectly 401 through higher level interfaces. 402 The Java Platform Debugger Architecture includes <jvmti/>, but also 403 contains higher-level, out-of-process debugger interfaces. The higher-level 404 interfaces are more appropriate than <jvmti/> for many tools. 405 For more information on the Java Platform Debugger Architecture, 406 see the 407 <externallink id="docs/technotes/guides/jpda/architecture.html">Java 408 Platform Debugger Architecture website</externallink>. 409 </intro> 410 411 <intro id="writingAgents" label="Writing Agents"> 412 Agents can be written in any native language that supports C 413 language calling conventions and C or C++ 414 definitions. 415 <p/> 416 The function, event, data type, and constant definitions needed for 417 using <jvmti/> are defined in the include file <code>jvmti.h</code>. 418 To use these definitions add the <tm>J2SE</tm> include directory 419 to your include path and add 420 <example> 421#include <jvmti.h> 422 </example> 423 to your source code. 424 </intro> 425 426 <intro id="deployingAgents" label="Deploying Agents"> 427 An agent is deployed in a platform specific manner but is typically the 428 platform equivalent of a dynamic library. On the <tm>Windows</tm> operating 429 system, for example, an agent library is a "Dynamic Linked Library" (DLL). 430 On the <tm>Solaris</tm> Operating Environment, an agent library is a shared 431 object (<code>.so</code> file). 432 <p/> 433 434 An agent may be started at VM startup by specifying the agent library 435 name using a <internallink id="starting">command line option</internallink>. 436 Some implementations may support a mechanism to <internallink id="onattach"> 437 start agents</internallink> in the live <functionlink id="GetPhase">phase</functionlink>. 438 The details of how this is initiated are implementation specific. 439 </intro> 440 441 <intro id="entry point" label="Statically Linked Agents (since version 1.2.3)"> 442 443 A native JVMTI Agent may be <i>statically linked</i> with the VM. 444 The manner in which the library and VM image are combined is 445 implementation-dependent. 446 An agent L whose image has been combined with the VM is defined as 447 <i>statically linked</i> if and only if the agent exports a function 448 called Agent_OnLoad_L. 449<p/> 450 If a <i>statically linked</i> agent L exports a function called 451 Agent_OnLoad_L and a function called Agent_OnLoad, the Agent_OnLoad 452 function will be ignored. 453 If an agent L is <i>statically linked</i>, an Agent_OnLoad_L 454 function will be invoked with the same arguments and expected return 455 value as specified for the Agent_OnLoad function. 456 An agent L that is <i>statically linked</i> will prohibit an agent of 457 the same name from being loaded dynamically. 458<p/> 459 The VM will invoke the Agent_OnUnload_L function of the agent, if such 460 a function is exported, at the same point during VM execution as it would 461 have called the dynamic entry point Agent_OnUnLoad. A statically loaded 462 agent cannot be unloaded. The Agent_OnUnload_L function will still be 463 called to do any other agent shutdown related tasks. 464 If a <i>statically linked</i> agent L exports a function called 465 Agent_OnUnLoad_L and a function called Agent_OnUnLoad, the Agent_OnUnLoad 466 function will be ignored. 467<p/> 468 If an agent L is <i>statically linked</i>, an Agent_OnAttach_L function 469 will be invoked with the same arguments and expected return value as 470 specified for the Agent_OnAttach function. 471 If a <i>statically linked</i> agent L exports a function called 472 Agent_OnAttach_L and a function called Agent_OnAttach, the Agent_OnAttach 473 function will be ignored. 474</intro> 475 476 <intro id="starting" label="Agent Command Line Options"> 477 The term "command-line option" is used below to 478 mean options supplied in the <code>JavaVMInitArgs</code> argument 479 to the <code>JNI_CreateJavaVM</code> function of the JNI 480 Invocation API. 481 <p/> 482 One of the two following 483 command-line options is used on VM startup to 484 properly load and run agents. 485 These arguments identify the library containing 486 the agent as well as an options 487 string to be passed in at startup. 488 <dl> 489 <dt><code>-agentlib:</code><i><agent-lib-name></i><code>=</code><i><options></i></dt> 490 <dd> 491 The name following <code>-agentlib:</code> is the name of the 492 library to load. Lookup of the library, both its full name and location, 493 proceeds in a platform-specific manner. 494 Typically, the <i><agent-lib-name></i> is expanded to an 495 operating system specific file name. 496 The <i><options></i> will be passed to the agent on start-up. 497 For example, if the option 498 <code>-agentlib:foo=opt1,opt2</code> is specified, the VM will attempt to 499 load the shared library <code>foo.dll</code> from the system <code>PATH</code> 500 under <tm>Windows</tm> or <code>libfoo.so</code> from the 501 <code>LD_LIBRARY_PATH</code> under the <tm>Solaris</tm> operating 502 environment. 503 If the agent library is statically linked into the executable 504 then no actual loading takes place. 505 <p/> 506 </dd> 507 <dt><code>-agentpath:</code><i><path-to-agent></i><code>=</code><i><options></i></dt> 508 <dd> 509 The path following <code>-agentpath:</code> is the absolute path from which 510 to load the library. 511 No library name expansion will occur. 512 The <i><options></i> will be passed to the agent on start-up. 513 For example, if the option 514 <code>-agentpath:c:\myLibs\foo.dll=opt1,opt2</code> is specified, the VM will attempt to 515 load the shared library <code>c:\myLibs\foo.dll</code>. If the agent 516 library is statically linked into the executable 517 then no actual loading takes place. 518 <p/> 519 </dd> 520 </dl> 521 For a dynamic shared library agent, the start-up routine 522 <internallink id="onload"><code>Agent_OnLoad</code></internallink> 523 in the library will be invoked. If the agent library is statically linked 524 into the executable then the system will attempt to invoke the 525 <code>Agent_OnLoad_<agent-lib-name></code> entry point where 526 <agent-lib-name> is the basename of the 527 agent. In the above example <code>-agentpath:c:\myLibs\foo.dll=opt1,opt2</code>, 528 the system will attempt to find and call the <code>Agent_OnLoad_foo</code> start-up routine. 529 <p/> 530 Libraries loaded with <code>-agentlib:</code> or <code>-agentpath:</code> 531 will be searched for JNI native method implementations to facilitate the 532 use of Java programming language code in tools, as is needed for 533 <internallink id="bci">bytecode instrumentation</internallink>. 534 <p/> 535 The agent libraries will be searched after all other libraries have been 536 searched (agents wishing to override or intercept the native method 537 implementations of non-agent methods can use the 538 <eventlink id="NativeMethodBind">NativeMethodBind event</eventlink>). 539 <p/> 540 These switches do the above and nothing more - they do not change the 541 state of the VM or <jvmti/>. No command line options are needed 542 to enable <jvmti/> 543 or aspects of <jvmti/>, this is handled programmatically 544 by the use of 545 <internallink id="capability">capabilities</internallink>. 546 </intro> 547 548 <intro id="startup" label="Agent Start-Up"> 549 The VM starts each agent by invoking a start-up function. 550 If the agent is started in the <code>OnLoad</code> 551 <functionlink id="GetPhase">phase</functionlink> the function 552 <internallink id="onload"><code>Agent_OnLoad</code></internallink> 553 or <internallink id="onload"><code>Agent_OnLoad_L</code></internallink> 554 for statically linked agents will be invoked. 555 If the agent is started in the live 556 <functionlink id="GetPhase">phase</functionlink> the function 557 <internallink id="onattach"><code>Agent_OnAttach</code></internallink> 558 or <internallink id="onattach"><code>Agent_OnAttach_L</code></internallink> 559 for statically linked agents will be invoked. 560 Exactly one call to a start-up function is made per agent. 561 </intro> 562 563 <intro id="onload" label="Agent Start-Up (OnLoad phase)"> 564 If an agent is started during the <code>OnLoad</code> phase then its 565 agent library must export a start-up function with the following prototype: 566 <example> 567JNIEXPORT jint JNICALL 568Agent_OnLoad(JavaVM *vm, char *options, void *reserved)</example> 569 Or for a statically linked agent named 'L': 570 <example> 571JNIEXPORT jint JNICALL 572Agent_OnLoad_L(JavaVM *vm, char *options, void *reserved)</example> 573 574 The VM will start the agent by calling this function. 575 It will be called early enough in VM initialization that: 576 <ul> 577 <li><functionlink id="SetSystemProperty">system properties</functionlink> 578 may be set before they have been used in the start-up of the VM</li> 579 <li>the full set of 580 <internallink id="capability">capabilities</internallink> 581 is still available (note that capabilities that configure the VM 582 may only be available at this time--see the 583 <internallink id="capability">Capability function section</internallink>)</li> 584 <li>no bytecodes have executed</li> 585 <li>no classes have been loaded</li> 586 <li>no objects have been created</li> 587 </ul> 588 <p/> 589 The VM will call the <code>Agent_OnLoad</code> or 590 <code>Agent_OnLoad_<agent-lib-name></code> function with 591 <i><options></i> as the second argument - 592 that is, using the command-line option examples, 593 <code>"opt1,opt2"</code> will be passed to the <code>char *options</code> 594 argument of <code>Agent_OnLoad</code>. 595 The <code>options</code> argument is encoded as a 596 <internallink id="mUTF">modified UTF-8</internallink> string. 597 If <i>=<options></i> is not specified, 598 a zero length string is passed to <code>options</code>. 599 The lifespan of the <code>options</code> string is the 600 <code>Agent_OnLoad</code> or <code>Agent_OnLoad_<agent-lib-name></code> 601 call. If needed beyond this time the string or parts of the string must 602 be copied. 603 The period between when <code>Agent_OnLoad</code> is called and when it 604 returns is called the <i>OnLoad phase</i>. 605 Since the VM is not initialized during the OnLoad 606 <functionlink id="GetPhase">phase</functionlink>, 607 the set of allowed operations 608 inside <code>Agent_OnLoad</code> is restricted (see the function descriptions for the 609 functionality available at this time). 610 The agent can safely process the options and set 611 event callbacks with <functionlink id="SetEventCallbacks"></functionlink>. Once 612 the VM initialization event is received 613 (that is, the <eventlink id="VMInit">VMInit</eventlink> 614 callback is invoked), the agent 615 can complete its initialization. 616 <rationale> 617 Early startup is required so that agents can set the desired capabilities, 618 many of which must be set before the VM is initialized. 619 In JVMDI, the -Xdebug command-line option provided 620 very coarse-grain control of capabilities. 621 JVMPI implementations use various tricks to provide a single "JVMPI on" switch. 622 No reasonable command-line 623 option could provide the fine-grain of control required to balance needed capabilities vs 624 performance impact. 625 Early startup is also needed so that agents can control the execution 626 environment - modifying the file system and system properties to install 627 their functionality. 628 </rationale> 629 <p/> 630 The return value from <code>Agent_OnLoad</code> or 631 <code>Agent_OnLoad_<agent-lib-name></code> is used to indicate an error. 632 Any value other than zero indicates an error and causes termination of the VM. 633 </intro> 634 635 <intro id="onattach" label="Agent Start-Up (Live phase)"> 636 A VM may support a mechanism that allows agents to be started in the VM during the live 637 <functionlink id="GetPhase">phase</functionlink>. The details of how this is supported, 638 are implementation specific. For example, a tool may use some platform specific mechanism, 639 or implementation specific API, to attach to the running VM, and request it start a given 640 agent. 641 <p/> 642 If an agent is started during the live phase then its agent library 643 must export a start-up function 644 with the following prototype: 645 <example> 646JNIEXPORT jint JNICALL 647Agent_OnAttach(JavaVM* vm, char *options, void *reserved)</example> 648Or for a statically linked agent named 'L': 649 <example> 650JNIEXPORT jint JNICALL 651Agent_OnAttach_L(JavaVM* vm, char *options, void *reserved)</example> 652 653 <p/> 654 The VM will start the agent by calling this function. 655 It will be called in the context of a thread 656 that is attached to the VM. The first argument <i><vm></i> is the Java VM. 657 The <i><options></i> argument is the startup options provided to the agent. 658 <i><options></i> is encoded as a <internallink id="mUTF">modified UTF-8 659 </internallink> string. 660 If startup options were not provided, a zero length string is passed to 661 <code>options</code>. The lifespan of the <code>options</code> string is the 662 <code>Agent_OnAttach</code> or <code>Agent_OnAttach_<agent-lib-name></code> call. 663 If needed beyond this time the string or parts of the string must be copied. 664 <p/> 665 Note that some <internallink id="capability">capabilities</internallink> 666 may not be available in the live phase. 667 <p/> 668 The <code>Agent_OnAttach</code> or <code>Agent_OnAttach_<agent-lib-name 669 ></code> function initializes the agent and returns a value 670 to the VM to indicate if an error occurred. Any value other than zero indicates an error. 671 An error does not cause the VM to terminate. Instead the VM ignores the error, or takes 672 some implementation specific action -- for example it might print an error to standard error, 673 or record the error in a system log. 674 </intro> 675 676 <intro id="onunload" label="Agent Shutdown"> 677 The library may optionally export a 678 shutdown function with the following prototype: 679 <example> 680JNIEXPORT void JNICALL 681Agent_OnUnload(JavaVM *vm)</example> 682 Or for a statically linked agent named 'L': 683 <example> 684JNIEXPORT void JNICALL 685Agent_OnUnload_L(JavaVM *vm)</example> 686 687 This function will be called by the VM when the library is about to be unloaded. 688 The library will be unloaded (unless it is statically linked into the 689 executable) and this function will be called if some platform specific 690 mechanism causes the unload (an unload mechanism is not specified in this document) 691 or the library is (in effect) unloaded by the termination of the VM whether through 692 normal termination or VM failure, including start-up failure. 693 Uncontrolled shutdown is, of couse, an exception to this rule. 694 Note the distinction between this function and the 695 <eventlink id="VMDeath">VM Death event</eventlink>: for the VM Death event 696 to be sent, the VM must have run at least to the point of initialization and a valid 697 <jvmti/> environment must exist which has set a callback for VMDeath 698 and enabled the event. 699 None of these are required for <code>Agent_OnUnload</code> or 700 <code>Agent_OnUnload_<agent-lib-name></code> and this function 701 is also called if the library is unloaded for other reasons. 702 In the case that a VM Death event is sent, it will be sent before this 703 function is called (assuming this function is called due to VM termination). 704 This function can be used to clean-up resources allocated by the agent. 705 </intro> 706 707 <intro id="tooloptions" label="JAVA_TOOL_OPTIONS"> 708 Since the command-line cannot always be accessed or modified, for example in embedded VMs 709 or simply VMs launched deep within scripts, a <code>JAVA_TOOL_OPTIONS</code> variable is 710 provided so that agents may be launched in these cases. 711 <p/> 712 Platforms which support environment variables or other named strings, may support the 713 <code>JAVA_TOOL_OPTIONS</code> variable. This variable will be broken into options at white-space 714 boundaries. White-space characters include space, tab, carriage-return, new-line, 715 vertical-tab, and form-feed. Sequences of white-space characters are considered 716 equivalent to a single white-space character. No white-space is included in the options 717 unless quoted. Quoting is as follows: 718 <ul> 719 <li>All characters enclosed between a pair of single quote marks (''), except a single 720 quote, are quoted.</li> 721 <li>Double quote characters have no special meaning inside a pair of single quote marks.</li> 722 <li>All characters enclosed between a pair of double quote marks (""), except a double 723 quote, are quoted.</li> 724 <li>Single quote characters have no special meaning inside a pair of double quote marks.</li> 725 <li>A quoted part can start or end anywhere in the variable.</li> 726 <li>White-space characters have no special meaning when quoted -- they are included in 727 the option like any other character and do not mark white-space boundaries.</li> 728 <li>The pair of quote marks is not included in the option.</li> 729 </ul> 730 <code>JNI_CreateJavaVM</code> (in the JNI Invocation API) will prepend these options to the options supplied 731 in its <code>JavaVMInitArgs</code> argument. Platforms may disable this feature in cases where security is 732 a concern; for example, the Reference Implementation disables this feature on Unix systems when 733 the effective user or group ID differs from the real ID. 734 This feature is intended to support the initialization of tools -- specifically including the 735 launching of native or Java programming language agents. Multiple tools may wish to use this 736 feature, so the variable should not be overwritten, instead, options should be appended to 737 the variable. Note that since the variable is processed at the time of the JNI Invocation 738 API create VM call, options processed by a launcher (e.g., VM selection options) will not be handled. 739 </intro> 740 741 <intro id="environments" label="Environments"> 742 The <jvmti/> specification supports the use of multiple simultaneous 743 <jvmti/> agents. 744 Each agent has its own <jvmti/> environment. 745 That is, the <jvmti/> state is 746 separate for each agent - changes to one environment do not affect the 747 others. The state of a <jvmti/> 748 environment includes: 749 <ul> 750 <li><functionlink id="SetEventCallbacks">the event callbacks</functionlink></li> 751 <li><functionlink id="SetEventNotificationMode">the set of events which are enabled</functionlink></li> 752 <li><internallink id="capability">the capabilities</internallink></li> 753 <li><internallink id="memory">the memory allocation/deallocation hooks</internallink></li> 754 </ul> 755 Although their <jvmti/> state 756 is separate, agents inspect and modify the shared state 757 of the VM, they also share the native environment in which they execute. 758 As such, an agent can perturb the results of other agents or cause them 759 to fail. It is the responsibility of the agent writer to specify the level 760 of compatibility with other agents. <jvmti/> implementations are not capable 761 of preventing destructive interactions between agents. Techniques to reduce 762 the likelihood of these occurrences are beyond the scope of this document. 763 <p/> 764 An agent creates a <jvmti/> environment 765 by passing a <jvmti/> version 766 as the interface ID to the JNI Invocation API function 767 <externallink id="jni/invocation.html#getenv"> 768 <code>GetEnv</code></externallink>. 769 See <internallink id="jvmtiEnvAccess">Accessing <jvmti/> Functions</internallink> 770 for more details on the creation and use of 771 <jvmti/> environments. 772 Typically, <jvmti/> environments are created by calling <code>GetEnv</code> from 773 <internallink id="onload"><code>Agent_OnLoad</code></internallink>. 774 </intro> 775 776 <intro id="bci" label="Bytecode Instrumentation"> 777 This interface does not include some events that one might expect in an interface with 778 profiling support. Some examples include object allocation events and full speed 779 method enter and exit events. The interface instead provides support for 780 <i>bytecode instrumentation</i>, the ability to alter the Java virtual machine 781 bytecode instructions which comprise the target program. Typically, these alterations 782 are to add "events" to the code of a method - for example, to add, at the beginning of a method, 783 a call to <code>MyProfiler.methodEntered()</code>. 784 Since the changes are purely additive, they do not modify application 785 state or behavior. 786 Because the inserted agent code is standard bytecodes, the VM can run at full speed, 787 optimizing not only the target program but also the instrumentation. If the 788 instrumentation does not involve switching from bytecode execution, no expensive 789 state transitions are needed. The result is high performance events. 790 This approach also provides complete control to the agent: instrumentation can be 791 restricted to "interesting" portions of the code (e.g., the end user's code) and 792 can be conditional. Instrumentation can run entirely in Java programming language 793 code or can call into the native agent. Instrumentation can simply maintain 794 counters or can statistically sample events. 795 <p/> 796 Instrumentation can be inserted in one of three ways: 797 <ul> 798 <li> 799 Static Instrumentation: The class file is instrumented before it 800 is loaded into the VM - for example, by creating a duplicate directory of 801 <code>*.class</code> files which have been modified to add the instrumentation. 802 This method is extremely awkward and, in general, an agent cannot know 803 the origin of the class files which will be loaded. 804 </li> 805 <li> 806 Load-Time Instrumentation: When a class file is loaded by the VM, the raw 807 bytes of the class file are sent for instrumentation to the agent. 808 The <eventlink id="ClassFileLoadHook"/> 809 event, triggered by the class load, 810 provides this functionality. This mechanism provides efficient 811 and complete access to one-time instrumentation. 812 </li> 813 <li> 814 Dynamic Instrumentation: A class which is already loaded (and possibly 815 even running) is modified. This optional feature is provided by the 816 <eventlink id="ClassFileLoadHook"/> event, triggered by calling the 817 <functionlink id="RetransformClasses"/> function. 818 Classes can be modified multiple times and can be returned to their 819 original state. 820 The mechanism allows instrumentation which changes during the 821 course of execution. 822 </li> 823 </ul> 824 <p/> 825 The class modification functionality provided in this interface 826 is intended to provide a mechanism for instrumentation 827 (the <eventlink id="ClassFileLoadHook"/> event 828 and the <functionlink id="RetransformClasses"/> function) 829 and, during development, for fix-and-continue debugging 830 (the <functionlink id="RedefineClasses"/> function). 831 <p/> 832 Care must be taken to avoid perturbing dependencies, especially when 833 instrumenting core classes. For example, an approach to getting notification 834 of every object allocation is to instrument the constructor on 835 <code>Object</code>. Assuming that the constructor is initially 836 empty, the constructor could be changed to: 837 <example> 838 public Object() { 839 MyProfiler.allocationTracker(this); 840 } 841 </example> 842 However, if this change was made using the 843 <eventlink id="ClassFileLoadHook"/> 844 event then this might impact a typical VM as follows: 845 the first created object will call the constructor causing a class load of 846 <code>MyProfiler</code>; which will then cause 847 object creation, and since <code>MyProfiler</code> isn't loaded yet, 848 infinite recursion; resulting in a stack overflow. A refinement of this 849 would be to delay invoking the tracking method until a safe time. For 850 example, <code>trackAllocations</code> could be set in the 851 handler for the <code>VMInit</code> event. 852 <example> 853 static boolean trackAllocations = false; 854 855 public Object() { 856 if (trackAllocations) { 857 MyProfiler.allocationTracker(this); 858 } 859 } 860 </example> 861 <p/> 862 The <functionlink id="SetNativeMethodPrefix"/> allows native methods 863 to be instrumented by the use of wrapper methods. 864 </intro> 865 866<intro id="bcimodules" label="Bytecode Instrumentation of code in modules"> 867 Agents can use the functions <functionlink id="AddModuleReads"/>, 868 <functionlink id="AddModuleExports"/>, <functionlink id="AddModuleOpens"/>, 869 <functionlink id="AddModuleUses"/> and <functionlink id="AddModuleProvides"/> 870 to update a module to expand the set of modules that it reads, the set of 871 packages that it exports or opens to other modules, or the services that it 872 uses and provides. 873 <p/> 874 As an aid to agents that deploy supporting classes on the search path of 875 the bootstrap class loader, or the search path of the class loader that 876 loads the main class, the Java virtual machine arranges for the module 877 of classes transformed by the <eventlink id="ClassFileLoadHook"/> event to 878 read the unnamed module of both class loaders. 879</intro> 880 881 <intro id="mUTF" label="Modified UTF-8 String Encoding"> 882 <jvmti/> uses modified UTF-8 to encode character strings. 883 This is the same encoding used by JNI. 884 Modified UTF-8 differs 885 from standard UTF-8 in the representation of supplementary characters 886 and of the null character. See the 887 <externallink id="jni/types.html#modified-utf-8-strings"> 888 Modified UTF-8 Strings</externallink> 889 section of the JNI specification for details. 890 </intro> 891 892 <intro id="context" label="Specification Context"> 893 Since this interface provides access to the state of applications running in the 894 Java virtual machine; 895 terminology refers to the Java platform and not the native 896 platform (unless stated otherwise). For example: 897 <ul> 898 <li>"thread" means Java programming language thread.</li> 899 <li>"stack frame" means Java virtual machine stack frame.</li> 900 <li>"class" means Java programming language class.</li> 901 <li>"heap" means Java virtual machine heap.</li> 902 <li>"monitor" means Java programming language object monitor.</li> 903 </ul> 904 <p/> 905 Sun, Sun Microsystems, the Sun logo, Java, and JVM 906 are trademarks or registered trademarks of Oracle 907 and/or its affiliates, in the U.S. and other countries. 908 </intro> 909 910 911<functionsection label="Functions"> 912 <intro id="jvmtiEnvAccess" label="Accessing Functions"> 913 Native code accesses <jvmti/> features 914 by calling <jvmti/> functions. 915 Access to <jvmti/> functions is by use of an interface pointer 916 in the same manner as 917 <externallink id="jni/design.html">Java 918 Native Interface (JNI) functions</externallink> are accessed. 919 The <jvmti/> interface pointer is called the 920 <i>environment pointer</i>. 921 <p/> 922 An environment pointer is a pointer to an environment and has 923 the type <code>jvmtiEnv*</code>. 924 An environment has information about its <jvmti/> connection. 925 The first value in the environment is a pointer to the function table. 926 The function table is an array of pointers to <jvmti/> functions. 927 Every function pointer is at a predefined offset inside the 928 array. 929 <p/> 930 When used from the C language: 931 double indirection is used to access the functions; 932 the environment pointer provides context and is the first 933 parameter of each function call; for example: 934 <example> 935jvmtiEnv *jvmti; 936... 937jvmtiError err = (*jvmti)->GetLoadedClasses(jvmti, &class_count, &classes); 938 </example> 939 <p/> 940 When used from the C++ language: 941 functions are accessed as member functions of <code>jvmtiEnv</code>; 942 the environment pointer is not passed to the function call; for example: 943 <example> 944jvmtiEnv *jvmti; 945... 946jvmtiError err = jvmti->GetLoadedClasses(&class_count, &classes); 947 </example> 948 Unless otherwise stated, all examples and declarations in this 949 specification use the C language. 950 <p/> 951 A <jvmti/> environment can be obtained through the JNI Invocation API 952 <code>GetEnv</code> function: 953 <example> 954jvmtiEnv *jvmti; 955... 956(*jvm)->GetEnv(jvm, &jvmti, JVMTI_VERSION_1_0); 957 </example> 958 Each call to <code>GetEnv</code> 959 creates a new <jvmti/> connection and thus 960 a new <jvmti/> environment. 961 The <code>version</code> argument of <code>GetEnv</code> must be 962 a <jvmti/> version. 963 The returned environment may have a different version than the 964 requested version but the returned environment must be compatible. 965 <code>GetEnv</code> will return <code>JNI_EVERSION</code> if a 966 compatible version is not available, if <jvmti/> is not supported or 967 <jvmti/> is not supported in the current VM configuration. 968 Other interfaces may be added for creating <jvmti/> environments 969 in specific contexts. 970 Each environment has its own state (for example, 971 <functionlink id="SetEventNotificationMode">desired events</functionlink>, 972 <functionlink id="SetEventCallbacks">event handling functions</functionlink>, and 973 <functionlink id="AddCapabilities">capabilities</functionlink>). 974 An environment is released with 975 <functionlink id="DisposeEnvironment"></functionlink>. 976 Thus, unlike JNI which has one environment per thread, <jvmti/> environments work 977 across threads and are created dynamically. 978 </intro> 979 980 <intro id="functionReturn" label="Function Return Values"> 981 <jvmti/> functions always return an 982 <internallink id="ErrorSection">error code</internallink> via the 983 <datalink id="jvmtiError"/> function return value. 984 Some functions can return additional 985 values through pointers provided by the calling function. 986 In some cases, <jvmti/> functions allocate memory that your program must 987 explicitly deallocate. This is indicated in the individual <jvmti/> 988 function descriptions. Empty lists, arrays, sequences, etc are 989 returned as <code>NULL</code>. 990 <p/> 991 In the event that the <jvmti/> function encounters 992 an error (any return value other than <code>JVMTI_ERROR_NONE</code>) the values 993 of memory referenced by argument pointers is undefined, but no memory 994 will have been allocated and no global references will have been allocated. 995 If the error occurs because of invalid input, no action will have occurred. 996 </intro> 997 998<intro id="refs" label="Managing JNI Object References"> 999 <jvmti/> functions identify objects with JNI references 1000 (<datalink id="jobject"/> and <datalink id="jclass"/>) 1001 and their derivatives 1002 (<datalink id="jthread"/> and <datalink id="jthreadGroup"/>). 1003 References passed to 1004 <jvmti/> functions can be either global or local, but they must be 1005 strong references. All references returned by <jvmti/> functions are 1006 local references--these local references are created 1007 during the <jvmti/> call. 1008 Local references are a resource that must be managed (see the 1009 <externallink id="jni/functions.html#local-references"> 1010 JNI Documentation</externallink>). 1011 When threads return from native code all local references 1012 are freed. Note that some threads, including typical 1013 agent threads, will never return from native code. 1014 A thread is ensured the ability to create sixteen local 1015 references without the need for any explicit management. 1016 For threads executing a limited number of <jvmti/> calls before 1017 returning from native code 1018 (for example, threads processing events), 1019 it may be determined that no explicit management 1020 is needed. 1021 However, long running agent threads will need explicit 1022 local reference management--usually with the JNI functions 1023 <code>PushLocalFrame</code> and <code>PopLocalFrame</code>. 1024 Conversely, to preserve references beyond the 1025 return from native code, they must be converted to global references. 1026 These rules do not apply to <datalink id="jmethodID"/> and <datalink id="jfieldID"/> 1027 as they are not <datalink id="jobject"/>s. 1028</intro> 1029 1030 <intro id="prereqState" label="Prerequisite State for Calling Functions"> 1031 Unless the function explicitly states that the agent must bring 1032 a thread or the VM to a particular state (for example, suspended), 1033 the <jvmti/> implementation is responsible for bringing the VM to a 1034 safe and consistent state for performing the function. 1035 </intro> 1036 1037 <intro id="functionsExceptions" label="Exceptions and Functions"> 1038 <jvmti/> functions never throw exceptions; error conditions are 1039 communicated via the 1040 <internallink id="functionReturn">function return value</internallink>. 1041 Any existing exception state is preserved across a call to a 1042 <jvmti/> function. 1043 See the 1044 <externallink 1045 id="jni/design.html#java-exceptions" 1046 >Java Exceptions</externallink> 1047 section of the JNI specification for information on handling exceptions. 1048 </intro> 1049 1050 <category id="memory" label="Memory Management"> 1051 <intro> 1052 These functions provide for the allocation and deallocation of 1053 memory used by <jvmti/> functionality and can be used to provide 1054 working memory for agents. 1055 Memory managed by <jvmti/> is not compatible with other memory 1056 allocation libraries and mechanisms. 1057 </intro> 1058 1059 <function id="Allocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="46"> 1060 <synopsis>Allocate</synopsis> 1061 <description> 1062 Allocate an area of memory through the <jvmti/> allocator. 1063 The allocated 1064 memory should be freed with <functionlink id="Deallocate"></functionlink>. 1065 </description> 1066 <origin>jvmdi</origin> 1067 <capabilities> 1068 </capabilities> 1069 <parameters> 1070 <param id="size"> 1071 <jlong/> 1072 <description> 1073 The number of bytes to allocate. 1074 <rationale> 1075 <code>jlong</code> is used for compatibility with JVMDI. 1076 </rationale> 1077 </description> 1078 </param> 1079 <param id="mem_ptr"> 1080 <allocbuf incount="size"><uchar/></allocbuf> 1081 <description> 1082 On return, a pointer to the beginning of the allocated memory. 1083 If <code>size</code> is zero, <code>NULL</code> is returned. 1084 </description> 1085 </param> 1086 </parameters> 1087 <errors> 1088 <error id="JVMTI_ERROR_OUT_OF_MEMORY"> 1089 Memory request cannot be honored. 1090 </error> 1091 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 1092 <paramlink id="size"></paramlink> is less than zero. 1093 </error> 1094 </errors> 1095 </function> 1096 1097 <function id="Deallocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="47"> 1098 <synopsis>Deallocate</synopsis> 1099 <description> 1100 Deallocate <code>mem</code> using the <jvmti/> allocator. 1101 This function should 1102 be used to deallocate any memory allocated and returned 1103 by a <jvmti/> function 1104 (including memory allocated with <functionlink id="Allocate"></functionlink>). 1105 All allocated memory must be deallocated 1106 or the memory cannot be reclaimed. 1107 </description> 1108 <origin>jvmdi</origin> 1109 <capabilities> 1110 </capabilities> 1111 <parameters> 1112 <param id="mem"> 1113 <outbuf> 1114 <uchar/> 1115 <nullok>the call is ignored</nullok> 1116 </outbuf> 1117 <description> 1118 A pointer to the beginning of the allocated memory. 1119 Please ignore "On return, the elements are set." 1120 <todo>keep it from generating "On return, the elements are set"</todo> 1121 </description> 1122 </param> 1123 </parameters> 1124 <errors> 1125 </errors> 1126 </function> 1127 </category> 1128 1129 <category id="threadCategory" label="Thread"> 1130 <intro> 1131 </intro> 1132 1133 <function id="GetThreadState" num="17"> 1134 <synopsis>Get Thread State</synopsis> 1135 <description> 1136 Get the state of a thread. The state of the thread is represented by the 1137 answers to the hierarchical set of questions below: 1138 <ul type="circle"> 1139 <li><i>Alive?</i> 1140 <ul> 1141 <li>Not alive. 1142 <ul type="circle"> 1143 <li><i>Why not alive?</i> 1144 <ul> 1145 <li>New.</li> 1146 <li>Terminated (<datalink 1147 id="JVMTI_THREAD_STATE_TERMINATED"><code>JVMTI_THREAD_STATE_TERMINATED</code></datalink>)</li> 1148 </ul> 1149 </li> 1150 </ul> 1151 </li> 1152 <li>Alive (<datalink 1153 id="JVMTI_THREAD_STATE_ALIVE"><code>JVMTI_THREAD_STATE_ALIVE</code></datalink>) 1154 <ul type="circle"> 1155 <li><i>Suspended?</i> 1156 <ul> 1157 <li>Suspended (<datalink 1158 id="JVMTI_THREAD_STATE_SUSPENDED"><code>JVMTI_THREAD_STATE_SUSPENDED</code></datalink>)</li> 1159 <li>Not suspended</li> 1160 </ul> 1161 </li> 1162 <li><i>Interrupted?</i> 1163 <ul> 1164 <li>Interrupted (<datalink 1165 id="JVMTI_THREAD_STATE_INTERRUPTED"><code>JVMTI_THREAD_STATE_INTERRUPTED</code></datalink>)</li> 1166 <li>Not interrupted.</li> 1167 </ul> 1168 </li> 1169 <li><i>In native?</i> 1170 <ul> 1171 <li>In native code (<datalink 1172 id="JVMTI_THREAD_STATE_IN_NATIVE"><code>JVMTI_THREAD_STATE_IN_NATIVE</code></datalink>)</li> 1173 <li>In Java programming language code</li> 1174 </ul> 1175 </li> 1176 <li><i>What alive state?</i> 1177 <ul> 1178 <li>Runnable (<datalink 1179 id="JVMTI_THREAD_STATE_RUNNABLE"><code>JVMTI_THREAD_STATE_RUNNABLE</code></datalink>)</li> 1180 <li>Blocked (<datalink 1181 id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER"><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></datalink>)</li> 1182 <li>Waiting (<datalink 1183 id="JVMTI_THREAD_STATE_WAITING"><code>JVMTI_THREAD_STATE_WAITING</code></datalink>) 1184 <ul type="circle"> 1185 <li><i>Timed wait?</i> 1186 <ul> 1187 <li>Indefinite (<datalink 1188 id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY"><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></datalink></li> 1189 <li>Timed (<datalink 1190 id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT"><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></datalink>)</li> 1191 </ul> 1192 </li> 1193 <li><i>Why waiting?</i> 1194 <ul> 1195 <li>Object.wait (<datalink 1196 id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT"><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></datalink>)</li> 1197 <li>LockSupport.park (<datalink 1198 id="JVMTI_THREAD_STATE_PARKED"><code>JVMTI_THREAD_STATE_PARKED</code></datalink>)</li> 1199 <li>Sleeping (<datalink 1200 id="JVMTI_THREAD_STATE_SLEEPING"><code>JVMTI_THREAD_STATE_SLEEPING</code></datalink>)</li> 1201 </ul> 1202 </li> 1203 </ul> 1204 </li> 1205 </ul> 1206 </li> 1207 </ul> 1208 </li> 1209 </ul> 1210 </li> 1211 </ul> 1212 <p/> 1213 The answers are represented by the following bit vector. 1214 <constants id="jvmtiThreadState" label="Thread State Flags" kind="bits"> 1215 <constant id="JVMTI_THREAD_STATE_ALIVE" num="0x0001"> 1216 Thread is alive. Zero if thread is new (not started) or terminated. 1217 </constant> 1218 <constant id="JVMTI_THREAD_STATE_TERMINATED" num="0x0002"> 1219 Thread has completed execution. 1220 </constant> 1221 <constant id="JVMTI_THREAD_STATE_RUNNABLE" num="0x0004"> 1222 Thread is runnable. 1223 </constant> 1224 <constant id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER" num="0x0400"> 1225 Thread is waiting to enter a synchronization block/method or, 1226 after an <code>Object.wait()</code>, waiting to re-enter a 1227 synchronization block/method. 1228 </constant> 1229 <constant id="JVMTI_THREAD_STATE_WAITING" num="0x0080"> 1230 Thread is waiting. 1231 </constant> 1232 <constant id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY" num="0x0010"> 1233 Thread is waiting without a timeout. 1234 For example, <code>Object.wait()</code>. 1235 </constant> 1236 <constant id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT" num="0x0020"> 1237 Thread is waiting with a maximum time to wait specified. 1238 For example, <code>Object.wait(long)</code>. 1239 </constant> 1240 <constant id="JVMTI_THREAD_STATE_SLEEPING" num="0x0040"> 1241 Thread is sleeping -- <code>Thread.sleep(long)</code>. 1242 </constant> 1243 <constant id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT" num="0x0100"> 1244 Thread is waiting on an object monitor -- <code>Object.wait</code>. 1245 </constant> 1246 <constant id="JVMTI_THREAD_STATE_PARKED" num="0x0200"> 1247 Thread is parked, for example: <code>LockSupport.park</code>, 1248 <code>LockSupport.parkUtil</code> and <code>LockSupport.parkNanos</code>. 1249 </constant> 1250 <constant id="JVMTI_THREAD_STATE_SUSPENDED" num="0x100000"> 1251 Thread suspended. 1252 <code>java.lang.Thread.suspend()</code> 1253 or a <jvmti/> suspend function 1254 (such as <functionlink id="SuspendThread"></functionlink>) 1255 has been called on the thread. If this bit 1256 is set, the other bits refer to the thread state before suspension. 1257 </constant> 1258 <constant id="JVMTI_THREAD_STATE_INTERRUPTED" num="0x200000"> 1259 Thread has been interrupted. 1260 </constant> 1261 <constant id="JVMTI_THREAD_STATE_IN_NATIVE" num="0x400000"> 1262 Thread is in native code--that is, a native method is running 1263 which has not called back into the VM or Java programming 1264 language code. 1265 <p/> 1266 This flag is not set when running VM compiled Java programming 1267 language code nor is it set when running VM code or 1268 VM support code. Native VM interface functions, such as JNI and 1269 <jvmti/> functions, may be implemented as VM code. 1270 </constant> 1271 <constant id="JVMTI_THREAD_STATE_VENDOR_1" num="0x10000000"> 1272 Defined by VM vendor. 1273 </constant> 1274 <constant id="JVMTI_THREAD_STATE_VENDOR_2" num="0x20000000"> 1275 Defined by VM vendor. 1276 </constant> 1277 <constant id="JVMTI_THREAD_STATE_VENDOR_3" num="0x40000000"> 1278 Defined by VM vendor. 1279 </constant> 1280 </constants> 1281 The following definitions are used to convert <jvmti/> thread state 1282 to <code>java.lang.Thread.State</code> style states. 1283 <constants id="jvmtiJavaLangThreadState" label="java.lang.Thread.State Conversion Masks" kind="bits"> 1284 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_MASK" 1285 num="JVMTI_THREAD_STATE_TERMINATED | JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_RUNNABLE | JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY | JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT"> 1286 Mask the state with this before comparison 1287 </constant> 1288 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_NEW" 1289 num="0"> 1290 <code>java.lang.Thread.State.NEW</code> 1291 </constant> 1292 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED" 1293 num="JVMTI_THREAD_STATE_TERMINATED"> 1294 <code>java.lang.Thread.State.TERMINATED</code> 1295 </constant> 1296 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE" 1297 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_RUNNABLE"> 1298 <code>java.lang.Thread.State.RUNNABLE</code> 1299 </constant> 1300 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED" 1301 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER"> 1302 <code>java.lang.Thread.State.BLOCKED</code> 1303 </constant> 1304 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_WAITING" 1305 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY"> 1306 <code>java.lang.Thread.State.WAITING</code> 1307 </constant> 1308 <constant id="JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING" 1309 num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT"> 1310 <code>java.lang.Thread.State.TIMED_WAITING</code> 1311 </constant> 1312 </constants> 1313 <b>Rules</b> 1314 <p/> 1315 There can be no more than one answer to a question, although there can be no 1316 answer (because the answer is unknown, does not apply, or none of the answers is 1317 correct). An answer is set only when the enclosing answers match. 1318 That is, no more than one of 1319 <ul type="circle"> 1320 <li><code>JVMTI_THREAD_STATE_RUNNABLE</code></li> 1321 <li><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></li> 1322 <li><code>JVMTI_THREAD_STATE_WAITING</code></li> 1323 </ul> 1324 can be set (a <tm>J2SE</tm> compliant implementation will always set 1325 one of these if <code>JVMTI_THREAD_STATE_ALIVE</code> is set). 1326 And if any of these are set, the enclosing answer 1327 <code>JVMTI_THREAD_STATE_ALIVE</code> is set. 1328 No more than one of 1329 <ul type="circle"> 1330 <li><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></li> 1331 <li><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></li> 1332 </ul> 1333 can be set (a <tm>J2SE</tm> compliant implementation will always set 1334 one of these if <code>JVMTI_THREAD_STATE_WAITING</code> is set). 1335 And if either is set, the enclosing answers 1336 <code>JVMTI_THREAD_STATE_ALIVE</code> and 1337 <code>JVMTI_THREAD_STATE_WAITING</code> are set. 1338 No more than one of 1339 <ul type="circle"> 1340 <li><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></li> 1341 <li><code>JVMTI_THREAD_STATE_PARKED</code></li> 1342 <li><code>JVMTI_THREAD_STATE_SLEEPING</code></li> 1343 </ul> 1344 can be set. And if any of these is set, the enclosing answers 1345 <code>JVMTI_THREAD_STATE_ALIVE</code> and 1346 <code>JVMTI_THREAD_STATE_WAITING</code> are set. 1347 Also, if <code>JVMTI_THREAD_STATE_SLEEPING</code> is set, 1348 then <code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code> is set. 1349 If a state <i>A</i> is implemented using the mechanism of 1350 state <i>B</i> then it is state <i>A</i> which 1351 is returned by this function. 1352 For example, if <code>Thread.sleep(long)</code> 1353 is implemented using <code>Object.wait(long)</code> 1354 then it is still <code>JVMTI_THREAD_STATE_SLEEPING</code> 1355 which is returned. 1356 More than one of 1357 <ul type="circle"> 1358 <li><code>JVMTI_THREAD_STATE_SUSPENDED</code></li> 1359 <li><code>JVMTI_THREAD_STATE_INTERRUPTED</code></li> 1360 <li><code>JVMTI_THREAD_STATE_IN_NATIVE</code></li> 1361 </ul> 1362 can be set, but if any is set, 1363 <code>JVMTI_THREAD_STATE_ALIVE</code> is set. 1364 <p/> 1365 And finally, 1366 <code>JVMTI_THREAD_STATE_TERMINATED</code> cannot be set unless 1367 <code>JVMTI_THREAD_STATE_ALIVE</code> is not set. 1368 <p/> 1369 The thread state representation is designed for extension in future versions 1370 of the specification; thread state values should be used accordingly, that is 1371 they should not be used as ordinals. 1372 Most queries can be made by testing a single bit, if use in a switch statement is desired, 1373 the state bits should be masked with the interesting bits. 1374 All bits not defined above are reserved for future use. 1375 A VM, compliant to the current specification, must set reserved bits to zero. 1376 An agent should ignore reserved bits -- 1377 they should not be assumed to be zero and thus should not be included in comparisons. 1378 <p/> 1379 <b>Examples</b> 1380 <p/> 1381 Note that the values below exclude reserved and vendor bits. 1382 <p/> 1383 The state of a thread blocked at a <code>synchronized</code>-statement would be: 1384 <example> 1385 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER 1386 </example> 1387 The state of a thread which hasn't started yet would be: 1388 <example> 1389 0 1390 </example> 1391 The state of a thread at a <code>Object.wait(3000)</code> would be: 1392 <example> 1393 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_WAITING + 1394 JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT + 1395 JVMTI_THREAD_STATE_MONITOR_WAITING 1396 </example> 1397 The state of a thread suspended while runnable would be: 1398 <example> 1399 JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_RUNNABLE + JVMTI_THREAD_STATE_SUSPENDED 1400 </example> 1401 <p/> 1402 <b>Testing the State</b> 1403 <p/> 1404 In most cases, the thread state can be determined by testing the one bit corresponding 1405 to that question. For example, the code to test if a thread is sleeping: 1406 <example> 1407 jint state; 1408 jvmtiError err; 1409 1410 err = (*jvmti)->GetThreadState(jvmti, thread, &state); 1411 if (err == JVMTI_ERROR_NONE) { 1412 if (state & JVMTI_THREAD_STATE_SLEEPING) { ... 1413 </example> 1414 <p/> 1415 For waiting (that is, in <code>Object.wait</code>, parked, or sleeping) it would be: 1416 <example> 1417 if (state & JVMTI_THREAD_STATE_WAITING) { ... 1418 </example> 1419 For some states, more than one bit will need to be tested as is the case 1420 when testing if a thread has not yet been started: 1421 <example> 1422 if ((state & (JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_TERMINATED)) == 0) { ... 1423 </example> 1424 To distinguish timed from untimed <code>Object.wait</code>: 1425 <example> 1426 if (state & JVMTI_THREAD_STATE_IN_OBJECT_WAIT) { 1427 if (state & JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT) { 1428 printf("in Object.wait(long timeout)\n"); 1429 } else { 1430 printf("in Object.wait()\n"); 1431 } 1432 } 1433 </example> 1434 <p/> 1435 <b>Relationship to <code>java.lang.Thread.State</code></b> 1436 <p/> 1437 The thread state represented by <code>java.lang.Thread.State</code> 1438 returned from <code>java.lang.Thread.getState()</code> is a subset of the 1439 information returned from this function. 1440 The corresponding <code>java.lang.Thread.State</code> can be determined 1441 by using the provided conversion masks. 1442 For example, this returns the name of the <code>java.lang.Thread.State</code> thread state: 1443 <example> 1444 err = (*jvmti)->GetThreadState(jvmti, thread, &state); 1445 abortOnError(err); 1446 switch (state & JVMTI_JAVA_LANG_THREAD_STATE_MASK) { 1447 case JVMTI_JAVA_LANG_THREAD_STATE_NEW: 1448 return "NEW"; 1449 case JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED: 1450 return "TERMINATED"; 1451 case JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE: 1452 return "RUNNABLE"; 1453 case JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED: 1454 return "BLOCKED"; 1455 case JVMTI_JAVA_LANG_THREAD_STATE_WAITING: 1456 return "WAITING"; 1457 case JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING: 1458 return "TIMED_WAITING"; 1459 } 1460 </example> 1461 </description> 1462 <origin>new</origin> 1463 <capabilities> 1464 </capabilities> 1465 <parameters> 1466 <param id="thread"> 1467 <jthread null="current" started="maybe" impl="noconvert"/> 1468 <description> 1469 The thread to query. 1470 </description> 1471 </param> 1472 <param id="thread_state_ptr"> 1473 <outptr><jint/></outptr> 1474 <description> 1475 On return, points to state flags, 1476 as defined by the <internallink id="jvmtiThreadState">Thread State Flags</internallink>. 1477 </description> 1478 </param> 1479 </parameters> 1480 <errors> 1481 </errors> 1482 </function> 1483 1484 <function id="GetCurrentThread" phase="start" num="18" since="1.1"> 1485 <synopsis>Get Current Thread</synopsis> 1486 <description> 1487 Get the current thread. 1488 The current thread is the Java programming language thread which has called the function. 1489 The function may return <code>NULL</code> in the start phase if the 1490 <internallink id="jvmtiCapabilities.can_generate_early_vmstart"> 1491 <code>can_generate_early_vmstart</code></internallink> capability is enabled 1492 and the <code>java.lang.Thread</code> class has not been initialized yet. 1493 <p/> 1494 Note that most <jvmti/> functions that take a thread 1495 as an argument will accept <code>NULL</code> to mean 1496 the current thread. 1497 </description> 1498 <origin>new</origin> 1499 <capabilities> 1500 </capabilities> 1501 <parameters> 1502 <param id="thread_ptr"> 1503 <outptr><jthread/></outptr> 1504 <description> 1505 On return, points to the current thread, or <code>NULL</code>. 1506 </description> 1507 </param> 1508 </parameters> 1509 <errors> 1510 </errors> 1511 </function> 1512 1513 <function id="GetAllThreads" num="4"> 1514 <synopsis>Get All Threads</synopsis> 1515 <description> 1516 Get all live threads. 1517 The threads are Java programming language threads; 1518 that is, threads that are attached to the VM. 1519 A thread is live if <code>java.lang.Thread.isAlive()</code> 1520 would return <code>true</code>, that is, the thread has 1521 been started and has not yet died. 1522 The universe of threads is determined by the context of the <jvmti/> 1523 environment, which typically is all threads attached to the VM. 1524 Note that this includes <jvmti/> agent threads 1525 (see <functionlink id="RunAgentThread"/>). 1526 </description> 1527 <origin>jvmdi</origin> 1528 <capabilities> 1529 </capabilities> 1530 <parameters> 1531 <param id="threads_count_ptr"> 1532 <outptr><jint/></outptr> 1533 <description> 1534 On return, points to the number of running threads. 1535 </description> 1536 </param> 1537 <param id="threads_ptr"> 1538 <allocbuf outcount="threads_count_ptr"><jthread/></allocbuf> 1539 <description> 1540 On return, points to an array of references, one 1541 for each running thread. 1542 </description> 1543 </param> 1544 </parameters> 1545 <errors> 1546 </errors> 1547 </function> 1548 1549 <function id="SuspendThread" num="5"> 1550 <synopsis>Suspend Thread</synopsis> 1551 <description> 1552 Suspend the specified thread. If the calling thread is specified, 1553 this function will not return until some other thread calls 1554 <functionlink id="ResumeThread"></functionlink>. 1555 If the thread is currently suspended, this function 1556 does nothing and returns an error. 1557 </description> 1558 <origin>jvmdi</origin> 1559 <capabilities> 1560 <required id="can_suspend"></required> 1561 </capabilities> 1562 <parameters> 1563 <param id="thread"> 1564 <jthread null="current"/> 1565 <description> 1566 The thread to suspend. 1567 </description> 1568 </param> 1569 </parameters> 1570 <errors> 1571 <error id="JVMTI_ERROR_THREAD_SUSPENDED"> 1572 Thread already suspended. 1573 </error> 1574 </errors> 1575 </function> 1576 1577 <elide> 1578 <function id="SuspendAllThreads" num="101"> 1579 <synopsis>Suspend All Threads</synopsis> 1580 <description> 1581 <issue> 1582 There has been no explicit call for this function, and it will 1583 thus be removed if there is no interest. 1584 </issue> 1585 Suspend all live threads except: 1586 <ul> 1587 <li>already suspended threads</li> 1588 <li>those listed in <paramlink id="except_list"></paramlink></li> 1589 <li>certain system (non application) threads, as determined 1590 by the VM implementation</li> 1591 </ul> 1592 The threads are Java programming language threads; 1593 native threads which are not attached to the VM are not 1594 Java programming language threads. 1595 A thread is live if <code>java.lang.Thread.isAlive()</code> 1596 would return <code>true</code>, that is, the thread has 1597 been started and has not yet died. 1598 The universe of threads is determined 1599 by the context of the <jvmti/> 1600 environment, which, typically, is all threads attached to the VM, 1601 except critical VM internal threads and <jvmti/> agent threads 1602 (see <functionlink id="RunAgentThread"/>). 1603 <p/> 1604 If the calling thread is specified, 1605 all other threads are suspended first then the caller thread is suspended - 1606 this function will not return until some other thread calls 1607 <functionlink id="ResumeThread"></functionlink>. 1608 <p/> 1609 The list of actually 1610 suspended threads is returned in 1611 <paramlink id="suspended_list_ptr"></paramlink>. 1612 Suspension is as defined in <functionlink id="SuspendThread"></functionlink>. 1613 <functionlink id="ResumeThreadList"></functionlink> 1614 can be used to resume the suspended threads. 1615 </description> 1616 <origin>new</origin> 1617 <capabilities> 1618 <required id="can_suspend"></required> 1619 </capabilities> 1620 <parameters> 1621 <param id="except_count"> 1622 <jint min="0"/> 1623 <description> 1624 The number of threads in the list of threads not to be suspended. 1625 </description> 1626 </param> 1627 <param id="except_list"> 1628 <inbuf incount="except_count"> 1629 <jthread/> 1630 <nullok>not an error if <code>except_count == 0</code></nullok> 1631 </inbuf> 1632 <description> 1633 The list of threads not to be suspended. 1634 </description> 1635 </param> 1636 <param id="suspended_count_ptr"> 1637 <outptr><jint/></outptr> 1638 <description> 1639 On return, points to the number of threads suspended by this call. 1640 </description> 1641 </param> 1642 <param id="suspended_list_ptr"> 1643 <allocbuf outcount="suspended_count_ptr"><jthread/></allocbuf> 1644 <description> 1645 On return, points to an array of references, one 1646 for each thread suspended. 1647 </description> 1648 </param> 1649 </parameters> 1650 <errors> 1651 <error id="JVMTI_ERROR_INVALID_THREAD"> 1652 A thread in <paramlink id="except_list"></paramlink> was invalid. 1653 </error> 1654 <error id="JVMTI_ERROR_NULL_POINTER"> 1655 Both <paramlink id="except_list"></paramlink> was <code>NULL</code> 1656 and <paramlink id="except_count"></paramlink> was non-zero. 1657 </error> 1658 </errors> 1659 </function> 1660 </elide> 1661 1662 <function id="SuspendThreadList" num="92"> 1663 <synopsis>Suspend Thread List</synopsis> 1664 <description> 1665 Suspend the <paramlink id="request_count"></paramlink> 1666 threads specified in the 1667 <paramlink id="request_list"></paramlink> array. 1668 Threads may be resumed with 1669 <functionlink id="ResumeThreadList"></functionlink> or 1670 <functionlink id="ResumeThread"></functionlink>. 1671 If the calling thread is specified in the 1672 <paramlink id="request_list"></paramlink> array, this function will 1673 not return until some other thread resumes it. 1674 Errors encountered in the suspension of a thread 1675 are returned in the <paramlink id="results"></paramlink> 1676 array, <b>not</b> in the return value of this function. 1677 Threads that are currently suspended do not change state. 1678 </description> 1679 <origin>jvmdi</origin> 1680 <capabilities> 1681 <required id="can_suspend"></required> 1682 </capabilities> 1683 <parameters> 1684 <param id="request_count"> 1685 <jint min="0"/> 1686 <description> 1687 The number of threads to suspend. 1688 </description> 1689 </param> 1690 <param id="request_list"> 1691 <inbuf incount="request_count"><jthread/></inbuf> 1692 <description> 1693 The list of threads to suspend. 1694 </description> 1695 </param> 1696 <param id="results"> 1697 <outbuf incount="request_count"><enum>jvmtiError</enum></outbuf> 1698 <description> 1699 An agent supplied array of 1700 <paramlink id="request_count"></paramlink> elements. 1701 On return, filled with the error code for 1702 the suspend of the corresponding thread. 1703 The error code will be 1704 <errorlink id="JVMTI_ERROR_NONE"></errorlink> 1705 if the thread was suspended by this call. 1706 Possible error codes are those specified 1707 for <functionlink id="SuspendThread"></functionlink>. 1708 </description> 1709 </param> 1710 </parameters> 1711 <errors> 1712 </errors> 1713 </function> 1714 1715 <function id="ResumeThread" num="6"> 1716 <synopsis>Resume Thread</synopsis> 1717 <description> 1718 Resume a suspended thread. 1719 Any threads currently suspended through 1720 a <jvmti/> suspend function (eg. 1721 <functionlink id="SuspendThread"></functionlink>) 1722 or <code>java.lang.Thread.suspend()</code> 1723 will resume execution; 1724 all other threads are unaffected. 1725 </description> 1726 <origin>jvmdi</origin> 1727 <capabilities> 1728 <required id="can_suspend"></required> 1729 </capabilities> 1730 <parameters> 1731 <param id="thread"> 1732 <jthread/> 1733 <description> 1734 The thread to resume. 1735 </description> 1736 </param> 1737 </parameters> 1738 <errors> 1739 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED"> 1740 Thread was not suspended. 1741 </error> 1742 <error id="JVMTI_ERROR_INVALID_TYPESTATE"> 1743 The state of the thread has been modified, and is now inconsistent. 1744 </error> 1745 </errors> 1746 </function> 1747 1748 <function id="ResumeThreadList" num="93"> 1749 <synopsis>Resume Thread List</synopsis> 1750 <description> 1751 Resume the <paramlink id="request_count"></paramlink> 1752 threads specified in the 1753 <paramlink id="request_list"></paramlink> array. 1754 Any thread suspended through 1755 a <jvmti/> suspend function (eg. 1756 <functionlink id="SuspendThreadList"></functionlink>) 1757 or <code>java.lang.Thread.suspend()</code> 1758 will resume execution. 1759 </description> 1760 <origin>jvmdi</origin> 1761 <capabilities> 1762 <required id="can_suspend"></required> 1763 </capabilities> 1764 <parameters> 1765 <param id="request_count"> 1766 <jint min="0"/> 1767 <description> 1768 The number of threads to resume. 1769 </description> 1770 </param> 1771 <param id="request_list"> 1772 <inbuf incount="request_count"><jthread/></inbuf> 1773 <description> 1774 The threads to resume. 1775 </description> 1776 </param> 1777 <param id="results"> 1778 <outbuf incount="request_count"><enum>jvmtiError</enum></outbuf> 1779 <description> 1780 An agent supplied array of 1781 <paramlink id="request_count"></paramlink> elements. 1782 On return, filled with the error code for 1783 the resume of the corresponding thread. 1784 The error code will be 1785 <errorlink id="JVMTI_ERROR_NONE"></errorlink> 1786 if the thread was suspended by this call. 1787 Possible error codes are those specified 1788 for <functionlink id="ResumeThread"></functionlink>. 1789 </description> 1790 </param> 1791 </parameters> 1792 <errors> 1793 </errors> 1794 </function> 1795 1796 <function id="StopThread" num="7"> 1797 <synopsis>Stop Thread</synopsis> 1798 <description> 1799 Send the specified asynchronous exception to the specified thread 1800 (similar to <code>java.lang.Thread.stop</code>). 1801 Normally, this function is used to kill the specified thread with an 1802 instance of the exception <code>ThreadDeath</code>. 1803 </description> 1804 <origin>jvmdi</origin> 1805 <capabilities> 1806 <required id="can_signal_thread"></required> 1807 </capabilities> 1808 <parameters> 1809 <param id="thread"> 1810 <jthread/> 1811 <description> 1812 The thread to stop. 1813 </description> 1814 </param> 1815 <param id="exception"> 1816 <jobject/> 1817 <description> 1818 The asynchronous exception object. 1819 </description> 1820 </param> 1821 </parameters> 1822 <errors> 1823 </errors> 1824 </function> 1825 1826 <function id="InterruptThread" num="8"> 1827 <synopsis>Interrupt Thread</synopsis> 1828 <description> 1829 Interrupt the specified thread 1830 (similar to <code>java.lang.Thread.interrupt</code>). 1831 </description> 1832 <origin>jvmdi</origin> 1833 <capabilities> 1834 <required id="can_signal_thread"></required> 1835 </capabilities> 1836 <parameters> 1837 <param id="thread"> 1838 <jthread impl="noconvert"/> 1839 <description> 1840 The thread to interrupt. 1841 </description> 1842 </param> 1843 </parameters> 1844 <errors> 1845 </errors> 1846 </function> 1847 1848 <function id="GetThreadInfo" num="9"> 1849 <synopsis>Get Thread Info</synopsis> 1850 <typedef id="jvmtiThreadInfo" label="Thread information structure"> 1851 <field id="name"> 1852 <allocfieldbuf><char/></allocfieldbuf> 1853 <description> 1854 The thread name, encoded as a 1855 <internallink id="mUTF">modified UTF-8</internallink> string. 1856 </description> 1857 </field> 1858 <field id="priority"> 1859 <jint/> 1860 <description> 1861 The thread priority. See the thread priority constants: 1862 <datalink id="jvmtiThreadPriority"></datalink>. 1863 </description> 1864 </field> 1865 <field id="is_daemon"> 1866 <jboolean/> 1867 <description> 1868 Is this a daemon thread? 1869 </description> 1870 </field> 1871 <field id="thread_group"> 1872 <jthreadGroup/> 1873 <description> 1874 The thread group to which this thread belongs. 1875 <code>NULL</code> if the thread has died. 1876 </description> 1877 </field> 1878 <field id="context_class_loader"> 1879 <jobject/> 1880 <description> 1881 The context class loader associated with this thread. 1882 </description> 1883 </field> 1884 </typedef> 1885 <description> 1886 Get thread information. The fields of the <datalink id="jvmtiThreadInfo"/> structure 1887 are filled in with details of the specified thread. 1888 </description> 1889 <origin>jvmdi</origin> 1890 <capabilities> 1891 </capabilities> 1892 <parameters> 1893 <param id="thread"> 1894 <jthread null="current" impl="noconvert" started="maybe"/> 1895 <description> 1896 The thread to query. 1897 </description> 1898 </param> 1899 <param id="info_ptr"> 1900 <outptr><struct>jvmtiThreadInfo</struct></outptr> 1901 <description> 1902 On return, filled with information describing the specified thread. 1903 </description> 1904 </param> 1905 </parameters> 1906 <errors> 1907 </errors> 1908 </function> 1909 1910 <function id="GetOwnedMonitorInfo" num="10"> 1911 <synopsis>Get Owned Monitor Info</synopsis> 1912 <description> 1913 Get information about the monitors owned by the 1914 specified thread. 1915 </description> 1916 <origin>jvmdiClone</origin> 1917 <capabilities> 1918 <required id="can_get_owned_monitor_info"></required> 1919 </capabilities> 1920 <parameters> 1921 <param id="thread"> 1922 <jthread null="current"/> 1923 <description> 1924 The thread to query. 1925 </description> 1926 </param> 1927 <param id="owned_monitor_count_ptr"> 1928 <outptr><jint/></outptr> 1929 <description> 1930 The number of monitors returned. 1931 </description> 1932 </param> 1933 <param id="owned_monitors_ptr"> 1934 <allocbuf outcount="owned_monitor_count_ptr"><jobject/></allocbuf> 1935 <description> 1936 The array of owned monitors. 1937 </description> 1938 </param> 1939 </parameters> 1940 <errors> 1941 </errors> 1942 </function> 1943 1944 <function id="GetOwnedMonitorStackDepthInfo" num="153" since="1.1"> 1945 <synopsis>Get Owned Monitor Stack Depth Info</synopsis> 1946 <typedef id="jvmtiMonitorStackDepthInfo" 1947 label="Monitor stack depth information structure"> 1948 <field id="monitor"> 1949 <jobject/> 1950 <description> 1951 The owned monitor. 1952 </description> 1953 </field> 1954 <field id="stack_depth"> 1955 <jint/> 1956 <description> 1957 The stack depth. Corresponds to the stack depth used in the 1958 <internallink id="stack">Stack Frame functions</internallink>. 1959 That is, zero is the current frame, one is the frame which 1960 called the current frame. And it is negative one if the 1961 implementation cannot determine the stack depth (e.g., for 1962 monitors acquired by JNI <code>MonitorEnter</code>). 1963 </description> 1964 </field> 1965 </typedef> 1966 <description> 1967 Get information about the monitors owned by the 1968 specified thread and the depth of the stack frame which locked them. 1969 </description> 1970 <origin>new</origin> 1971 <capabilities> 1972 <required id="can_get_owned_monitor_stack_depth_info"></required> 1973 </capabilities> 1974 <parameters> 1975 <param id="thread"> 1976 <jthread null="current"/> 1977 <description> 1978 The thread to query. 1979 </description> 1980 </param> 1981 <param id="monitor_info_count_ptr"> 1982 <outptr><jint/></outptr> 1983 <description> 1984 The number of monitors returned. 1985 </description> 1986 </param> 1987 <param id="monitor_info_ptr"> 1988 <allocbuf outcount="monitor_info_count_ptr"> 1989 <struct>jvmtiMonitorStackDepthInfo</struct> 1990 </allocbuf> 1991 <description> 1992 The array of owned monitor depth information. 1993 </description> 1994 </param> 1995 </parameters> 1996 <errors> 1997 </errors> 1998 </function> 1999 2000 <function id="GetCurrentContendedMonitor" num="11"> 2001 <synopsis>Get Current Contended Monitor</synopsis> 2002 <description> 2003 Get the object, if any, whose monitor the specified thread is waiting to 2004 enter or waiting to regain through <code>java.lang.Object.wait</code>. 2005 </description> 2006 <origin>jvmdi</origin> 2007 <capabilities> 2008 <required id="can_get_current_contended_monitor"></required> 2009 </capabilities> 2010 <parameters> 2011 <param id="thread"> 2012 <jthread null="current"/> 2013 <description> 2014 The thread to query. 2015 </description> 2016 </param> 2017 <param id="monitor_ptr"> 2018 <outptr><jobject/></outptr> 2019 <description> 2020 On return, filled with the current contended monitor, or 2021 NULL if there is none. 2022 </description> 2023 </param> 2024 </parameters> 2025 <errors> 2026 </errors> 2027 </function> 2028 2029 <callback id="jvmtiStartFunction"> 2030 <void/> 2031 <synopsis>Agent Start Function</synopsis> 2032 <description> 2033 Agent supplied callback function. 2034 This function is the entry point for an agent thread 2035 started with 2036 <functionlink id="RunAgentThread"></functionlink>. 2037 </description> 2038 <parameters> 2039 <param id="jvmti_env"> 2040 <outptr> 2041 <struct>jvmtiEnv</struct> 2042 </outptr> 2043 <description> 2044 The <jvmti/> environment. 2045 </description> 2046 </param> 2047 <param id="jni_env"> 2048 <outptr> 2049 <struct>JNIEnv</struct> 2050 </outptr> 2051 <description> 2052 The JNI environment. 2053 </description> 2054 </param> 2055 <param id="arg"> 2056 <outptr> 2057 <void/> 2058 </outptr> 2059 <description> 2060 The <code>arg</code> parameter passed to 2061 <functionlink id="RunAgentThread"></functionlink>. 2062 </description> 2063 </param> 2064 </parameters> 2065 </callback> 2066 2067 <function id="RunAgentThread" num="12"> 2068 <synopsis>Run Agent Thread</synopsis> 2069 <description> 2070 Starts the execution of an agent thread. with the specified native function. 2071 The parameter <paramlink id="arg"></paramlink> is forwarded on to the 2072 <functionlink id="jvmtiStartFunction">start function</functionlink> 2073 (specified with <paramlink id="proc"></paramlink>) as its single argument. 2074 This function allows the creation of agent threads 2075 for handling communication with another process or for handling events 2076 without the need to load a special subclass of <code>java.lang.Thread</code> or 2077 implementer of <code>java.lang.Runnable</code>. 2078 Instead, the created thread can run entirely in native code. 2079 However, the created thread does require a newly created instance 2080 of <code>java.lang.Thread</code> (referenced by the argument <code>thread</code>) to 2081 which it will be associated. 2082 The thread object can be created with JNI calls. 2083 <p/> 2084 The following common thread priorities are provided for your convenience: 2085 <constants id="jvmtiThreadPriority" label="Thread Priority Constants" kind="const"> 2086 <constant id="JVMTI_THREAD_MIN_PRIORITY" num="1"> 2087 Minimum possible thread priority 2088 </constant> 2089 <constant id="JVMTI_THREAD_NORM_PRIORITY" num="5"> 2090 Normal thread priority 2091 </constant> 2092 <constant id="JVMTI_THREAD_MAX_PRIORITY" num="10"> 2093 Maximum possible thread priority 2094 </constant> 2095 </constants> 2096 <p/> 2097 The new thread is started as a daemon thread with the specified 2098 <paramlink id="priority"></paramlink>. 2099 If enabled, a <eventlink id="ThreadStart"/> event will be sent. 2100 <p/> 2101 Since the thread has been started, the thread will be live when this function 2102 returns, unless the thread has died immediately. 2103 <p/> 2104 The thread group of the thread is ignored -- specifically, the thread is not 2105 added to the thread group and the thread is not seen on queries of the thread 2106 group at either the Java programming language or <jvmti/> levels. 2107 <p/> 2108 The thread is not visible to Java programming language queries but is 2109 included in <jvmti/> queries (for example, 2110 <functionlink id="GetAllThreads"/> and 2111 <functionlink id="GetAllStackTraces"/>). 2112 <p/> 2113 Upon execution of <code>proc</code>, the new thread will be attached to the 2114 VM -- see the JNI documentation on 2115 <externallink id="jni/invocation.html#attaching-to-the-vm" 2116 >Attaching to the VM</externallink>. 2117 </description> 2118 <origin>jvmdiClone</origin> 2119 <capabilities> 2120 </capabilities> 2121 <parameters> 2122 <param id="thread"> 2123 <jthread impl="noconvert" started="no"/> 2124 <description> 2125 The thread to run. 2126 </description> 2127 </param> 2128 <param id="proc"> 2129 <ptrtype> 2130 <struct>jvmtiStartFunction</struct> 2131 </ptrtype> 2132 <description> 2133 The start function. 2134 </description> 2135 </param> 2136 <param id="arg"> 2137 <inbuf> 2138 <void/> 2139 <nullok><code>NULL</code> is passed to the start function</nullok> 2140 </inbuf> 2141 <description> 2142 The argument to the start function. 2143 </description> 2144 </param> 2145 <param id="priority"> 2146 <jint/> 2147 <description> 2148 The priority of the started thread. Any thread 2149 priority allowed by <code>java.lang.Thread.setPriority</code> can be used including 2150 those in <datalink id="jvmtiThreadPriority"></datalink>. 2151 </description> 2152 </param> 2153 </parameters> 2154 <errors> 2155 <error id="JVMTI_ERROR_INVALID_PRIORITY"> 2156 <paramlink id="priority"/> is less than 2157 <datalink id="JVMTI_THREAD_MIN_PRIORITY"/> 2158 or greater than 2159 <datalink id="JVMTI_THREAD_MAX_PRIORITY"/> 2160 </error> 2161 </errors> 2162 </function> 2163 2164 <function id="SetThreadLocalStorage" jkernel="yes" impl="notrace" phase="start" num="103"> 2165 <synopsis>Set Thread Local Storage</synopsis> 2166 <description> 2167 The VM stores a pointer value associated with each environment-thread 2168 pair. This pointer value is called <i>thread-local storage</i>. 2169 This value is <code>NULL</code> unless set with this function. 2170 Agents can allocate memory in which they store thread specific 2171 information. By setting thread-local storage it can then be 2172 accessed with 2173 <functionlink id="GetThreadLocalStorage"></functionlink>. 2174 <p/> 2175 This function is called by the agent to set the value of the <jvmti/> 2176 thread-local storage. <jvmti/> supplies to the agent a pointer-size 2177 thread-local storage that can be used to record per-thread 2178 information. 2179 </description> 2180 <origin>jvmpi</origin> 2181 <capabilities> 2182 </capabilities> 2183 <parameters> 2184 <param id="thread"> 2185 <jthread null="current"/> 2186 <description> 2187 Store to this thread. 2188 </description> 2189 </param> 2190 <param id="data"> 2191 <inbuf> 2192 <void/> 2193 <nullok>value is set to <code>NULL</code></nullok> 2194 </inbuf> 2195 <description> 2196 The value to be entered into the thread-local storage. 2197 </description> 2198 </param> 2199 </parameters> 2200 <errors> 2201 </errors> 2202 </function> 2203 2204 <function id="GetThreadLocalStorage" jkernel="yes" impl="innative notrace" phase="start" num="102"> 2205 <synopsis>Get Thread Local Storage</synopsis> 2206 <description> 2207 Called by the agent to get the value of the <jvmti/> thread-local 2208 storage. 2209 </description> 2210 <origin>jvmpi</origin> 2211 <capabilities> 2212 </capabilities> 2213 <parameters> 2214 <param id="thread"> 2215 <jthread null="current" impl="noconvert"/> 2216 <description> 2217 Retrieve from this thread. 2218 </description> 2219 </param> 2220 <param id="data_ptr"> 2221 <agentbuf><void/></agentbuf> 2222 <description> 2223 Pointer through which the value of the thread local 2224 storage is returned. 2225 If thread-local storage has not been set with 2226 <functionlink id="SetThreadLocalStorage"></functionlink> the returned 2227 pointer is <code>NULL</code>. 2228 </description> 2229 </param> 2230 </parameters> 2231 <errors> 2232 </errors> 2233 </function> 2234 2235 </category> 2236 2237 <category id="thread_groups" label="Thread Group"> 2238 <intro> 2239 </intro> 2240 2241 <function id="GetTopThreadGroups" num="13"> 2242 <synopsis>Get Top Thread Groups</synopsis> 2243 <description> 2244 Return all top-level (parentless) thread groups in the VM. 2245 </description> 2246 <origin>jvmdi</origin> 2247 <capabilities> 2248 </capabilities> 2249 <parameters> 2250 <param id="group_count_ptr"> 2251 <outptr><jint/></outptr> 2252 <description> 2253 On return, points to the number of top-level thread groups. 2254 </description> 2255 </param> 2256 <param id="groups_ptr"> 2257 <allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf> 2258 <description> 2259 On return, refers to a pointer to the top-level thread group array. 2260 </description> 2261 </param> 2262 </parameters> 2263 <errors> 2264 </errors> 2265 </function> 2266 2267 <function id="GetThreadGroupInfo" num="14"> 2268 <synopsis>Get Thread Group Info</synopsis> 2269 <typedef id="jvmtiThreadGroupInfo" label="Thread group information structure"> 2270 <field id="parent"> 2271 <jthreadGroup/> 2272 <description> 2273 The parent thread group. 2274 </description> 2275 </field> 2276 <field id="name"> 2277 <allocfieldbuf><char/></allocfieldbuf> 2278 <description> 2279 The thread group's name, encoded as a 2280 <internallink id="mUTF">modified UTF-8</internallink> string. 2281 </description> 2282 </field> 2283 <field id="max_priority"> 2284 <jint/> 2285 <description> 2286 The maximum priority for this thread group. 2287 </description> 2288 </field> 2289 <field id="is_daemon"> 2290 <jboolean/> 2291 <description> 2292 Is this a daemon thread group? 2293 </description> 2294 </field> 2295 </typedef> 2296 <description> 2297 Get information about the thread group. The fields of the 2298 <functionlink id="jvmtiThreadGroupInfo"></functionlink> structure 2299 are filled in with details of the specified thread group. 2300 </description> 2301 <origin>jvmdi</origin> 2302 <capabilities> 2303 </capabilities> 2304 <parameters> 2305 <param id="group"> 2306 <jthreadGroup/> 2307 <description> 2308 The thread group to query. 2309 </description> 2310 </param> 2311 <param id="info_ptr"> 2312 <outptr><struct>jvmtiThreadGroupInfo</struct></outptr> 2313 <description> 2314 On return, filled with information describing the specified 2315 thread group. 2316 </description> 2317 </param> 2318 </parameters> 2319 <errors> 2320 </errors> 2321 </function> 2322 2323 <function id="GetThreadGroupChildren" num="15"> 2324 <synopsis>Get Thread Group Children</synopsis> 2325 <description> 2326 Get the live threads and active subgroups in this thread group. 2327 </description> 2328 <origin>jvmdi</origin> 2329 <capabilities> 2330 </capabilities> 2331 <parameters> 2332 <param id="group"> 2333 <jthreadGroup/> 2334 <description> 2335 The group to query. 2336 </description> 2337 </param> 2338 <param id="thread_count_ptr"> 2339 <outptr><jint/></outptr> 2340 <description> 2341 On return, points to the number of live threads in this thread group. 2342 </description> 2343 </param> 2344 <param id="threads_ptr"> 2345 <allocbuf outcount="thread_count_ptr"><jthread/></allocbuf> 2346 <description> 2347 On return, points to an array of the live threads in this thread group. 2348 </description> 2349 </param> 2350 <param id="group_count_ptr"> 2351 <outptr><jint/></outptr> 2352 <description> 2353 On return, points to the number of active child thread groups 2354 </description> 2355 </param> 2356 <param id="groups_ptr"> 2357 <allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf> 2358 <description> 2359 On return, points to an array of the active child thread groups. 2360 </description> 2361 </param> 2362 </parameters> 2363 <errors> 2364 </errors> 2365 </function> 2366 </category> 2367 2368 <category id="stack" label="Stack Frame"> 2369 <intro> 2370 These functions provide information about the stack of a thread. 2371 Stack frames are referenced by depth. 2372 The frame at depth zero is the current frame. 2373 <p/> 2374 Stack frames are as described in 2375 <vmspec chapter="3.6"/>, 2376 That is, they correspond to method 2377 invocations (including native methods) but do not correspond to platform native or 2378 VM internal frames. 2379 <p/> 2380 A <jvmti/> implementation may use method invocations to launch a thread and 2381 the corresponding frames may be included in the stack as presented by these functions -- 2382 that is, there may be frames shown 2383 deeper than <code>main()</code> and <code>run()</code>. 2384 However this presentation must be consistent across all <jvmti/> functionality which 2385 uses stack frames or stack depth. 2386 </intro> 2387 2388 <typedef id="jvmtiFrameInfo" label="Stack frame information structure"> 2389 <description> 2390 Information about a stack frame is returned in this structure. 2391 </description> 2392 <field id="method"> 2393 <jmethodID/> 2394 <description> 2395 The method executing in this frame. 2396 </description> 2397 </field> 2398 <field id="location"> 2399 <jlocation/> 2400 <description> 2401 The index of the instruction executing in this frame. 2402 <code>-1</code> if the frame is executing a native method. 2403 </description> 2404 </field> 2405 </typedef> 2406 2407 <typedef id="jvmtiStackInfo" label="Stack information structure"> 2408 <description> 2409 Information about a set of stack frames is returned in this structure. 2410 </description> 2411 <field id="thread"> 2412 <jthread/> 2413 <description> 2414 On return, the thread traced. 2415 </description> 2416 </field> 2417 <field id="state"> 2418 <jint/> 2419 <description> 2420 On return, the thread state. See <functionlink id="GetThreadState"></functionlink>. 2421 </description> 2422 </field> 2423 <field id="frame_buffer"> 2424 <outbuf incount="max_frame_count"> 2425 <struct>jvmtiFrameInfo</struct> 2426 </outbuf> 2427 <description> 2428 On return, this agent allocated buffer is filled 2429 with stack frame information. 2430 </description> 2431 </field> 2432 <field id="frame_count"> 2433 <jint/> 2434 <description> 2435 On return, the number of records filled into 2436 <code>frame_buffer</code>. 2437 This will be 2438 min(<code>max_frame_count</code>, <i>stackDepth</i>). 2439 </description> 2440 </field> 2441 </typedef> 2442 2443 <function id="GetStackTrace" num="104"> 2444 <synopsis>Get Stack Trace</synopsis> 2445 <description> 2446 Get information about the stack of a thread. 2447 If <paramlink id="max_frame_count"></paramlink> is less than the depth of the stack, 2448 the <paramlink id="max_frame_count"></paramlink> topmost frames are returned, 2449 otherwise the entire stack is returned. 2450 The topmost frames, those most recently invoked, are at the beginning of the returned buffer. 2451 <p/> 2452 The following example causes up to five of the topmost frames 2453 to be returned and (if there are any frames) the currently 2454 executing method name to be printed. 2455 <example> 2456jvmtiFrameInfo frames[5]; 2457jint count; 2458jvmtiError err; 2459 2460err = (*jvmti)->GetStackTrace(jvmti, aThread, 0, 5, 2461 frames, &count); 2462if (err == JVMTI_ERROR_NONE && count >= 1) { 2463 char *methodName; 2464 err = (*jvmti)->GetMethodName(jvmti, frames[0].method, 2465 &methodName, NULL, NULL); 2466 if (err == JVMTI_ERROR_NONE) { 2467 printf("Executing method: %s", methodName); 2468 } 2469} 2470 </example> 2471 <todo> 2472 check example code. 2473 </todo> 2474 <p/> 2475 The <paramlink id="thread"></paramlink> need not be suspended 2476 to call this function. 2477 <p/> 2478 The <functionlink id="GetLineNumberTable"></functionlink> 2479 function can be used to map locations to line numbers. Note that 2480 this mapping can be done lazily. 2481 </description> 2482 <origin>jvmpi</origin> 2483 <capabilities> 2484 </capabilities> 2485 <parameters> 2486 <param id="thread"> 2487 <jthread null="current"/> 2488 <description> 2489 Fetch the stack trace of this thread. 2490 </description> 2491 </param> 2492 <param id="start_depth"> 2493 <jint/> 2494 <description> 2495 Begin retrieving frames at this depth. 2496 If non-negative, count from the current frame, 2497 the first frame retrieved is at depth <code>start_depth</code>. 2498 For example, if zero, start from the current frame; if one, start from the 2499 caller of the current frame; if two, start from the caller of the 2500 caller of the current frame; and so on. 2501 If negative, count from below the oldest frame, 2502 the first frame retrieved is at depth <i>stackDepth</i><code> + start_depth</code>, 2503 where <i>stackDepth</i> is the count of frames on the stack. 2504 For example, if negative one, only the oldest frame is retrieved; 2505 if negative two, start from the frame called by the oldest frame. 2506 </description> 2507 </param> 2508 <param id="max_frame_count"> 2509 <jint min="0"/> 2510 <description> 2511 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve. 2512 </description> 2513 </param> 2514 <param id="frame_buffer"> 2515 <outbuf incount="max_frame_count" outcount="count_ptr"> 2516 <struct>jvmtiFrameInfo</struct> 2517 </outbuf> 2518 <description> 2519 On return, this agent allocated buffer is filled 2520 with stack frame information. 2521 </description> 2522 </param> 2523 <param id="count_ptr"> 2524 <outptr><jint/></outptr> 2525 <description> 2526 On return, points to the number of records filled in. 2527 For non-negative <code>start_depth</code>, this will be 2528 min(<code>max_frame_count</code>, <i>stackDepth</i><code> - start_depth</code>). 2529 For negative <code>start_depth</code>, this will be 2530 min(<code>max_frame_count</code>, <code>-start_depth</code>). 2531 </description> 2532 </param> 2533 </parameters> 2534 <errors> 2535 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 2536 <paramlink id="start_depth"/> is positive and greater than or equal to <i>stackDepth</i>. 2537 Or <paramlink id="start_depth"/> is negative and less than <i>-stackDepth</i>. 2538 </error> 2539 </errors> 2540 </function> 2541 2542 2543 <function id="GetAllStackTraces" num="100"> 2544 <synopsis>Get All Stack Traces</synopsis> 2545 <description> 2546 Get information about the stacks of all live threads 2547 (including <internallink id="RunAgentThread">agent threads</internallink>). 2548 If <paramlink id="max_frame_count"/> is less than the depth of a stack, 2549 the <paramlink id="max_frame_count"/> topmost frames are returned for that thread, 2550 otherwise the entire stack is returned. 2551 The topmost frames, those most recently invoked, are at the beginning of the returned buffer. 2552 <p/> 2553 All stacks are collected simultaneously, that is, no changes will occur to the 2554 thread state or stacks between the sampling of one thread and the next. 2555 The threads need not be suspended. 2556 2557 <example> 2558jvmtiStackInfo *stack_info; 2559jint thread_count; 2560int ti; 2561jvmtiError err; 2562 2563err = (*jvmti)->GetAllStackTraces(jvmti, MAX_FRAMES, &stack_info, &thread_count); 2564if (err != JVMTI_ERROR_NONE) { 2565 ... 2566} 2567for (ti = 0; ti < thread_count; ++ti) { 2568 jvmtiStackInfo *infop = &stack_info[ti]; 2569 jthread thread = infop->thread; 2570 jint state = infop->state; 2571 jvmtiFrameInfo *frames = infop->frame_buffer; 2572 int fi; 2573 2574 myThreadAndStatePrinter(thread, state); 2575 for (fi = 0; fi < infop->frame_count; fi++) { 2576 myFramePrinter(frames[fi].method, frames[fi].location); 2577 } 2578} 2579/* this one Deallocate call frees all data allocated by GetAllStackTraces */ 2580err = (*jvmti)->Deallocate(jvmti, stack_info); 2581 </example> 2582 <todo> 2583 check example code. 2584 </todo> 2585 2586 </description> 2587 <origin>new</origin> 2588 <capabilities> 2589 </capabilities> 2590 <parameters> 2591 <param id="max_frame_count"> 2592 <jint min="0"/> 2593 <description> 2594 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread. 2595 </description> 2596 </param> 2597 <param id="stack_info_ptr"> 2598 <allocbuf> 2599 <struct>jvmtiStackInfo</struct> 2600 </allocbuf> 2601 <description> 2602 On return, this buffer is filled 2603 with stack information for each thread. 2604 The number of <datalink id="jvmtiStackInfo"/> records is determined 2605 by <paramlink id="thread_count_ptr"/>. 2606 <p/> 2607 Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/> 2608 buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>. 2609 These buffers must not be separately deallocated. 2610 </description> 2611 </param> 2612 <param id="thread_count_ptr"> 2613 <outptr><jint/></outptr> 2614 <description> 2615 The number of threads traced. 2616 </description> 2617 </param> 2618 </parameters> 2619 <errors> 2620 </errors> 2621 </function> 2622 2623 <function id="GetThreadListStackTraces" num="101"> 2624 <synopsis>Get Thread List Stack Traces</synopsis> 2625 <description> 2626 Get information about the stacks of the supplied threads. 2627 If <paramlink id="max_frame_count"/> is less than the depth of a stack, 2628 the <paramlink id="max_frame_count"/> topmost frames are returned for that thread, 2629 otherwise the entire stack is returned. 2630 The topmost frames, those most recently invoked, are at the beginning of the returned buffer. 2631 <p/> 2632 All stacks are collected simultaneously, that is, no changes will occur to the 2633 thread state or stacks between the sampling one thread and the next. 2634 The threads need not be suspended. 2635 <p/> 2636 If a thread has not yet started or terminates before the stack information is collected, 2637 a zero length stack (<datalink id="jvmtiStackInfo.frame_count"/> will be zero) 2638 will be returned and the thread <datalink id="jvmtiStackInfo.state"/> can be checked. 2639 <p/> 2640 See the example for the similar function 2641 <functionlink id="GetAllStackTraces"/>. 2642 </description> 2643 <origin>new</origin> 2644 <capabilities> 2645 </capabilities> 2646 <parameters> 2647 <param id="thread_count"> 2648 <jint min="0"/> 2649 <description> 2650 The number of threads to trace. 2651 </description> 2652 </param> 2653 <param id="thread_list"> 2654 <inbuf incount="thread_count"><jthread/></inbuf> 2655 <description> 2656 The list of threads to trace. 2657 </description> 2658 </param> 2659 <param id="max_frame_count"> 2660 <jint min="0"/> 2661 <description> 2662 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread. 2663 </description> 2664 </param> 2665 <param id="stack_info_ptr"> 2666 <allocbuf outcount="thread_count"> 2667 <struct>jvmtiStackInfo</struct> 2668 </allocbuf> 2669 <description> 2670 On return, this buffer is filled 2671 with stack information for each thread. 2672 The number of <datalink id="jvmtiStackInfo"/> records is determined 2673 by <paramlink id="thread_count"/>. 2674 <p/> 2675 Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/> 2676 buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>. 2677 These buffers must not be separately deallocated. 2678 </description> 2679 </param> 2680 </parameters> 2681 <errors> 2682 <error id="JVMTI_ERROR_INVALID_THREAD"> 2683 An element in <paramlink id="thread_list"/> is not a thread object. 2684 </error> 2685 </errors> 2686 </function> 2687 2688 <elide> 2689 <function id="AsyncGetStackTrace" num="1000"> 2690 <synopsis>Get Stack Trace--Asynchronous</synopsis> 2691 <description> 2692 Get information about the entire stack of a thread (or a sub-section of it). 2693 This is the asynchronous version of <functionlink id="GetStackTrace"></functionlink> 2694 and is reentrant and safe to call 2695 from asynchronous signal handlers. 2696 The stack trace is returned only for the calling thread. 2697 <p/> 2698 The <functionlink id="GetLineNumberTable"></functionlink> 2699 function can be used to map locations to line numbers. Note that 2700 this mapping can be done lazily. 2701 </description> 2702 <origin>jvmpi</origin> 2703 <capabilities> 2704 <required id="can_get_async_stack_trace"></required> 2705 <capability id="can_show_JVM_spec_async_frames"> 2706 If <code>false</code>, 2707 <paramlink id="use_java_stack"></paramlink> 2708 must be <code>false</code>. 2709 </capability> 2710 </capabilities> 2711 <parameters> 2712 <param id="use_java_stack"> 2713 <jboolean/> 2714 <description> 2715 Return the stack showing <vmspec/> 2716 model of the stack; 2717 otherwise, show the internal representation of the stack with 2718 inlined and optimized methods missing. If the virtual machine 2719 is using the <i>Java Virtual Machine Specification</i> stack model 2720 internally, this flag is ignored. 2721 </description> 2722 </param> 2723 <param id="max_count"> 2724 <jint min="0"/> 2725 <description> 2726 The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve. 2727 Retrieve this many unless the stack depth is less than <code>max_count</code>. 2728 </description> 2729 </param> 2730 <param id="frame_buffer"> 2731 <outbuf incount="max_count" outcount="count_ptr"> 2732 <struct>jvmtiFrameInfo</struct> 2733 <nullok>this information is not returned</nullok> 2734 </outbuf> 2735 <description> 2736 The agent passes in a buffer 2737 large enough to hold <code>max_count</code> records of 2738 <datalink id="jvmtiFrameInfo"></datalink>. This buffer must be 2739 pre-allocated by the agent. 2740 </description> 2741 </param> 2742 <param id="count_ptr"> 2743 <outptr><jint/></outptr> 2744 <description> 2745 On return, points to the number of records filled in.. 2746 </description> 2747 </param> 2748 </parameters> 2749 <errors> 2750 <error id="JVMTI_ERROR_UNATTACHED_THREAD"> 2751 The thread being used to call this function is not attached 2752 to the virtual machine. Calls must be made from attached threads. 2753 </error> 2754 </errors> 2755 </function> 2756 </elide> 2757 2758 <function id="GetFrameCount" num="16"> 2759 <synopsis>Get Frame Count</synopsis> 2760 <description> 2761 Get the number of frames currently in the specified thread's call stack. 2762 <p/> 2763 If this function is called for a thread actively executing bytecodes (for example, 2764 not the current thread and not suspended), the information returned is transient. 2765 </description> 2766 <origin>jvmdi</origin> 2767 <capabilities> 2768 </capabilities> 2769 <parameters> 2770 <param id="thread"> 2771 <jthread null="current"/> 2772 <description> 2773 The thread to query. 2774 </description> 2775 </param> 2776 <param id="count_ptr"> 2777 <outptr><jint/></outptr> 2778 <description> 2779 On return, points to the number of frames in the call stack. 2780 </description> 2781 </param> 2782 </parameters> 2783 <errors> 2784 </errors> 2785 </function> 2786 2787 <function id="PopFrame" num="80"> 2788 <synopsis>Pop Frame</synopsis> 2789 <description> 2790 Pop the current frame of <code>thread</code>'s stack. 2791 Popping a frame takes you to the previous frame. 2792 When the thread is resumed, the execution 2793 state of the thread is reset to the state 2794 immediately before the called method was invoked. 2795 That is (using <vmspec/> terminology): 2796 <ul> 2797 <li>the current frame is discarded as the previous frame becomes the current one</li> 2798 <li>the operand stack is restored--the argument values are added back 2799 and if the invoke was not <code>invokestatic</code>, 2800 <code>objectref</code> is added back as well</li> 2801 <li>the Java virtual machine PC is restored to the opcode 2802 of the invoke instruction</li> 2803 </ul> 2804 Note however, that any changes to the arguments, which 2805 occurred in the called method, remain; 2806 when execution continues, the first instruction to 2807 execute will be the invoke. 2808 <p/> 2809 Between calling <code>PopFrame</code> and resuming the 2810 thread the state of the stack is undefined. 2811 To pop frames beyond the first, 2812 these three steps must be repeated: 2813 <ul> 2814 <li>suspend the thread via an event (step, breakpoint, ...)</li> 2815 <li>call <code>PopFrame</code></li> 2816 <li>resume the thread</li> 2817 </ul> 2818 <p/> 2819 A lock acquired by calling the called method 2820 (if it is a <code>synchronized</code> method) 2821 and locks acquired by entering <code>synchronized</code> 2822 blocks within the called method are released. 2823 Note: this does not apply to native locks or 2824 <code>java.util.concurrent.locks</code> locks. 2825 <p/> 2826 Finally blocks are not executed. 2827 <p/> 2828 Changes to global state are not addressed and thus remain changed. 2829 <p/> 2830 The specified thread must be suspended (which implies it cannot be the current thread). 2831 <p/> 2832 Both the called method and calling method must be non-native Java programming 2833 language methods. 2834 <p/> 2835 No <jvmti/> events are generated by this function. 2836 </description> 2837 <origin>jvmdi</origin> 2838 <capabilities> 2839 <required id="can_pop_frame"></required> 2840 </capabilities> 2841 <parameters> 2842 <param id="thread"> 2843 <jthread/> 2844 <description> 2845 The thread whose current frame is to be popped. 2846 </description> 2847 </param> 2848 </parameters> 2849 <errors> 2850 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 2851 Called or calling method is a native method. 2852 The implementation is unable to pop this frame. 2853 </error> 2854 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED"> 2855 Thread was not suspended. 2856 </error> 2857 <error id="JVMTI_ERROR_NO_MORE_FRAMES"> 2858 There are less than two stack frames on the call stack. 2859 </error> 2860 </errors> 2861 </function> 2862 2863 <function id="GetFrameLocation" num="19"> 2864 <synopsis>Get Frame Location</synopsis> 2865 <description> 2866 <p/> 2867 For a Java programming language frame, return the location of the instruction 2868 currently executing. 2869 </description> 2870 <origin>jvmdiClone</origin> 2871 <capabilities> 2872 </capabilities> 2873 <parameters> 2874 <param id="thread"> 2875 <jthread null="current" frame="frame"/> 2876 <description> 2877 The thread of the frame to query. 2878 </description> 2879 </param> 2880 <param id="depth"> 2881 <jframeID thread="thread"/> 2882 <description> 2883 The depth of the frame to query. 2884 </description> 2885 </param> 2886 <param id="method_ptr"> 2887 <outptr><jmethodID/></outptr> 2888 <description> 2889 On return, points to the method for the current location. 2890 </description> 2891 </param> 2892 <param id="location_ptr"> 2893 <outptr><jlocation/></outptr> 2894 <description> 2895 On return, points to the index of the currently 2896 executing instruction. 2897 Is set to <code>-1</code> if the frame is executing 2898 a native method. 2899 </description> 2900 </param> 2901 </parameters> 2902 <errors> 2903 </errors> 2904 </function> 2905 2906 <function id="NotifyFramePop" num="20"> 2907 <synopsis>Notify Frame Pop</synopsis> 2908 <description> 2909 When the frame that is currently at <paramlink id="depth"></paramlink> 2910 is popped from the stack, generate a 2911 <eventlink id="FramePop"></eventlink> event. See the 2912 <eventlink id="FramePop"></eventlink> event for details. 2913 Only frames corresponding to non-native Java programming language 2914 methods can receive notification. 2915 <p/> 2916 The specified thread must either be the current thread 2917 or the thread must be suspended. 2918 </description> 2919 <origin>jvmdi</origin> 2920 <capabilities> 2921 <required id="can_generate_frame_pop_events"></required> 2922 </capabilities> 2923 <parameters> 2924 <param id="thread"> 2925 <jthread null="current" frame="depth"/> 2926 <description> 2927 The thread of the frame for which the frame pop event will be generated. 2928 </description> 2929 </param> 2930 <param id="depth"> 2931 <jframeID thread="thread"/> 2932 <description> 2933 The depth of the frame for which the frame pop event will be generated. 2934 </description> 2935 </param> 2936 </parameters> 2937 <errors> 2938 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 2939 The frame at <code>depth</code> is executing a 2940 native method. 2941 </error> 2942 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED"> 2943 Thread was not suspended and was not the current thread. 2944 </error> 2945 </errors> 2946 </function> 2947 2948 </category> 2949 2950 <category id="ForceEarlyReturn" label="Force Early Return"> 2951 <intro> 2952 These functions allow an agent to force a method 2953 to return at any point during its execution. 2954 The method which will return early is referred to as the <i>called method</i>. 2955 The called method is the current method 2956 (as defined by 2957 <vmspec chapter="3.6"/>) 2958 for the specified thread at 2959 the time the function is called. 2960 <p/> 2961 The specified thread must be suspended or must be the current thread. 2962 The return occurs when execution of Java programming 2963 language code is resumed on this thread. 2964 Between calling one of these functions and resumption 2965 of thread execution, the state of the stack is undefined. 2966 <p/> 2967 No further instructions are executed in the called method. 2968 Specifically, finally blocks are not executed. 2969 Note: this can cause inconsistent states in the application. 2970 <p/> 2971 A lock acquired by calling the called method 2972 (if it is a <code>synchronized</code> method) 2973 and locks acquired by entering <code>synchronized</code> 2974 blocks within the called method are released. 2975 Note: this does not apply to native locks or 2976 <code>java.util.concurrent.locks</code> locks. 2977 <p/> 2978 Events, such as <eventlink id="MethodExit"></eventlink>, 2979 are generated as they would be in a normal return. 2980 <p/> 2981 The called method must be a non-native Java programming 2982 language method. 2983 Forcing return on a thread with only one frame on the 2984 stack causes the thread to exit when resumed. 2985 </intro> 2986 2987 <function id="ForceEarlyReturnObject" num="81" since="1.1"> 2988 <synopsis>Force Early Return - Object</synopsis> 2989 <description> 2990 This function can be used to return from a method whose 2991 result type is <code>Object</code> 2992 or a subclass of <code>Object</code>. 2993 </description> 2994 <origin>new</origin> 2995 <capabilities> 2996 <required id="can_force_early_return"></required> 2997 </capabilities> 2998 <parameters> 2999 <param id="thread"> 3000 <jthread null="current"/> 3001 <description> 3002 The thread whose current frame is to return early. 3003 </description> 3004 </param> 3005 <param id="value"> 3006 <jobject/> 3007 <description> 3008 The return value for the called frame. 3009 An object or <code>NULL</code>. 3010 </description> 3011 </param> 3012 </parameters> 3013 <errors> 3014 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 3015 Attempted to return early from a frame 3016 corresponding to a native method. 3017 Or the implementation is unable to provide 3018 this functionality on this frame. 3019 </error> 3020 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 3021 The result type of the called method is not 3022 <code>Object</code> or a subclass of <code>Object</code>. 3023 </error> 3024 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 3025 The supplied <paramlink id="value"/> is not compatible with the 3026 result type of the called method. 3027 </error> 3028 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED"> 3029 Thread was not the current thread and was not suspended. 3030 </error> 3031 <error id="JVMTI_ERROR_NO_MORE_FRAMES"> 3032 There are no more frames on the call stack. 3033 </error> 3034 </errors> 3035 </function> 3036 3037 <function id="ForceEarlyReturnInt" num="82" since="1.1"> 3038 <synopsis>Force Early Return - Int</synopsis> 3039 <description> 3040 This function can be used to return from a method whose 3041 result type is <code>int</code>, <code>short</code>, 3042 <code>char</code>, <code>byte</code>, or 3043 <code>boolean</code>. 3044 </description> 3045 <origin>new</origin> 3046 <capabilities> 3047 <required id="can_force_early_return"></required> 3048 </capabilities> 3049 <parameters> 3050 <param id="thread"> 3051 <jthread null="current"/> 3052 <description> 3053 The thread whose current frame is to return early. 3054 </description> 3055 </param> 3056 <param id="value"> 3057 <jint/> 3058 <description> 3059 The return value for the called frame. 3060 </description> 3061 </param> 3062 </parameters> 3063 <errors> 3064 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 3065 Attempted to return early from a frame 3066 corresponding to a native method. 3067 Or the implementation is unable to provide 3068 this functionality on this frame. 3069 </error> 3070 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 3071 The result type of the called method is not 3072 <code>int</code>, <code>short</code>, 3073 <code>char</code>, <code>byte</code>, or 3074 <code>boolean</code>. 3075 </error> 3076 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED"> 3077 Thread was not the current thread and was not suspended. 3078 </error> 3079 <error id="JVMTI_ERROR_NO_MORE_FRAMES"> 3080 There are no frames on the call stack. 3081 </error> 3082 </errors> 3083 </function> 3084 3085 <function id="ForceEarlyReturnLong" num="83" since="1.1"> 3086 <synopsis>Force Early Return - Long</synopsis> 3087 <description> 3088 This function can be used to return from a method whose 3089 result type is <code>long</code>. 3090 </description> 3091 <origin>new</origin> 3092 <capabilities> 3093 <required id="can_force_early_return"></required> 3094 </capabilities> 3095 <parameters> 3096 <param id="thread"> 3097 <jthread null="current"/> 3098 <description> 3099 The thread whose current frame is to return early. 3100 </description> 3101 </param> 3102 <param id="value"> 3103 <jlong/> 3104 <description> 3105 The return value for the called frame. 3106 </description> 3107 </param> 3108 </parameters> 3109 <errors> 3110 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 3111 Attempted to return early from a frame 3112 corresponding to a native method. 3113 Or the implementation is unable to provide 3114 this functionality on this frame. 3115 </error> 3116 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 3117 The result type of the called method is not <code>long</code>. 3118 </error> 3119 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED"> 3120 Thread was not the current thread and was not suspended. 3121 </error> 3122 <error id="JVMTI_ERROR_NO_MORE_FRAMES"> 3123 There are no frames on the call stack. 3124 </error> 3125 </errors> 3126 </function> 3127 3128 <function id="ForceEarlyReturnFloat" num="84" since="1.1"> 3129 <synopsis>Force Early Return - Float</synopsis> 3130 <description> 3131 This function can be used to return from a method whose 3132 result type is <code>float</code>. 3133 </description> 3134 <origin>new</origin> 3135 <capabilities> 3136 <required id="can_force_early_return"></required> 3137 </capabilities> 3138 <parameters> 3139 <param id="thread"> 3140 <jthread null="current"/> 3141 <description> 3142 The thread whose current frame is to return early. 3143 </description> 3144 </param> 3145 <param id="value"> 3146 <jfloat/> 3147 <description> 3148 The return value for the called frame. 3149 </description> 3150 </param> 3151 </parameters> 3152 <errors> 3153 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 3154 Attempted to return early from a frame 3155 corresponding to a native method. 3156 Or the implementation is unable to provide 3157 this functionality on this frame. 3158 </error> 3159 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 3160 The result type of the called method is not <code>float</code>. 3161 </error> 3162 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED"> 3163 Thread was not the current thread and was not suspended. 3164 </error> 3165 <error id="JVMTI_ERROR_NO_MORE_FRAMES"> 3166 There are no frames on the call stack. 3167 </error> 3168 </errors> 3169 </function> 3170 3171 <function id="ForceEarlyReturnDouble" num="85" since="1.1"> 3172 <synopsis>Force Early Return - Double</synopsis> 3173 <description> 3174 This function can be used to return from a method whose 3175 result type is <code>double</code>. 3176 </description> 3177 <origin>new</origin> 3178 <capabilities> 3179 <required id="can_force_early_return"></required> 3180 </capabilities> 3181 <parameters> 3182 <param id="thread"> 3183 <jthread null="current"/> 3184 <description> 3185 The thread whose current frame is to return early. 3186 </description> 3187 </param> 3188 <param id="value"> 3189 <jdouble/> 3190 <description> 3191 The return value for the called frame. 3192 </description> 3193 </param> 3194 </parameters> 3195 <errors> 3196 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 3197 Attempted to return early from a frame corresponding to a native method. 3198 Or the implementation is unable to provide this functionality on this frame. 3199 </error> 3200 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 3201 The result type of the called method is not <code>double</code>. 3202 </error> 3203 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED"> 3204 Thread was not the current thread and was not suspended. 3205 </error> 3206 <error id="JVMTI_ERROR_NO_MORE_FRAMES"> 3207 There are no frames on the call stack. 3208 </error> 3209 </errors> 3210 </function> 3211 3212 <function id="ForceEarlyReturnVoid" num="86" since="1.1"> 3213 <synopsis>Force Early Return - Void</synopsis> 3214 <description> 3215 This function can be used to return from a method with no result type. 3216 That is, the called method must be declared <code>void</code>. 3217 </description> 3218 <origin>new</origin> 3219 <capabilities> 3220 <required id="can_force_early_return"></required> 3221 </capabilities> 3222 <parameters> 3223 <param id="thread"> 3224 <jthread null="current"/> 3225 <description> 3226 The thread whose current frame is to return early. 3227 </description> 3228 </param> 3229 </parameters> 3230 <errors> 3231 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 3232 Attempted to return early from a frame 3233 corresponding to a native method. 3234 Or the implementation is unable to provide 3235 this functionality on this frame. 3236 </error> 3237 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 3238 The called method has a result type. 3239 </error> 3240 <error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED"> 3241 Thread was not the current thread and was not suspended. 3242 </error> 3243 <error id="JVMTI_ERROR_NO_MORE_FRAMES"> 3244 There are no frames on the call stack. 3245 </error> 3246 </errors> 3247 </function> 3248 3249 </category> 3250 3251 <category id="Heap" label="Heap"> 3252 <intro> 3253 These functions are used to analyze the heap. 3254 Functionality includes the ability to view the objects in the 3255 heap and to tag these objects. 3256 </intro> 3257 3258 <intro id="objectTags" label="Object Tags"> 3259 A <i>tag</i> is a value associated with an object. 3260 Tags are explicitly set by the agent using the 3261 <functionlink id="SetTag"></functionlink> function or by 3262 callback functions such as <functionlink id="jvmtiHeapIterationCallback"/>. 3263 <p/> 3264 Tags are local to the environment; that is, the tags of one 3265 environment are not visible in another. 3266 <p/> 3267 Tags are <code>jlong</code> values which can be used 3268 simply to mark an object or to store a pointer to more detailed 3269 information. Objects which have not been tagged have a 3270 tag of zero. 3271 Setting a tag to zero makes the object untagged. 3272 </intro> 3273 3274 <intro id="heapCallbacks" label="Heap Callback Functions"> 3275 Heap functions which iterate through the heap and recursively 3276 follow object references use agent supplied callback functions 3277 to deliver the information. 3278 <p/> 3279 These heap callback functions must adhere to the following restrictions -- 3280 These callbacks must not use JNI functions. 3281 These callbacks must not use <jvmti/> functions except 3282 <i>callback safe</i> functions which 3283 specifically allow such use (see the raw monitor, memory management, 3284 and environment local storage functions). 3285 <p/> 3286 An implementation may invoke a callback on an internal thread or 3287 the thread which called the iteration function. 3288 Heap callbacks are single threaded -- no more than one callback will 3289 be invoked at a time. 3290 <p/> 3291 The Heap Filter Flags can be used to prevent reporting 3292 based on the tag status of an object or its class. 3293 If no flags are set (the <code>jint</code> is zero), objects 3294 will not be filtered out. 3295 3296 <constants id="jvmtiHeapFilter" label="Heap Filter Flags" kind="bits"> 3297 <constant id="JVMTI_HEAP_FILTER_TAGGED" num="0x4"> 3298 Filter out tagged objects. Objects which are tagged are not included. 3299 </constant> 3300 <constant id="JVMTI_HEAP_FILTER_UNTAGGED" num="0x8"> 3301 Filter out untagged objects. Objects which are not tagged are not included. 3302 </constant> 3303 <constant id="JVMTI_HEAP_FILTER_CLASS_TAGGED" num="0x10"> 3304 Filter out objects with tagged classes. Objects whose class is tagged are not included. 3305 </constant> 3306 <constant id="JVMTI_HEAP_FILTER_CLASS_UNTAGGED" num="0x20"> 3307 Filter out objects with untagged classes. Objects whose class is not tagged are not included. 3308 </constant> 3309 </constants> 3310 3311 <p/> 3312 The Heap Visit Control Flags are returned by the heap callbacks 3313 and can be used to abort the iteration. For the 3314 <functionlink id="jvmtiHeapReferenceCallback">Heap 3315 Reference Callback</functionlink>, it can also be used 3316 to prune the graph of traversed references 3317 (<code>JVMTI_VISIT_OBJECTS</code> is not set). 3318 3319 <constants id="jvmtiHeapVisitControl" 3320 label="Heap Visit Control Flags" 3321 kind="bits" 3322 since="1.1"> 3323 <constant id="JVMTI_VISIT_OBJECTS" num="0x100"> 3324 If we are visiting an object and if this callback 3325 was initiated by <functionlink id="FollowReferences"/>, 3326 traverse the references of this object. 3327 Otherwise ignored. 3328 </constant> 3329 <constant id="JVMTI_VISIT_ABORT" num="0x8000"> 3330 Abort the iteration. Ignore all other bits. 3331 </constant> 3332 </constants> 3333 3334 <p/> 3335 The Heap Reference Enumeration is provided by the 3336 <functionlink id="jvmtiHeapReferenceCallback">Heap 3337 Reference Callback</functionlink> and 3338 <functionlink id="jvmtiPrimitiveFieldCallback">Primitive Field 3339 Callback</functionlink> to 3340 describe the kind of reference 3341 being reported. 3342 3343 <constants id="jvmtiHeapReferenceKind" 3344 label="Heap Reference Enumeration" 3345 kind="enum" 3346 since="1.1"> 3347 <constant id="JVMTI_HEAP_REFERENCE_CLASS" num="1"> 3348 Reference from an object to its class. 3349 </constant> 3350 <constant id="JVMTI_HEAP_REFERENCE_FIELD" num="2"> 3351 Reference from an object to the value of one of its instance fields. 3352 </constant> 3353 <constant id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT" num="3"> 3354 Reference from an array to one of its elements. 3355 </constant> 3356 <constant id="JVMTI_HEAP_REFERENCE_CLASS_LOADER" num="4"> 3357 Reference from a class to its class loader. 3358 </constant> 3359 <constant id="JVMTI_HEAP_REFERENCE_SIGNERS" num="5"> 3360 Reference from a class to its signers array. 3361 </constant> 3362 <constant id="JVMTI_HEAP_REFERENCE_PROTECTION_DOMAIN" num="6"> 3363 Reference from a class to its protection domain. 3364 </constant> 3365 <constant id="JVMTI_HEAP_REFERENCE_INTERFACE" num="7"> 3366 Reference from a class to one of its interfaces. 3367 Note: interfaces are defined via a constant pool reference, 3368 so the referenced interfaces may also be reported with a 3369 <code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind. 3370 </constant> 3371 <constant id="JVMTI_HEAP_REFERENCE_STATIC_FIELD" num="8"> 3372 Reference from a class to the value of one of its static fields. 3373 </constant> 3374 <constant id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL" num="9"> 3375 Reference from a class to a resolved entry in the constant pool. 3376 </constant> 3377 <constant id="JVMTI_HEAP_REFERENCE_SUPERCLASS" num="10"> 3378 Reference from a class to its superclass. 3379 A callback is not sent if the superclass is <code>java.lang.Object</code>. 3380 Note: loaded classes define superclasses via a constant pool 3381 reference, so the referenced superclass may also be reported with 3382 a <code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind. 3383 </constant> 3384 <constant id="JVMTI_HEAP_REFERENCE_JNI_GLOBAL" num="21"> 3385 Heap root reference: JNI global reference. 3386 </constant> 3387 <constant id="JVMTI_HEAP_REFERENCE_SYSTEM_CLASS" num="22"> 3388 Heap root reference: System class. 3389 </constant> 3390 <constant id="JVMTI_HEAP_REFERENCE_MONITOR" num="23"> 3391 Heap root reference: monitor. 3392 </constant> 3393 <constant id="JVMTI_HEAP_REFERENCE_STACK_LOCAL" num="24"> 3394 Heap root reference: local variable on the stack. 3395 </constant> 3396 <constant id="JVMTI_HEAP_REFERENCE_JNI_LOCAL" num="25"> 3397 Heap root reference: JNI local reference. 3398 </constant> 3399 <constant id="JVMTI_HEAP_REFERENCE_THREAD" num="26"> 3400 Heap root reference: Thread. 3401 </constant> 3402 <constant id="JVMTI_HEAP_REFERENCE_OTHER" num="27"> 3403 Heap root reference: other heap root reference. 3404 </constant> 3405 </constants> 3406 3407 <p/> 3408 Definitions for the single character type descriptors of 3409 primitive types. 3410 3411 <constants id="jvmtiPrimitiveType" 3412 label="Primitive Type Enumeration" 3413 kind="enum" 3414 since="1.1"> 3415 <constant id="JVMTI_PRIMITIVE_TYPE_BOOLEAN" num="90"> 3416 'Z' - Java programming language <code>boolean</code> - JNI <code>jboolean</code> 3417 </constant> 3418 <constant id="JVMTI_PRIMITIVE_TYPE_BYTE" num="66"> 3419 'B' - Java programming language <code>byte</code> - JNI <code>jbyte</code> 3420 </constant> 3421 <constant id="JVMTI_PRIMITIVE_TYPE_CHAR" num="67"> 3422 'C' - Java programming language <code>char</code> - JNI <code>jchar</code> 3423 </constant> 3424 <constant id="JVMTI_PRIMITIVE_TYPE_SHORT" num="83"> 3425 'S' - Java programming language <code>short</code> - JNI <code>jshort</code> 3426 </constant> 3427 <constant id="JVMTI_PRIMITIVE_TYPE_INT" num="73"> 3428 'I' - Java programming language <code>int</code> - JNI <code>jint</code> 3429 </constant> 3430 <constant id="JVMTI_PRIMITIVE_TYPE_LONG" num="74"> 3431 'J' - Java programming language <code>long</code> - JNI <code>jlong</code> 3432 </constant> 3433 <constant id="JVMTI_PRIMITIVE_TYPE_FLOAT" num="70"> 3434 'F' - Java programming language <code>float</code> - JNI <code>jfloat</code> 3435 </constant> 3436 <constant id="JVMTI_PRIMITIVE_TYPE_DOUBLE" num="68"> 3437 'D' - Java programming language <code>double</code> - JNI <code>jdouble</code> 3438 </constant> 3439 </constants> 3440 </intro> 3441 3442 <typedef id="jvmtiHeapReferenceInfoField" 3443 label="Reference information structure for Field references" 3444 since="1.1"> 3445 <description> 3446 Reference information returned for 3447 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> and 3448 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references. 3449 </description> 3450 <field id="index"> 3451 <jint/> 3452 <description> 3453 For <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>, the 3454 referrer object is not a class or an inteface. 3455 In this case, <code>index</code> is the index of the field 3456 in the class of the referrer object. 3457 This class is referred to below as <i>C</i>. 3458 <p/> 3459 For <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>, 3460 the referrer object is a class (referred to below as <i>C</i>) 3461 or an interface (referred to below as <i>I</i>). 3462 In this case, <code>index</code> is the index of the field in 3463 that class or interface. 3464 <p/> 3465 If the referrer object is not an interface, then the field 3466 indices are determined as follows: 3467 <ul> 3468 <li>make a list of all the fields in <i>C</i> and its 3469 superclasses, starting with all the fields in 3470 <code>java.lang.Object</code> and ending with all the 3471 fields in <i>C</i>.</li> 3472 <li>Within this list, put 3473 the fields for a given class in the order returned by 3474 <functionlink id="GetClassFields"/>.</li> 3475 <li>Assign the fields in this list indices 3476 <i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i> 3477 is the count of the fields in all the interfaces 3478 implemented by <i>C</i>. 3479 Note that <i>C</i> implements all interfaces 3480 directly implemented by its superclasses; as well 3481 as all superinterfaces of these interfaces.</li> 3482 </ul> 3483 If the referrer object is an interface, then the field 3484 indices are determined as follows: 3485 <ul> 3486 <li>make a list of the fields directly declared in 3487 <i>I</i>.</li> 3488 <li>Within this list, put 3489 the fields in the order returned by 3490 <functionlink id="GetClassFields"/>.</li> 3491 <li>Assign the fields in this list indices 3492 <i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i> 3493 is the count of the fields in all the superinterfaces 3494 of <i>I</i>.</li> 3495 </ul> 3496 All fields are included in this computation, regardless of 3497 field modifier (static, public, private, etc). 3498 <p/> 3499 For example, given the following classes and interfaces: 3500 <example> 3501interface I0 { 3502 int p = 0; 3503} 3504 3505interface I1 extends I0 { 3506 int x = 1; 3507} 3508 3509interface I2 extends I0 { 3510 int y = 2; 3511} 3512 3513class C1 implements I1 { 3514 public static int a = 3; 3515 private int b = 4; 3516} 3517 3518class C2 extends C1 implements I2 { 3519 static int q = 5; 3520 final int r = 6; 3521} 3522 </example> 3523 Assume that <functionlink id="GetClassFields"/> called on 3524 <code>C1</code> returns the fields of <code>C1</code> in the 3525 order: a, b; and that the fields of <code>C2</code> are 3526 returned in the order: q, r. 3527 An instance of class <code>C1</code> will have the 3528 following field indices: 3529 <dl><dd><table> 3530 <tr> 3531 <td> 3532 a 3533 </td> 3534 <td> 3535 2 3536 </td> 3537 <td align="left"> 3538 The count of the fields in the interfaces 3539 implemented by <code>C1</code> is two (<i>n</i>=2): 3540 <code>p</code> of <code>I0</code> 3541 and <code>x</code> of <code>I1</code>. 3542 </td> 3543 </tr> 3544 <tr> 3545 <td> 3546 b 3547 </td> 3548 <td> 3549 3 3550 </td> 3551 <td align="left"> 3552 the subsequent index. 3553 </td> 3554 </tr> 3555 </table></dd></dl> 3556 The class <code>C1</code> will have the same field indices. 3557 <p/> 3558 An instance of class <code>C2</code> will have the 3559 following field indices: 3560 <dl><dd><table> 3561 <tr> 3562 <td> 3563 a 3564 </td> 3565 <td> 3566 3 3567 </td> 3568 <td align="left"> 3569 The count of the fields in the interfaces 3570 implemented by <code>C2</code> is three (<i>n</i>=3): 3571 <code>p</code> of <code>I0</code>, 3572 <code>x</code> of <code>I1</code> and <code>y</code> of <code>I2</code> 3573 (an interface of <code>C2</code>). Note that the field <code>p</code> 3574 of <code>I0</code> is only included once. 3575 </td> 3576 </tr> 3577 <tr> 3578 <td> 3579 b 3580 </td> 3581 <td> 3582 4 3583 </td> 3584 <td align="left"> 3585 the subsequent index to "a". 3586 </td> 3587 </tr> 3588 <tr> 3589 <td> 3590 q 3591 </td> 3592 <td> 3593 5 3594 </td> 3595 <td align="left"> 3596 the subsequent index to "b". 3597 </td> 3598 </tr> 3599 <tr> 3600 <td> 3601 r 3602 </td> 3603 <td> 3604 6 3605 </td> 3606 <td align="left"> 3607 the subsequent index to "q". 3608 </td> 3609 </tr> 3610 </table></dd></dl> 3611 The class <code>C2</code> will have the same field indices. 3612 Note that a field may have a different index depending on the 3613 object that is viewing it -- for example field "a" above. 3614 Note also: not all field indices may be visible from the 3615 callbacks, but all indices are shown for illustrative purposes. 3616 <p/> 3617 The interface <code>I1</code> will have the 3618 following field indices: 3619 <dl><dd><table> 3620 <tr> 3621 <td> 3622 x 3623 </td> 3624 <td> 3625 1 3626 </td> 3627 <td align="left"> 3628 The count of the fields in the superinterfaces 3629 of <code>I1</code> is one (<i>n</i>=1): 3630 <code>p</code> of <code>I0</code>. 3631 </td> 3632 </tr> 3633 </table></dd></dl> 3634 </description> 3635 </field> 3636 </typedef> 3637 3638 <typedef id="jvmtiHeapReferenceInfoArray" 3639 label="Reference information structure for Array references" 3640 since="1.1"> 3641 <description> 3642 Reference information returned for 3643 <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references. 3644 </description> 3645 <field id="index"> 3646 <jint/> 3647 <description> 3648 The array index. 3649 </description> 3650 </field> 3651 </typedef> 3652 3653 <typedef id="jvmtiHeapReferenceInfoConstantPool" 3654 label="Reference information structure for Constant Pool references" 3655 since="1.1"> 3656 <description> 3657 Reference information returned for 3658 <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references. 3659 </description> 3660 <field id="index"> 3661 <jint/> 3662 <description> 3663 The index into the constant pool of the class. See the description in 3664 <vmspec chapter="4.4"/>. 3665 </description> 3666 </field> 3667 </typedef> 3668 3669 <typedef id="jvmtiHeapReferenceInfoStackLocal" 3670 label="Reference information structure for Local Variable references" 3671 since="1.1"> 3672 <description> 3673 Reference information returned for 3674 <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references. 3675 </description> 3676 <field id="thread_tag"> 3677 <jlong/> 3678 <description> 3679 The tag of the thread corresponding to this stack, zero if not tagged. 3680 </description> 3681 </field> 3682 <field id="thread_id"> 3683 <jlong/> 3684 <description> 3685 The unique thread ID of the thread corresponding to this stack. 3686 </description> 3687 </field> 3688 <field id="depth"> 3689 <jint/> 3690 <description> 3691 The depth of the frame. 3692 </description> 3693 </field> 3694 <field id="method"> 3695 <jmethodID/> 3696 <description> 3697 The method executing in this frame. 3698 </description> 3699 </field> 3700 <field id="location"> 3701 <jlocation/> 3702 <description> 3703 The currently executing location in this frame. 3704 </description> 3705 </field> 3706 <field id="slot"> 3707 <jint/> 3708 <description> 3709 The slot number of the local variable. 3710 </description> 3711 </field> 3712 </typedef> 3713 3714 <typedef id="jvmtiHeapReferenceInfoJniLocal" 3715 label="Reference information structure for JNI local references" 3716 since="1.1"> 3717 <description> 3718 Reference information returned for 3719 <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references. 3720 </description> 3721 <field id="thread_tag"> 3722 <jlong/> 3723 <description> 3724 The tag of the thread corresponding to this stack, zero if not tagged. 3725 </description> 3726 </field> 3727 <field id="thread_id"> 3728 <jlong/> 3729 <description> 3730 The unique thread ID of the thread corresponding to this stack. 3731 </description> 3732 </field> 3733 <field id="depth"> 3734 <jint/> 3735 <description> 3736 The depth of the frame. 3737 </description> 3738 </field> 3739 <field id="method"> 3740 <jmethodID/> 3741 <description> 3742 The method executing in this frame. 3743 </description> 3744 </field> 3745 </typedef> 3746 3747 <typedef id="jvmtiHeapReferenceInfoReserved" 3748 label="Reference information structure for Other references" 3749 since="1.1"> 3750 <description> 3751 Reference information returned for other references. 3752 </description> 3753 <field id="reserved1"> 3754 <jlong/> 3755 <description> 3756 reserved for future use. 3757 </description> 3758 </field> 3759 <field id="reserved2"> 3760 <jlong/> 3761 <description> 3762 reserved for future use. 3763 </description> 3764 </field> 3765 <field id="reserved3"> 3766 <jlong/> 3767 <description> 3768 reserved for future use. 3769 </description> 3770 </field> 3771 <field id="reserved4"> 3772 <jlong/> 3773 <description> 3774 reserved for future use. 3775 </description> 3776 </field> 3777 <field id="reserved5"> 3778 <jlong/> 3779 <description> 3780 reserved for future use. 3781 </description> 3782 </field> 3783 <field id="reserved6"> 3784 <jlong/> 3785 <description> 3786 reserved for future use. 3787 </description> 3788 </field> 3789 <field id="reserved7"> 3790 <jlong/> 3791 <description> 3792 reserved for future use. 3793 </description> 3794 </field> 3795 <field id="reserved8"> 3796 <jlong/> 3797 <description> 3798 reserved for future use. 3799 </description> 3800 </field> 3801 </typedef> 3802 3803 <uniontypedef id="jvmtiHeapReferenceInfo" 3804 label="Reference information structure" 3805 since="1.1"> 3806 <description> 3807 The information returned about referrers. 3808 Represented as a union of the various kinds of reference information. 3809 </description> 3810 <field id="field"> 3811 <struct>jvmtiHeapReferenceInfoField</struct> 3812 <description> 3813 The referrer information for 3814 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> 3815 and <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references. 3816 </description> 3817 </field> 3818 <field id="array"> 3819 <struct>jvmtiHeapReferenceInfoArray</struct> 3820 <description> 3821 The referrer information for 3822 For <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references. 3823 </description> 3824 </field> 3825 <field id="constant_pool"> 3826 <struct>jvmtiHeapReferenceInfoConstantPool</struct> 3827 <description> 3828 The referrer information for 3829 For <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references. 3830 </description> 3831 </field> 3832 <field id="stack_local"> 3833 <struct>jvmtiHeapReferenceInfoStackLocal</struct> 3834 <description> 3835 The referrer information for 3836 For <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references. 3837 </description> 3838 </field> 3839 <field id="jni_local"> 3840 <struct>jvmtiHeapReferenceInfoJniLocal</struct> 3841 <description> 3842 The referrer information for 3843 For <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references. 3844 </description> 3845 </field> 3846 <field id="other"> 3847 <struct>jvmtiHeapReferenceInfoReserved</struct> 3848 <description> 3849 reserved for future use. 3850 </description> 3851 </field> 3852 </uniontypedef> 3853 3854 <typedef id="jvmtiHeapCallbacks" 3855 label="Heap callback function structure" 3856 since="1.1"> 3857 <field id="heap_iteration_callback"> 3858 <ptrtype> 3859 <struct>jvmtiHeapIterationCallback</struct> 3860 </ptrtype> 3861 <description> 3862 The callback to be called to describe an 3863 object in the heap. Used by the 3864 <functionlink id="IterateThroughHeap"/> function, ignored by the 3865 <functionlink id="FollowReferences"/> function. 3866 </description> 3867 </field> 3868 <field id="heap_reference_callback"> 3869 <ptrtype> 3870 <struct>jvmtiHeapReferenceCallback</struct> 3871 </ptrtype> 3872 <description> 3873 The callback to be called to describe an 3874 object reference. Used by the 3875 <functionlink id="FollowReferences"/> function, ignored by the 3876 <functionlink id="IterateThroughHeap"/> function. 3877 </description> 3878 </field> 3879 <field id="primitive_field_callback"> 3880 <ptrtype> 3881 <struct>jvmtiPrimitiveFieldCallback</struct> 3882 </ptrtype> 3883 <description> 3884 The callback to be called to describe a 3885 primitive field. 3886 </description> 3887 </field> 3888 <field id="array_primitive_value_callback"> 3889 <ptrtype> 3890 <struct>jvmtiArrayPrimitiveValueCallback</struct> 3891 </ptrtype> 3892 <description> 3893 The callback to be called to describe an 3894 array of primitive values. 3895 </description> 3896 </field> 3897 <field id="string_primitive_value_callback"> 3898 <ptrtype> 3899 <struct>jvmtiStringPrimitiveValueCallback</struct> 3900 </ptrtype> 3901 <description> 3902 The callback to be called to describe a String value. 3903 </description> 3904 </field> 3905 <field id="reserved5"> 3906 <ptrtype> 3907 <struct>jvmtiReservedCallback</struct> 3908 </ptrtype> 3909 <description> 3910 Reserved for future use.. 3911 </description> 3912 </field> 3913 <field id="reserved6"> 3914 <ptrtype> 3915 <struct>jvmtiReservedCallback</struct> 3916 </ptrtype> 3917 <description> 3918 Reserved for future use.. 3919 </description> 3920 </field> 3921 <field id="reserved7"> 3922 <ptrtype> 3923 <struct>jvmtiReservedCallback</struct> 3924 </ptrtype> 3925 <description> 3926 Reserved for future use.. 3927 </description> 3928 </field> 3929 <field id="reserved8"> 3930 <ptrtype> 3931 <struct>jvmtiReservedCallback</struct> 3932 </ptrtype> 3933 <description> 3934 Reserved for future use.. 3935 </description> 3936 </field> 3937 <field id="reserved9"> 3938 <ptrtype> 3939 <struct>jvmtiReservedCallback</struct> 3940 </ptrtype> 3941 <description> 3942 Reserved for future use.. 3943 </description> 3944 </field> 3945 <field id="reserved10"> 3946 <ptrtype> 3947 <struct>jvmtiReservedCallback</struct> 3948 </ptrtype> 3949 <description> 3950 Reserved for future use.. 3951 </description> 3952 </field> 3953 <field id="reserved11"> 3954 <ptrtype> 3955 <struct>jvmtiReservedCallback</struct> 3956 </ptrtype> 3957 <description> 3958 Reserved for future use.. 3959 </description> 3960 </field> 3961 <field id="reserved12"> 3962 <ptrtype> 3963 <struct>jvmtiReservedCallback</struct> 3964 </ptrtype> 3965 <description> 3966 Reserved for future use.. 3967 </description> 3968 </field> 3969 <field id="reserved13"> 3970 <ptrtype> 3971 <struct>jvmtiReservedCallback</struct> 3972 </ptrtype> 3973 <description> 3974 Reserved for future use.. 3975 </description> 3976 </field> 3977 <field id="reserved14"> 3978 <ptrtype> 3979 <struct>jvmtiReservedCallback</struct> 3980 </ptrtype> 3981 <description> 3982 Reserved for future use.. 3983 </description> 3984 </field> 3985 <field id="reserved15"> 3986 <ptrtype> 3987 <struct>jvmtiReservedCallback</struct> 3988 </ptrtype> 3989 <description> 3990 Reserved for future use.. 3991 </description> 3992 </field> 3993 </typedef> 3994 3995 3996 <intro> 3997 <rationale> 3998 The heap dumping functionality (below) uses a callback 3999 for each object. While it would seem that a buffered approach 4000 would provide better throughput, tests do 4001 not show this to be the case--possibly due to locality of 4002 memory reference or array access overhead. 4003 </rationale> 4004 4005 <issue> 4006 Still under investigation as to if java.lang.ref references 4007 are reported as a different type of reference. 4008 </issue> 4009 4010 <issue> 4011 Should or can an indication of the cost or relative cost of 4012 these operations be included? 4013 </issue> 4014 4015 </intro> 4016 4017 <callback id="jvmtiHeapIterationCallback" since="1.1"> 4018 <jint/> 4019 <synopsis>Heap Iteration Callback</synopsis> 4020 <description> 4021 Agent supplied callback function. 4022 Describes (but does not pass in) an object in the heap. 4023 <p/> 4024 This function should return a bit vector of the desired 4025 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>. 4026 This will determine if the entire iteration should be aborted 4027 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored). 4028 <p/> 4029 See the <internallink id="heapCallbacks">heap callback 4030 function restrictions</internallink>. 4031 </description> 4032 <parameters> 4033 <param id="class_tag"> 4034 <jlong/> 4035 <description> 4036 The tag of the class of object (zero if the class is not tagged). 4037 If the object represents a runtime class, 4038 the <code>class_tag</code> is the tag 4039 associated with <code>java.lang.Class</code> 4040 (zero if <code>java.lang.Class</code> is not tagged). 4041 </description> 4042 </param> 4043 <param id="size"> 4044 <jlong/> 4045 <description> 4046 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>. 4047 </description> 4048 </param> 4049 <param id="tag_ptr"> 4050 <outptr><jlong/></outptr> 4051 <description> 4052 The object tag value, or zero if the object is not tagged. 4053 To set the tag value to be associated with the object 4054 the agent sets the <code>jlong</code> pointed to by the parameter. 4055 </description> 4056 </param> 4057 <param id="length"> 4058 <jint/> 4059 <description> 4060 If this object is an array, the length of the array. Otherwise negative one (-1). 4061 </description> 4062 </param> 4063 <param id="user_data"> 4064 <outptr><void/></outptr> 4065 <description> 4066 The user supplied data that was passed into the iteration function. 4067 </description> 4068 </param> 4069 </parameters> 4070 </callback> 4071 4072 <callback id="jvmtiHeapReferenceCallback" since="1.1"> 4073 <jint/> 4074 <synopsis>Heap Reference Callback</synopsis> 4075 <description> 4076 Agent supplied callback function. 4077 Describes a reference from an object or the VM (the referrer) to another object 4078 (the referree) or a heap root to a referree. 4079 <p/> 4080 This function should return a bit vector of the desired 4081 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>. 4082 This will determine if the objects referenced by the referree 4083 should be visited or if the entire iteration should be aborted. 4084 <p/> 4085 See the <internallink id="heapCallbacks">heap callback 4086 function restrictions</internallink>. 4087 </description> 4088 <parameters> 4089 <param id="reference_kind"> 4090 <enum>jvmtiHeapReferenceKind</enum> 4091 <description> 4092 The kind of reference. 4093 </description> 4094 </param> 4095 <param id="reference_info"> 4096 <inptr> 4097 <struct>jvmtiHeapReferenceInfo</struct> 4098 </inptr> 4099 <description> 4100 Details about the reference. 4101 Set when the <datalink id="jvmtiHeapReferenceCallback.reference_kind">reference_kind</datalink> is 4102 <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>, 4103 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>, 4104 <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/>, 4105 <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/>, 4106 <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/>, 4107 or <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/>. 4108 Otherwise <code>NULL</code>. 4109 </description> 4110 </param> 4111 <param id="class_tag"> 4112 <jlong/> 4113 <description> 4114 The tag of the class of referree object (zero if the class is not tagged). 4115 If the referree object represents a runtime class, 4116 the <code>class_tag</code> is the tag 4117 associated with <code>java.lang.Class</code> 4118 (zero if <code>java.lang.Class</code> is not tagged). 4119 </description> 4120 </param> 4121 <param id="referrer_class_tag"> 4122 <jlong/> 4123 <description> 4124 The tag of the class of the referrer object (zero if the class is not tagged 4125 or the referree is a heap root). If the referrer object represents a runtime 4126 class, the <code>referrer_class_tag</code> is the tag associated with 4127 the <code>java.lang.Class</code> 4128 (zero if <code>java.lang.Class</code> is not tagged). 4129 </description> 4130 </param> 4131 <param id="size"> 4132 <jlong/> 4133 <description> 4134 Size of the referree object (in bytes). 4135 See <functionlink id="GetObjectSize"/>. 4136 </description> 4137 </param> 4138 <param id="tag_ptr"> 4139 <outptr><jlong/></outptr> 4140 <description> 4141 Points to the referree object tag value, or zero if the object is not 4142 tagged. 4143 To set the tag value to be associated with the object 4144 the agent sets the <code>jlong</code> pointed to by the parameter. 4145 </description> 4146 </param> 4147 <param id="referrer_tag_ptr"> 4148 <outptr><jlong/></outptr> 4149 <description> 4150 Points to the tag of the referrer object, or 4151 points to the zero if the referrer 4152 object is not tagged. 4153 <code>NULL</code> if the referrer in not an object (that is, 4154 this callback is reporting a heap root). 4155 To set the tag value to be associated with the referrer object 4156 the agent sets the <code>jlong</code> pointed to by the parameter. 4157 If this callback is reporting a reference from an object to itself, 4158 <code>referrer_tag_ptr == tag_ptr</code>. 4159 </description> 4160 </param> 4161 <param id="length"> 4162 <jint/> 4163 <description> 4164 If this object is an array, the length of the array. Otherwise negative one (-1). 4165 </description> 4166 </param> 4167 <param id="user_data"> 4168 <outptr><void/></outptr> 4169 <description> 4170 The user supplied data that was passed into the iteration function. 4171 </description> 4172 </param> 4173 </parameters> 4174 </callback> 4175 4176 <callback id="jvmtiPrimitiveFieldCallback" since="1.1"> 4177 <jint/> 4178 <synopsis>Primitive Field Callback</synopsis> 4179 <description> 4180 Agent supplied callback function which 4181 describes a primitive field of an object (<i>the object</i>). 4182 A primitive field is a field whose type is a primitive type. 4183 This callback will describe a static field if the object is a class, 4184 and otherwise will describe an instance field. 4185 <p/> 4186 This function should return a bit vector of the desired 4187 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>. 4188 This will determine if the entire iteration should be aborted 4189 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored). 4190 <p/> 4191 See the <internallink id="heapCallbacks">heap callback 4192 function restrictions</internallink>. 4193 </description> 4194 <parameters> 4195 <param id="kind"> 4196 <enum>jvmtiHeapReferenceKind</enum> 4197 <description> 4198 The kind of field -- instance or static (<datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> or 4199 <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>). 4200 </description> 4201 </param> 4202 <param id="info"> 4203 <inptr> 4204 <struct>jvmtiHeapReferenceInfo</struct> 4205 </inptr> 4206 <description> 4207 Which field (the field index). 4208 </description> 4209 </param> 4210 <param id="object_class_tag"> 4211 <jlong/> 4212 <description> 4213 The tag of the class of the object (zero if the class is not tagged). 4214 If the object represents a runtime class, the 4215 <code>object_class_tag</code> is the tag 4216 associated with <code>java.lang.Class</code> 4217 (zero if <code>java.lang.Class</code> is not tagged). 4218 </description> 4219 </param> 4220 <param id="object_tag_ptr"> 4221 <outptr><jlong/></outptr> 4222 <description> 4223 Points to the tag of the object, or zero if the object is not 4224 tagged. 4225 To set the tag value to be associated with the object 4226 the agent sets the <code>jlong</code> pointed to by the parameter. 4227 </description> 4228 </param> 4229 <param id="value"> 4230 <jvalue/> 4231 <description> 4232 The value of the field. 4233 </description> 4234 </param> 4235 <param id="value_type"> 4236 <enum>jvmtiPrimitiveType</enum> 4237 <description> 4238 The type of the field. 4239 </description> 4240 </param> 4241 <param id="user_data"> 4242 <outptr><void/></outptr> 4243 <description> 4244 The user supplied data that was passed into the iteration function. 4245 </description> 4246 </param> 4247 </parameters> 4248 </callback> 4249 4250 <callback id="jvmtiArrayPrimitiveValueCallback" since="1.1"> 4251 <jint/> 4252 <synopsis>Array Primitive Value Callback</synopsis> 4253 <description> 4254 Agent supplied callback function. 4255 Describes the values in an array of a primitive type. 4256 <p/> 4257 This function should return a bit vector of the desired 4258 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>. 4259 This will determine if the entire iteration should be aborted 4260 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored). 4261 <p/> 4262 See the <internallink id="heapCallbacks">heap callback 4263 function restrictions</internallink>. 4264 </description> 4265 <parameters> 4266 <param id="class_tag"> 4267 <jlong/> 4268 <description> 4269 The tag of the class of the array object (zero if the class is not tagged). 4270 </description> 4271 </param> 4272 <param id="size"> 4273 <jlong/> 4274 <description> 4275 Size of the array (in bytes). 4276 See <functionlink id="GetObjectSize"/>. 4277 </description> 4278 </param> 4279 <param id="tag_ptr"> 4280 <outptr><jlong/></outptr> 4281 <description> 4282 Points to the tag of the array object, or zero if the object is not 4283 tagged. 4284 To set the tag value to be associated with the object 4285 the agent sets the <code>jlong</code> pointed to by the parameter. 4286 </description> 4287 </param> 4288 <param id="element_count"> 4289 <jint/> 4290 <description> 4291 The length of the primitive array. 4292 </description> 4293 </param> 4294 <param id="element_type"> 4295 <enum>jvmtiPrimitiveType</enum> 4296 <description> 4297 The type of the elements of the array. 4298 </description> 4299 </param> 4300 <param id="elements"> 4301 <vmbuf><void/></vmbuf> 4302 <description> 4303 The elements of the array in a packed array of <code>element_count</code> 4304 items of <code>element_type</code> size each. 4305 </description> 4306 </param> 4307 <param id="user_data"> 4308 <outptr><void/></outptr> 4309 <description> 4310 The user supplied data that was passed into the iteration function. 4311 </description> 4312 </param> 4313 </parameters> 4314 </callback> 4315 4316 <callback id="jvmtiStringPrimitiveValueCallback" since="1.1"> 4317 <jint/> 4318 <synopsis>String Primitive Value Callback</synopsis> 4319 <description> 4320 Agent supplied callback function. 4321 Describes the value of a java.lang.String. 4322 <p/> 4323 This function should return a bit vector of the desired 4324 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink>. 4325 This will determine if the entire iteration should be aborted 4326 (the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored). 4327 <p/> 4328 See the <internallink id="heapCallbacks">heap callback 4329 function restrictions</internallink>. 4330 </description> 4331 <parameters> 4332 <param id="class_tag"> 4333 <jlong/> 4334 <description> 4335 The tag of the class of the String class (zero if the class is not tagged). 4336 <issue>Is this needed?</issue> 4337 </description> 4338 </param> 4339 <param id="size"> 4340 <jlong/> 4341 <description> 4342 Size of the string (in bytes). 4343 See <functionlink id="GetObjectSize"/>. 4344 </description> 4345 </param> 4346 <param id="tag_ptr"> 4347 <outptr><jlong/></outptr> 4348 <description> 4349 Points to the tag of the String object, or zero if the object is not 4350 tagged. 4351 To set the tag value to be associated with the object 4352 the agent sets the <code>jlong</code> pointed to by the parameter. 4353 </description> 4354 </param> 4355 <param id="value"> 4356 <vmbuf><jchar/></vmbuf> 4357 <description> 4358 The value of the String, encoded as a Unicode string. 4359 </description> 4360 </param> 4361 <param id="value_length"> 4362 <jint/> 4363 <description> 4364 The length of the string. 4365 The length is equal to the number of 16-bit Unicode 4366 characters in the string. 4367 </description> 4368 </param> 4369 <param id="user_data"> 4370 <outptr><void/></outptr> 4371 <description> 4372 The user supplied data that was passed into the iteration function. 4373 </description> 4374 </param> 4375 </parameters> 4376 </callback> 4377 4378 4379 <callback id="jvmtiReservedCallback" since="1.1"> 4380 <jint/> 4381 <synopsis>reserved for future use Callback</synopsis> 4382 <description> 4383 Placeholder -- reserved for future use. 4384 </description> 4385 <parameters> 4386 </parameters> 4387 </callback> 4388 4389 <function id="FollowReferences" num="115" since="1.1"> 4390 <synopsis>Follow References</synopsis> 4391 <description> 4392 This function initiates a traversal over the objects that are 4393 directly and indirectly reachable from the specified object or, 4394 if <code>initial_object</code> is not specified, all objects 4395 reachable from the heap roots. 4396 The heap root are the set of system classes, 4397 JNI globals, references from thread stacks, and other objects used as roots 4398 for the purposes of garbage collection. 4399 <p/> 4400 This function operates by traversing the reference graph. 4401 Let <i>A</i>, <i>B</i>, ... represent objects. 4402 When a reference from <i>A</i> to <i>B</i> is traversed, 4403 when a reference from a heap root to <i>B</i> is traversed, 4404 or when <i>B</i> is specified as the <paramlink id="initial_object"/>, 4405 then <i>B</i> is said to be <i>visited</i>. 4406 A reference from <i>A</i> to <i>B</i> is not traversed until <i>A</i> 4407 is visited. 4408 References are reported in the same order that the references are traversed. 4409 Object references are reported by invoking the agent supplied 4410 callback function <functionlink id="jvmtiHeapReferenceCallback"/>. 4411 In a reference from <i>A</i> to <i>B</i>, <i>A</i> is known 4412 as the <i>referrer</i> and <i>B</i> as the <i>referree</i>. 4413 The callback is invoked exactly once for each reference from a referrer; 4414 this is true even if there are reference cycles or multiple paths to 4415 the referrer. 4416 There may be more than one reference between a referrer and a referree, 4417 each reference is reported. 4418 These references may be distinguished by examining the 4419 <datalink 4420 id="jvmtiHeapReferenceCallback.reference_kind"><code>reference_kind</code></datalink> 4421 and 4422 <datalink 4423 id="jvmtiHeapReferenceCallback.reference_info"><code>reference_info</code></datalink> 4424 parameters of the <functionlink id="jvmtiHeapReferenceCallback"/> callback. 4425 <p/> 4426 This function reports a Java programming language view of object references, 4427 not a virtual machine implementation view. The following object references 4428 are reported when they are non-null: 4429 <ul> 4430 <li>Instance objects report references to each non-primitive instance fields 4431 (including inherited fields).</li> 4432 <li>Instance objects report a reference to the object type (class).</li> 4433 <li>Classes report a reference to the superclass and directly 4434 implemented/extended interfaces.</li> 4435 <li>Classes report a reference to the class loader, protection domain, 4436 signers, and resolved entries in the constant pool.</li> 4437 <li>Classes report a reference to each directly declared non-primitive 4438 static field.</li> 4439 <li>Arrays report a reference to the array type (class) and each 4440 array element.</li> 4441 <li>Primitive arrays report a reference to the array type.</li> 4442 </ul> 4443 <p/> 4444 This function can also be used to examine primitive (non-object) values. 4445 The primitive value of an array or String 4446 is reported after the object has been visited; 4447 it is reported by invoking the agent supplied callback function 4448 <functionlink id="jvmtiArrayPrimitiveValueCallback"/> or 4449 <functionlink id="jvmtiStringPrimitiveValueCallback"/>. 4450 A primitive field 4451 is reported after the object with that field is visited; 4452 it is reported by invoking the agent supplied callback function 4453 <functionlink id="jvmtiPrimitiveFieldCallback"/>. 4454 <p/> 4455 Whether a callback is provided or is <code>NULL</code> only determines 4456 whether the callback will be invoked, it does not influence 4457 which objects are visited nor does it influence whether other callbacks 4458 will be invoked. 4459 However, the 4460 <datalink id="jvmtiHeapVisitControl">visit control flags</datalink> 4461 returned by <functionlink id="jvmtiHeapReferenceCallback"/> 4462 do determine if the objects referenced by the 4463 current object as visited. 4464 The <datalink id="jvmtiHeapFilter">heap filter flags</datalink> 4465 and <paramlink id="klass"/> provided as parameters to this function 4466 do not control which objects are visited but they do control which 4467 objects and primitive values are reported by the callbacks. 4468 For example, if the only callback that was set is 4469 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> and <code>klass</code> 4470 is set to the array of bytes class, then only arrays of byte will be 4471 reported. 4472 The table below summarizes this: 4473 <p/> 4474 <table> 4475 <tr> 4476 <th/> 4477 <th> 4478 Controls objects visited 4479 </th> 4480 <th> 4481 Controls objects reported 4482 </th> 4483 <th> 4484 Controls primitives reported 4485 </th> 4486 </tr> 4487 <tr> 4488 <th align="left"> 4489 the 4490 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink> 4491 returned by <functionlink id="jvmtiHeapReferenceCallback"/> 4492 </th> 4493 <td> 4494 <b>Yes</b> 4495 </td> 4496 <td> 4497 <b>Yes</b>, since visits are controlled 4498 </td> 4499 <td> 4500 <b>Yes</b>, since visits are controlled 4501 </td> 4502 </tr> 4503 <tr> 4504 <th align="left"> 4505 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> 4506 in <paramlink id="callbacks"/> set 4507 </th> 4508 <td> 4509 No 4510 </td> 4511 <td> 4512 <b>Yes</b> 4513 </td> 4514 <td> 4515 No 4516 </td> 4517 </tr> 4518 <tr> 4519 <th align="left"> 4520 <paramlink id="heap_filter"/> 4521 </th> 4522 <td> 4523 No 4524 </td> 4525 <td> 4526 <b>Yes</b> 4527 </td> 4528 <td> 4529 <b>Yes</b> 4530 </td> 4531 </tr> 4532 <tr> 4533 <th align="left"> 4534 <paramlink id="klass"/> 4535 </th> 4536 <td> 4537 No 4538 </td> 4539 <td> 4540 <b>Yes</b> 4541 </td> 4542 <td> 4543 <b>Yes</b> 4544 </td> 4545 </tr> 4546 </table> 4547 <p/> 4548 During the execution of this function the state of the heap 4549 does not change: no objects are allocated, no objects are 4550 garbage collected, and the state of objects (including 4551 held values) does not change. 4552 As a result, threads executing Java 4553 programming language code, threads attempting to resume the 4554 execution of Java programming language code, and threads 4555 attempting to execute JNI functions are typically stalled. 4556 </description> 4557 <origin>new</origin> 4558 <capabilities> 4559 <required id="can_tag_objects"></required> 4560 </capabilities> 4561 <parameters> 4562 <param id="heap_filter"> 4563 <jint/> 4564 <description> 4565 This bit vector of 4566 <datalink id="jvmtiHeapFilter">heap filter flags</datalink>. 4567 restricts the objects for which the callback function is called. 4568 This applies to both the object and primitive callbacks. 4569 </description> 4570 </param> 4571 <param id="klass"> 4572 <ptrtype> 4573 <jclass/> 4574 <nullok>callbacks are not limited to instances of a particular 4575 class</nullok> 4576 </ptrtype> 4577 <description> 4578 Callbacks are only reported when the object is an instance of 4579 this class. 4580 Objects which are instances of a subclass of <code>klass</code> 4581 are not reported. 4582 If <code>klass</code> is an interface, no objects are reported. 4583 This applies to both the object and primitive callbacks. 4584 </description> 4585 </param> 4586 <param id="initial_object"> 4587 <ptrtype> 4588 <jobject/> 4589 <nullok>references are followed from the heap roots</nullok> 4590 </ptrtype> 4591 <description> 4592 The object to follow 4593 </description> 4594 </param> 4595 <param id="callbacks"> 4596 <inptr> 4597 <struct>jvmtiHeapCallbacks</struct> 4598 </inptr> 4599 <description> 4600 Structure defining the set of callback functions. 4601 </description> 4602 </param> 4603 <param id="user_data"> 4604 <inbuf> 4605 <void/> 4606 <nullok><code>NULL</code> is passed as the user supplied data</nullok> 4607 </inbuf> 4608 <description> 4609 User supplied data to be passed to the callback. 4610 </description> 4611 </param> 4612 </parameters> 4613 <errors> 4614 <error id="JVMTI_ERROR_INVALID_CLASS"> 4615 <paramlink id="klass"/> is not a valid class. 4616 </error> 4617 <error id="JVMTI_ERROR_INVALID_OBJECT"> 4618 <paramlink id="initial_object"/> is not a valid object. 4619 </error> 4620 </errors> 4621 </function> 4622 4623 4624 <function id="IterateThroughHeap" num="116" since="1.1"> 4625 <synopsis>Iterate Through Heap</synopsis> 4626 <description> 4627 Initiate an iteration over all objects in the heap. 4628 This includes both reachable and 4629 unreachable objects. Objects are visited in no particular order. 4630 <p/> 4631 Heap objects are reported by invoking the agent supplied 4632 callback function <functionlink id="jvmtiHeapIterationCallback"/>. 4633 References between objects are not reported. 4634 If only reachable objects are desired, or if object reference information 4635 is needed, use <functionlink id="FollowReferences"/>. 4636 <p/> 4637 This function can also be used to examine primitive (non-object) values. 4638 The primitive value of an array or String 4639 is reported after the object has been visited; 4640 it is reported by invoking the agent supplied callback function 4641 <functionlink id="jvmtiArrayPrimitiveValueCallback"/> or 4642 <functionlink id="jvmtiStringPrimitiveValueCallback"/>. 4643 A primitive field 4644 is reported after the object with that field is visited; 4645 it is reported by invoking the agent supplied 4646 callback function 4647 <functionlink id="jvmtiPrimitiveFieldCallback"/>. 4648 <p/> 4649 Unless the iteration is aborted by the 4650 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink> 4651 returned by a callback, all objects in the heap are visited. 4652 Whether a callback is provided or is <code>NULL</code> only determines 4653 whether the callback will be invoked, it does not influence 4654 which objects are visited nor does it influence whether other callbacks 4655 will be invoked. 4656 The <datalink id="jvmtiHeapFilter">heap filter flags</datalink> 4657 and <paramlink id="klass"/> provided as parameters to this function 4658 do not control which objects are visited but they do control which 4659 objects and primitive values are reported by the callbacks. 4660 For example, if the only callback that was set is 4661 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> and <code>klass</code> 4662 is set to the array of bytes class, then only arrays of byte will be 4663 reported. The table below summarizes this (contrast this with 4664 <functionlink id="FollowReferences"/>): 4665 <p/> 4666 <table> 4667 <tr> 4668 <th/> 4669 <th> 4670 Controls objects visited 4671 </th> 4672 <th> 4673 Controls objects reported 4674 </th> 4675 <th> 4676 Controls primitives reported 4677 </th> 4678 </tr> 4679 <tr> 4680 <th align="left"> 4681 the 4682 <datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink> 4683 returned by <functionlink id="jvmtiHeapIterationCallback"/> 4684 </th> 4685 <td> 4686 No<br/>(unless they abort the iteration) 4687 </td> 4688 <td> 4689 No<br/>(unless they abort the iteration) 4690 </td> 4691 <td> 4692 No<br/>(unless they abort the iteration) 4693 </td> 4694 </tr> 4695 <tr> 4696 <th align="left"> 4697 <fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> 4698 in <paramlink id="callbacks"/> set 4699 </th> 4700 <td> 4701 No 4702 </td> 4703 <td> 4704 <b>Yes</b> 4705 </td> 4706 <td> 4707 No 4708 </td> 4709 </tr> 4710 <tr> 4711 <th align="left"> 4712 <paramlink id="heap_filter"/> 4713 </th> 4714 <td> 4715 No 4716 </td> 4717 <td> 4718 <b>Yes</b> 4719 </td> 4720 <td> 4721 <b>Yes</b> 4722 </td> 4723 </tr> 4724 <tr> 4725 <th align="left"> 4726 <paramlink id="klass"/> 4727 </th> 4728 <td> 4729 No 4730 </td> 4731 <td> 4732 <b>Yes</b> 4733 </td> 4734 <td> 4735 <b>Yes</b> 4736 </td> 4737 </tr> 4738 </table> 4739 <p/> 4740 During the execution of this function the state of the heap 4741 does not change: no objects are allocated, no objects are 4742 garbage collected, and the state of objects (including 4743 held values) does not change. 4744 As a result, threads executing Java 4745 programming language code, threads attempting to resume the 4746 execution of Java programming language code, and threads 4747 attempting to execute JNI functions are typically stalled. 4748 </description> 4749 <origin>new</origin> 4750 <capabilities> 4751 <required id="can_tag_objects"></required> 4752 </capabilities> 4753 <parameters> 4754 <param id="heap_filter"> 4755 <jint/> 4756 <description> 4757 This bit vector of 4758 <datalink id="jvmtiHeapFilter">heap filter flags</datalink>. 4759 restricts the objects for which the callback function is called. 4760 This applies to both the object and primitive callbacks. 4761 </description> 4762 </param> 4763 <param id="klass"> 4764 <ptrtype> 4765 <jclass/> 4766 <nullok>callbacks are not limited to instances of a particular class</nullok> 4767 </ptrtype> 4768 <description> 4769 Callbacks are only reported when the object is an instance of 4770 this class. 4771 Objects which are instances of a subclass of <code>klass</code> 4772 are not reported. 4773 If <code>klass</code> is an interface, no objects are reported. 4774 This applies to both the object and primitive callbacks. 4775 </description> 4776 </param> 4777 <param id="callbacks"> 4778 <inptr> 4779 <struct>jvmtiHeapCallbacks</struct> 4780 </inptr> 4781 <description> 4782 Structure defining the set callback functions. 4783 </description> 4784 </param> 4785 <param id="user_data"> 4786 <inbuf> 4787 <void/> 4788 <nullok><code>NULL</code> is passed as the user supplied data</nullok> 4789 </inbuf> 4790 <description> 4791 User supplied data to be passed to the callback. 4792 </description> 4793 </param> 4794 </parameters> 4795 <errors> 4796 <error id="JVMTI_ERROR_INVALID_CLASS"> 4797 <paramlink id="klass"/> is not a valid class. 4798 </error> 4799 </errors> 4800 </function> 4801 4802 <function id="GetTag" phase="start" num="106"> 4803 <synopsis>Get Tag</synopsis> 4804 <description> 4805 Retrieve the tag associated with an object. 4806 The tag is a long value typically used to store a 4807 unique identifier or pointer to object information. 4808 The tag is set with 4809 <functionlink id="SetTag"></functionlink>. 4810 Objects for which no tags have been set return a 4811 tag value of zero. 4812 </description> 4813 <origin>new</origin> 4814 <capabilities> 4815 <required id="can_tag_objects"></required> 4816 </capabilities> 4817 <parameters> 4818 <param id="object"> 4819 <jobject/> 4820 <description> 4821 The object whose tag is to be retrieved. 4822 </description> 4823 </param> 4824 <param id="tag_ptr"> 4825 <outptr><jlong/></outptr> 4826 <description> 4827 On return, the referenced long is set to the value 4828 of the tag. 4829 </description> 4830 </param> 4831 </parameters> 4832 <errors> 4833 </errors> 4834 </function> 4835 4836 <function id="SetTag" phase="start" num="107"> 4837 <synopsis>Set Tag</synopsis> 4838 <description> 4839 Set the tag associated with an object. 4840 The tag is a long value typically used to store a 4841 unique identifier or pointer to object information. 4842 The tag is visible with 4843 <functionlink id="GetTag"></functionlink>. 4844 </description> 4845 <origin>new</origin> 4846 <capabilities> 4847 <required id="can_tag_objects"></required> 4848 </capabilities> 4849 <parameters> 4850 <param id="object"> 4851 <jobject/> 4852 <description> 4853 The object whose tag is to be set. 4854 </description> 4855 </param> 4856 <param id="tag"> 4857 <jlong/> 4858 <description> 4859 The new value of the tag. 4860 </description> 4861 </param> 4862 </parameters> 4863 <errors> 4864 </errors> 4865 </function> 4866 4867 <function id="GetObjectsWithTags" num="114"> 4868 <synopsis>Get Objects With Tags</synopsis> 4869 <description> 4870 Return objects in the heap with the specified tags. 4871 The format is parallel arrays of objects and tags. 4872 </description> 4873 <origin>new</origin> 4874 <capabilities> 4875 <required id="can_tag_objects"></required> 4876 </capabilities> 4877 <parameters> 4878 <param id="tag_count"> 4879 <jint min="0"/> 4880 <description> 4881 Number of tags to scan for. 4882 </description> 4883 </param> 4884 <param id="tags"> 4885 <inbuf incount="tag_count"> 4886 <jlong/> 4887 </inbuf> 4888 <description> 4889 Scan for objects with these tags. 4890 Zero is not permitted in this array. 4891 </description> 4892 </param> 4893 <param id="count_ptr"> 4894 <outptr> 4895 <jint/> 4896 </outptr> 4897 <description> 4898 Return the number of objects with any of the tags 4899 in <paramlink id="tags"/>. 4900 </description> 4901 </param> 4902 <param id="object_result_ptr"> 4903 <allocbuf outcount="count_ptr"> 4904 <jobject/> 4905 <nullok>this information is not returned</nullok> 4906 </allocbuf> 4907 <description> 4908 Returns the array of objects with any of the tags 4909 in <paramlink id="tags"/>. 4910 </description> 4911 </param> 4912 <param id="tag_result_ptr"> 4913 <allocbuf outcount="count_ptr"> 4914 <jlong/> 4915 <nullok>this information is not returned</nullok> 4916 </allocbuf> 4917 <description> 4918 For each object in <paramlink id="object_result_ptr"/>, 4919 return the tag at the corresponding index. 4920 </description> 4921 </param> 4922 </parameters> 4923 <errors> 4924 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 4925 Zero is present in <paramlink id="tags"></paramlink>. 4926 </error> 4927 </errors> 4928 </function> 4929 4930 <function id="ForceGarbageCollection" num="108"> 4931 <synopsis>Force Garbage Collection</synopsis> 4932 <description> 4933 Force the VM to perform a garbage collection. 4934 The garbage collection is as complete as possible. 4935 This function does not cause finalizers to be run. 4936 This function does not return until the garbage collection 4937 is finished. 4938 <p/> 4939 Although garbage collection is as complete 4940 as possible there is no guarantee that all 4941 <eventlink id="ObjectFree"/> 4942 events will have been 4943 sent by the time that this function 4944 returns. In particular, an object may be 4945 prevented from being freed because it 4946 is awaiting finalization. 4947 </description> 4948 <origin>new</origin> 4949 <capabilities> 4950 </capabilities> 4951 <parameters> 4952 </parameters> 4953 <errors> 4954 </errors> 4955 </function> 4956 4957 4958 </category> 4959 4960 <category id="Heap_1_0" label="Heap (1.0)"> 4961 <intro> 4962 <b> 4963 These functions and data types were introduced in the original 4964 <jvmti/> version 1.0 and have been superseded by more 4965 </b> 4966 <internallink id="Heap"><b>powerful and flexible versions</b></internallink> 4967 <b> 4968 which: 4969 </b> 4970 <ul> 4971 <li> 4972 <b> 4973 Allow access to primitive values (the value of Strings, arrays, 4974 and primitive fields) 4975 </b> 4976 </li> 4977 <li> 4978 <b> 4979 Allow the tag of the referrer to be set, thus enabling more 4980 efficient localized reference graph building 4981 </b> 4982 </li> 4983 <li> 4984 <b> 4985 Provide more extensive filtering abilities 4986 </b> 4987 </li> 4988 <li> 4989 <b> 4990 Are extensible, allowing their abilities to grow in future versions of <jvmti/> 4991 </b> 4992 </li> 4993 </ul> 4994 <p/> 4995 <b>Please use the </b> 4996 <internallink id="Heap"><b>current Heap functions</b></internallink>. 4997 <p/> 4998 <constants id="jvmtiHeapObjectFilter" label="Heap Object Filter Enumeration" kind="enum"> 4999 <constant id="JVMTI_HEAP_OBJECT_TAGGED" num="1"> 5000 Tagged objects only. 5001 </constant> 5002 <constant id="JVMTI_HEAP_OBJECT_UNTAGGED" num="2"> 5003 Untagged objects only. 5004 </constant> 5005 <constant id="JVMTI_HEAP_OBJECT_EITHER" num="3"> 5006 Either tagged or untagged objects. 5007 </constant> 5008 </constants> 5009 5010 <constants id="jvmtiHeapRootKind" label="Heap Root Kind Enumeration" kind="enum"> 5011 <constant id="JVMTI_HEAP_ROOT_JNI_GLOBAL" num="1"> 5012 JNI global reference. 5013 </constant> 5014 <constant id="JVMTI_HEAP_ROOT_SYSTEM_CLASS" num="2"> 5015 System class. 5016 </constant> 5017 <constant id="JVMTI_HEAP_ROOT_MONITOR" num="3"> 5018 Monitor. 5019 </constant> 5020 <constant id="JVMTI_HEAP_ROOT_STACK_LOCAL" num="4"> 5021 Stack local. 5022 </constant> 5023 <constant id="JVMTI_HEAP_ROOT_JNI_LOCAL" num="5"> 5024 JNI local reference. 5025 </constant> 5026 <constant id="JVMTI_HEAP_ROOT_THREAD" num="6"> 5027 Thread. 5028 </constant> 5029 <constant id="JVMTI_HEAP_ROOT_OTHER" num="7"> 5030 Other. 5031 </constant> 5032 </constants> 5033 5034 <constants id="jvmtiObjectReferenceKind" label="Object Reference Enumeration" kind="enum"> 5035 <constant id="JVMTI_REFERENCE_CLASS" num="1"> 5036 Reference from an object to its class. 5037 </constant> 5038 <constant id="JVMTI_REFERENCE_FIELD" num="2"> 5039 Reference from an object to the value of one of its instance fields. 5040 For references of this kind the <code>referrer_index</code> 5041 parameter to the <internallink id="jvmtiObjectReferenceCallback"> 5042 jvmtiObjectReferenceCallback</internallink> is the index of the 5043 the instance field. The index is based on the order of all the 5044 object's fields. This includes all fields of the directly declared 5045 static and instance fields in the class, and includes all fields (both 5046 public and private) fields declared in superclasses and superinterfaces. 5047 The index is thus calculated by summing the index of the field in the directly 5048 declared class (see <functionlink id="GetClassFields"/>), with the total 5049 number of fields (both public and private) declared in all superclasses 5050 and superinterfaces. The index starts at zero. 5051 </constant> 5052 <constant id="JVMTI_REFERENCE_ARRAY_ELEMENT" num="3"> 5053 Reference from an array to one of its elements. 5054 For references of this kind the <code>referrer_index</code> 5055 parameter to the <internallink id="jvmtiObjectReferenceCallback"> 5056 jvmtiObjectReferenceCallback</internallink> is the array index. 5057 </constant> 5058 <constant id="JVMTI_REFERENCE_CLASS_LOADER" num="4"> 5059 Reference from a class to its class loader. 5060 </constant> 5061 <constant id="JVMTI_REFERENCE_SIGNERS" num="5"> 5062 Reference from a class to its signers array. 5063 </constant> 5064 <constant id="JVMTI_REFERENCE_PROTECTION_DOMAIN" num="6"> 5065 Reference from a class to its protection domain. 5066 </constant> 5067 <constant id="JVMTI_REFERENCE_INTERFACE" num="7"> 5068 Reference from a class to one of its interfaces. 5069 </constant> 5070 <constant id="JVMTI_REFERENCE_STATIC_FIELD" num="8"> 5071 Reference from a class to the value of one of its static fields. 5072 For references of this kind the <code>referrer_index</code> 5073 parameter to the <internallink id="jvmtiObjectReferenceCallback"> 5074 jvmtiObjectReferenceCallback</internallink> is the index of the 5075 the static field. The index is based on the order of all the 5076 object's fields. This includes all fields of the directly declared 5077 static and instance fields in the class, and includes all fields (both 5078 public and private) fields declared in superclasses and superinterfaces. 5079 The index is thus calculated by summing the index of the field in the directly 5080 declared class (see <functionlink id="GetClassFields"/>), with the total 5081 number of fields (both public and private) declared in all superclasses 5082 and superinterfaces. The index starts at zero. 5083 Note: this definition differs from that in the <jvmti/> 1.0 Specification. 5084 <rationale>No known implementations used the 1.0 definition.</rationale> 5085 </constant> 5086 <constant id="JVMTI_REFERENCE_CONSTANT_POOL" num="9"> 5087 Reference from a class to a resolved entry in the constant pool. 5088 For references of this kind the <code>referrer_index</code> 5089 parameter to the <internallink id="jvmtiObjectReferenceCallback"> 5090 jvmtiObjectReferenceCallback</internallink> is the index into 5091 constant pool table of the class, starting at 1. See 5092 <vmspec chapter="4.4"/>. 5093 </constant> 5094 </constants> 5095 5096 <constants id="jvmtiIterationControl" label="Iteration Control Enumeration" kind="enum"> 5097 <constant id="JVMTI_ITERATION_CONTINUE" num="1"> 5098 Continue the iteration. 5099 If this is a reference iteration, follow the references of this object. 5100 </constant> 5101 <constant id="JVMTI_ITERATION_IGNORE" num="2"> 5102 Continue the iteration. 5103 If this is a reference iteration, ignore the references of this object. 5104 </constant> 5105 <constant id="JVMTI_ITERATION_ABORT" num="0"> 5106 Abort the iteration. 5107 </constant> 5108 </constants> 5109 </intro> 5110 5111 <callback id="jvmtiHeapObjectCallback"> 5112 <enum>jvmtiIterationControl</enum> 5113 <synopsis>Heap Object Callback</synopsis> 5114 <description> 5115 Agent supplied callback function. 5116 Describes (but does not pass in) an object in the heap. 5117 <p/> 5118 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration, 5119 or <code>JVMTI_ITERATION_ABORT</code> to stop iteration. 5120 <p/> 5121 See the <internallink id="heapCallbacks">heap callback 5122 function restrictions</internallink>. 5123 </description> 5124 <parameters> 5125 <param id="class_tag"> 5126 <jlong/> 5127 <description> 5128 The tag of the class of object (zero if the class is not tagged). 5129 If the object represents a runtime class, 5130 the <code>class_tag</code> is the tag 5131 associated with <code>java.lang.Class</code> 5132 (zero if <code>java.lang.Class</code> is not tagged). 5133 </description> 5134 </param> 5135 <param id="size"> 5136 <jlong/> 5137 <description> 5138 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>. 5139 </description> 5140 </param> 5141 <param id="tag_ptr"> 5142 <outptr><jlong/></outptr> 5143 <description> 5144 The object tag value, or zero if the object is not tagged. 5145 To set the tag value to be associated with the object 5146 the agent sets the <code>jlong</code> pointed to by the parameter. 5147 </description> 5148 </param> 5149 <param id="user_data"> 5150 <outptr><void/></outptr> 5151 <description> 5152 The user supplied data that was passed into the iteration function. 5153 </description> 5154 </param> 5155 </parameters> 5156 </callback> 5157 5158 <callback id="jvmtiHeapRootCallback"> 5159 <enum>jvmtiIterationControl</enum> 5160 <synopsis>Heap Root Object Callback</synopsis> 5161 <description> 5162 Agent supplied callback function. 5163 Describes (but does not pass in) an object that is a root for the purposes 5164 of garbage collection. 5165 <p/> 5166 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration, 5167 <code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing 5168 references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration. 5169 <p/> 5170 See the <internallink id="heapCallbacks">heap callback 5171 function restrictions</internallink>. 5172 </description> 5173 <parameters> 5174 <param id="root_kind"> 5175 <enum>jvmtiHeapRootKind</enum> 5176 <description> 5177 The kind of heap root. 5178 </description> 5179 </param> 5180 <param id="class_tag"> 5181 <jlong/> 5182 <description> 5183 The tag of the class of object (zero if the class is not tagged). 5184 If the object represents a runtime class, the <code>class_tag</code> is the tag 5185 associated with <code>java.lang.Class</code> 5186 (zero if <code>java.lang.Class</code> is not tagged). 5187 </description> 5188 </param> 5189 <param id="size"> 5190 <jlong/> 5191 <description> 5192 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>. 5193 </description> 5194 </param> 5195 <param id="tag_ptr"> 5196 <outptr><jlong/></outptr> 5197 <description> 5198 The object tag value, or zero if the object is not tagged. 5199 To set the tag value to be associated with the object 5200 the agent sets the <code>jlong</code> pointed to by the parameter. 5201 </description> 5202 </param> 5203 <param id="user_data"> 5204 <outptr><void/></outptr> 5205 <description> 5206 The user supplied data that was passed into the iteration function. 5207 </description> 5208 </param> 5209 </parameters> 5210 </callback> 5211 5212 <callback id="jvmtiStackReferenceCallback"> 5213 <enum>jvmtiIterationControl</enum> 5214 <synopsis>Stack Reference Object Callback</synopsis> 5215 <description> 5216 Agent supplied callback function. 5217 Describes (but does not pass in) an object on the stack that is a root for 5218 the purposes of garbage collection. 5219 <p/> 5220 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration, 5221 <code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing 5222 references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration. 5223 <p/> 5224 See the <internallink id="heapCallbacks">heap callback 5225 function restrictions</internallink>. 5226 </description> 5227 <parameters> 5228 <param id="root_kind"> 5229 <enum>jvmtiHeapRootKind</enum> 5230 <description> 5231 The kind of root (either <code>JVMTI_HEAP_ROOT_STACK_LOCAL</code> or 5232 <code>JVMTI_HEAP_ROOT_JNI_LOCAL</code>). 5233 </description> 5234 </param> 5235 <param id="class_tag"> 5236 <jlong/> 5237 <description> 5238 The tag of the class of object (zero if the class is not tagged). 5239 If the object represents a runtime class, the <code>class_tag</code> is the tag 5240 associated with <code>java.lang.Class</code> 5241 (zero if <code>java.lang.Class</code> is not tagged). 5242 </description> 5243 </param> 5244 <param id="size"> 5245 <jlong/> 5246 <description> 5247 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>. 5248 </description> 5249 </param> 5250 <param id="tag_ptr"> 5251 <outptr><jlong/></outptr> 5252 <description> 5253 The object tag value, or zero if the object is not tagged. 5254 To set the tag value to be associated with the object 5255 the agent sets the <code>jlong</code> pointed to by the parameter. 5256 </description> 5257 </param> 5258 <param id="thread_tag"> 5259 <jlong/> 5260 <description> 5261 The tag of the thread corresponding to this stack, zero if not tagged. 5262 </description> 5263 </param> 5264 <param id="depth"> 5265 <jint/> 5266 <description> 5267 The depth of the frame. 5268 </description> 5269 </param> 5270 <param id="method"> 5271 <jmethodID/> 5272 <description> 5273 The method executing in this frame. 5274 </description> 5275 </param> 5276 <param id="slot"> 5277 <jint/> 5278 <description> 5279 The slot number. 5280 </description> 5281 </param> 5282 <param id="user_data"> 5283 <outptr><void/></outptr> 5284 <description> 5285 The user supplied data that was passed into the iteration function. 5286 </description> 5287 </param> 5288 </parameters> 5289 </callback> 5290 5291 <callback id="jvmtiObjectReferenceCallback"> 5292 <enum>jvmtiIterationControl</enum> 5293 <synopsis>Object Reference Callback</synopsis> 5294 <description> 5295 Agent supplied callback function. 5296 Describes a reference from an object (the referrer) to another object 5297 (the referree). 5298 <p/> 5299 Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration, 5300 <code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing 5301 references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration. 5302 <p/> 5303 See the <internallink id="heapCallbacks">heap callback 5304 function restrictions</internallink>. 5305 </description> 5306 <parameters> 5307 <param id="reference_kind"> 5308 <enum>jvmtiObjectReferenceKind</enum> 5309 <description> 5310 The type of reference. 5311 </description> 5312 </param> 5313 <param id="class_tag"> 5314 <jlong/> 5315 <description> 5316 The tag of the class of referree object (zero if the class is not tagged). 5317 If the referree object represents a runtime class, 5318 the <code>class_tag</code> is the tag 5319 associated with <code>java.lang.Class</code> 5320 (zero if <code>java.lang.Class</code> is not tagged). 5321 </description> 5322 </param> 5323 <param id="size"> 5324 <jlong/> 5325 <description> 5326 Size of the referree object (in bytes). 5327 See <functionlink id="GetObjectSize"/>. 5328 </description> 5329 </param> 5330 <param id="tag_ptr"> 5331 <outptr><jlong/></outptr> 5332 <description> 5333 The referree object tag value, or zero if the object is not 5334 tagged. 5335 To set the tag value to be associated with the object 5336 the agent sets the <code>jlong</code> pointed to by the parameter. 5337 </description> 5338 </param> 5339 <param id="referrer_tag"> 5340 <jlong/> 5341 <description> 5342 The tag of the referrer object, or zero if the referrer 5343 object is not tagged. 5344 </description> 5345 </param> 5346 <param id="referrer_index"> 5347 <jint/> 5348 <description> 5349 For references of type <code>JVMTI_REFERENCE_FIELD</code> or 5350 <code>JVMTI_REFERENCE_STATIC_FIELD</code> the index 5351 of the field in the referrer object. The index is based on the 5352 order of all the object's fields - see <internallink 5353 id="JVMTI_REFERENCE_FIELD">JVMTI_REFERENCE_FIELD</internallink> 5354 or <internallink 5355 id="JVMTI_REFERENCE_STATIC_FIELD">JVMTI_REFERENCE_STATIC_FIELD 5356 </internallink> for further description. 5357 <p/> 5358 For references of type <code>JVMTI_REFERENCE_ARRAY_ELEMENT</code> 5359 the array index - see <internallink id="JVMTI_REFERENCE_ARRAY_ELEMENT"> 5360 JVMTI_REFERENCE_ARRAY_ELEMENT</internallink> for further description. 5361 <p/> 5362 For references of type <code>JVMTI_REFERENCE_CONSTANT_POOL</code> 5363 the index into the constant pool of the class - see 5364 <internallink id="JVMTI_REFERENCE_CONSTANT_POOL"> 5365 JVMTI_REFERENCE_CONSTANT_POOL</internallink> for further 5366 description. 5367 <p/> 5368 For references of other kinds the <code>referrer_index</code> is 5369 <code>-1</code>. 5370 </description> 5371 </param> 5372 <param id="user_data"> 5373 <outptr><void/></outptr> 5374 <description> 5375 The user supplied data that was passed into the iteration function. 5376 </description> 5377 </param> 5378 </parameters> 5379 </callback> 5380 5381 <function id="IterateOverObjectsReachableFromObject" num="109"> 5382 <synopsis>Iterate Over Objects Reachable From Object</synopsis> 5383 <description> 5384 This function iterates over all objects that are directly 5385 and indirectly reachable from the specified object. 5386 For each object <i>A</i> (known 5387 as the referrer) with a reference to object <i>B</i> the specified 5388 callback function is called to describe the object reference. 5389 The callback is called exactly once for each reference from a referrer; 5390 this is true even if there are reference cycles or multiple paths to 5391 the referrer. 5392 There may be more than one reference between a referrer and a referree, 5393 These may be distinguished by the 5394 <datalink id="jvmtiObjectReferenceCallback.reference_kind"></datalink> and 5395 <datalink id="jvmtiObjectReferenceCallback.referrer_index"></datalink>. 5396 The callback for an object will always occur after the callback for 5397 its referrer. 5398 <p/> 5399 See <functionlink id="FollowReferences"/> for the object 5400 references which are reported. 5401 <p/> 5402 During the execution of this function the state of the heap 5403 does not change: no objects are allocated, no objects are 5404 garbage collected, and the state of objects (including 5405 held values) does not change. 5406 As a result, threads executing Java 5407 programming language code, threads attempting to resume the 5408 execution of Java programming language code, and threads 5409 attempting to execute JNI functions are typically stalled. 5410 </description> 5411 <origin>new</origin> 5412 <capabilities> 5413 <required id="can_tag_objects"></required> 5414 </capabilities> 5415 <parameters> 5416 <param id="object"> 5417 <jobject/> 5418 <description> 5419 The object 5420 </description> 5421 </param> 5422 <param id="object_reference_callback"> 5423 <ptrtype> 5424 <struct>jvmtiObjectReferenceCallback</struct> 5425 </ptrtype> 5426 <description> 5427 The callback to be called to describe each 5428 object reference. 5429 </description> 5430 </param> 5431 <param id="user_data"> 5432 <inbuf> 5433 <void/> 5434 <nullok><code>NULL</code> is passed as the user supplied data</nullok> 5435 </inbuf> 5436 <description> 5437 User supplied data to be passed to the callback. 5438 </description> 5439 </param> 5440 </parameters> 5441 <errors> 5442 </errors> 5443 </function> 5444 5445 <function id="IterateOverReachableObjects" num="110"> 5446 <synopsis>Iterate Over Reachable Objects</synopsis> 5447 <description> 5448 This function iterates over the root objects and all objects that 5449 are directly and indirectly reachable from the root objects. 5450 The root objects comprise the set of system classes, 5451 JNI globals, references from thread stacks, and other objects used as roots 5452 for the purposes of garbage collection. 5453 <p/> 5454 For each root the <paramlink id="heap_root_callback"></paramlink> 5455 or <paramlink id="stack_ref_callback"></paramlink> callback is called. 5456 An object can be a root object for more than one reason and in that case 5457 the appropriate callback is called for each reason. 5458 <p/> 5459 For each object reference the <paramlink id="object_ref_callback"></paramlink> 5460 callback function is called to describe the object reference. 5461 The callback is called exactly once for each reference from a referrer; 5462 this is true even if there are reference cycles or multiple paths to 5463 the referrer. 5464 There may be more than one reference between a referrer and a referree, 5465 These may be distinguished by the 5466 <datalink id="jvmtiObjectReferenceCallback.reference_kind"></datalink> and 5467 <datalink id="jvmtiObjectReferenceCallback.referrer_index"></datalink>. 5468 The callback for an object will always occur after the callback for 5469 its referrer. 5470 <p/> 5471 See <functionlink id="FollowReferences"/> for the object 5472 references which are reported. 5473 <p/> 5474 Roots are always reported to the profiler before any object references 5475 are reported. In other words, the <paramlink id="object_ref_callback"></paramlink> 5476 callback will not be called until the appropriate callback has been called 5477 for all roots. If the <paramlink id="object_ref_callback"></paramlink> callback is 5478 specified as <code>NULL</code> then this function returns after 5479 reporting the root objects to the profiler. 5480 <p/> 5481 During the execution of this function the state of the heap 5482 does not change: no objects are allocated, no objects are 5483 garbage collected, and the state of objects (including 5484 held values) does not change. 5485 As a result, threads executing Java 5486 programming language code, threads attempting to resume the 5487 execution of Java programming language code, and threads 5488 attempting to execute JNI functions are typically stalled. 5489 </description> 5490 <origin>new</origin> 5491 <capabilities> 5492 <required id="can_tag_objects"></required> 5493 </capabilities> 5494 <parameters> 5495 <param id="heap_root_callback"> 5496 <ptrtype> 5497 <struct>jvmtiHeapRootCallback</struct> 5498 <nullok>do not report heap roots</nullok> 5499 </ptrtype> 5500 <description> 5501 The callback function to be called for each heap root of type 5502 <code>JVMTI_HEAP_ROOT_JNI_GLOBAL</code>, 5503 <code>JVMTI_HEAP_ROOT_SYSTEM_CLASS</code>, 5504 <code>JVMTI_HEAP_ROOT_MONITOR</code>, 5505 <code>JVMTI_HEAP_ROOT_THREAD</code>, or 5506 <code>JVMTI_HEAP_ROOT_OTHER</code>. 5507 </description> 5508 </param> 5509 <param id="stack_ref_callback"> 5510 <ptrtype> 5511 <struct>jvmtiStackReferenceCallback</struct> 5512 <nullok>do not report stack references</nullok> 5513 </ptrtype> 5514 <description> 5515 The callback function to be called for each heap root of 5516 <code>JVMTI_HEAP_ROOT_STACK_LOCAL</code> or 5517 <code>JVMTI_HEAP_ROOT_JNI_LOCAL</code>. 5518 </description> 5519 </param> 5520 <param id="object_ref_callback"> 5521 <ptrtype> 5522 <struct>jvmtiObjectReferenceCallback</struct> 5523 <nullok>do not follow references from the root objects</nullok> 5524 </ptrtype> 5525 <description> 5526 The callback function to be called for each object reference. 5527 </description> 5528 </param> 5529 <param id="user_data"> 5530 <inbuf> 5531 <void/> 5532 <nullok><code>NULL</code> is passed as the user supplied data</nullok> 5533 </inbuf> 5534 <description> 5535 User supplied data to be passed to the callback. 5536 </description> 5537 </param> 5538 </parameters> 5539 <errors> 5540 </errors> 5541 </function> 5542 5543 <function id="IterateOverHeap" num="111"> 5544 <synopsis>Iterate Over Heap</synopsis> 5545 <description> 5546 Iterate over all objects in the heap. This includes both reachable and 5547 unreachable objects. 5548 <p/> 5549 The <paramlink id="object_filter"></paramlink> parameter indicates the 5550 objects for which the callback function is called. If this parameter 5551 is <code>JVMTI_HEAP_OBJECT_TAGGED</code> then the callback will only be 5552 called for every object that is tagged. If the parameter is 5553 <code>JVMTI_HEAP_OBJECT_UNTAGGED</code> then the callback will only be 5554 for objects that are not tagged. If the parameter 5555 is <code>JVMTI_HEAP_OBJECT_EITHER</code> then the callback will be 5556 called for every object in the heap, irrespective of whether it is 5557 tagged or not. 5558 <p/> 5559 During the execution of this function the state of the heap 5560 does not change: no objects are allocated, no objects are 5561 garbage collected, and the state of objects (including 5562 held values) does not change. 5563 As a result, threads executing Java 5564 programming language code, threads attempting to resume the 5565 execution of Java programming language code, and threads 5566 attempting to execute JNI functions are typically stalled. 5567 </description> 5568 <origin>new</origin> 5569 <capabilities> 5570 <required id="can_tag_objects"></required> 5571 </capabilities> 5572 <parameters> 5573 <param id="object_filter"> 5574 <enum>jvmtiHeapObjectFilter</enum> 5575 <description> 5576 Indicates the objects for which the callback function is called. 5577 </description> 5578 </param> 5579 <param id="heap_object_callback"> 5580 <ptrtype> 5581 <struct>jvmtiHeapObjectCallback</struct> 5582 </ptrtype> 5583 <description> 5584 The iterator function to be called for each 5585 object matching the <paramlink id="object_filter"/>. 5586 </description> 5587 </param> 5588 <param id="user_data"> 5589 <inbuf> 5590 <void/> 5591 <nullok><code>NULL</code> is passed as the user supplied data</nullok> 5592 </inbuf> 5593 <description> 5594 User supplied data to be passed to the callback. 5595 </description> 5596 </param> 5597 </parameters> 5598 <errors> 5599 </errors> 5600 </function> 5601 5602 <function id="IterateOverInstancesOfClass" num="112"> 5603 <synopsis>Iterate Over Instances Of Class</synopsis> 5604 <description> 5605 Iterate over all objects in the heap that are instances of the specified class. 5606 This includes direct instances of the specified class and 5607 instances of all subclasses of the specified class. 5608 This includes both reachable and unreachable objects. 5609 <p/> 5610 The <paramlink id="object_filter"></paramlink> parameter indicates the 5611 objects for which the callback function is called. If this parameter 5612 is <code>JVMTI_HEAP_OBJECT_TAGGED</code> then the callback will only be 5613 called for every object that is tagged. If the parameter is 5614 <code>JVMTI_HEAP_OBJECT_UNTAGGED</code> then the callback will only be 5615 called for objects that are not tagged. If the parameter 5616 is <code>JVMTI_HEAP_OBJECT_EITHER</code> then the callback will be 5617 called for every object in the heap, irrespective of whether it is 5618 tagged or not. 5619 <p/> 5620 During the execution of this function the state of the heap 5621 does not change: no objects are allocated, no objects are 5622 garbage collected, and the state of objects (including 5623 held values) does not change. 5624 As a result, threads executing Java 5625 programming language code, threads attempting to resume the 5626 execution of Java programming language code, and threads 5627 attempting to execute JNI functions are typically stalled. 5628 </description> 5629 <origin>new</origin> 5630 <capabilities> 5631 <required id="can_tag_objects"></required> 5632 </capabilities> 5633 <parameters> 5634 <param id="klass"> 5635 <jclass/> 5636 <description> 5637 Iterate over objects of this class only. 5638 </description> 5639 </param> 5640 <param id="object_filter"> 5641 <enum>jvmtiHeapObjectFilter</enum> 5642 <description> 5643 Indicates the objects for which the callback function is called. 5644 </description> 5645 </param> 5646 <param id="heap_object_callback"> 5647 <ptrtype> 5648 <struct>jvmtiHeapObjectCallback</struct> 5649 </ptrtype> 5650 <description> 5651 The iterator function to be called for each 5652 <paramlink id="klass"/> instance matching 5653 the <paramlink id="object_filter"/>. 5654 </description> 5655 </param> 5656 <param id="user_data"> 5657 <inbuf> 5658 <void/> 5659 <nullok><code>NULL</code> is passed as the user supplied data</nullok> 5660 </inbuf> 5661 <description> 5662 User supplied data to be passed to the callback. 5663 </description> 5664 </param> 5665 </parameters> 5666 <errors> 5667 </errors> 5668 </function> 5669 5670 </category> 5671 5672 <category id="local" label="Local Variable"> 5673 5674 <intro> 5675 These functions are used to retrieve or set the value of a local variable. 5676 The variable is identified by the depth of the frame containing its 5677 value and the variable's slot number within that frame. 5678 The mapping of variables to 5679 slot numbers can be obtained with the function 5680 <functionlink id="GetLocalVariableTable"></functionlink>. 5681 </intro> 5682 5683 <function id="GetLocalObject" num="21"> 5684 <synopsis>Get Local Variable - Object</synopsis> 5685 <description> 5686 This function can be used to retrieve the value of a local 5687 variable whose type is <code>Object</code> or a subclass of <code>Object</code>. 5688 </description> 5689 <origin>jvmdi</origin> 5690 <capabilities> 5691 <required id="can_access_local_variables"></required> 5692 </capabilities> 5693 <parameters> 5694 <param id="thread"> 5695 <jthread null="current" frame="frame"/> 5696 <description> 5697 The thread of the frame containing the variable's value. 5698 </description> 5699 </param> 5700 <param id="depth"> 5701 <jframeID thread="thread"/> 5702 <description> 5703 The depth of the frame containing the variable's value. 5704 </description> 5705 </param> 5706 <param id="slot"> 5707 <jint/> 5708 <description> 5709 The variable's slot number. 5710 </description> 5711 </param> 5712 <param id="value_ptr"> 5713 <outptr><jobject/></outptr> 5714 <description> 5715 On return, points to the variable's value. 5716 </description> 5717 </param> 5718 </parameters> 5719 <errors> 5720 <error id="JVMTI_ERROR_INVALID_SLOT"> 5721 Invalid <code>slot</code>. 5722 </error> 5723 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 5724 The variable type is not 5725 <code>Object</code> or a subclass of <code>Object</code>. 5726 </error> 5727 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 5728 Not a visible frame 5729 </error> 5730 </errors> 5731 </function> 5732 5733 <function id="GetLocalInstance" num="155" since="1.2"> 5734 <synopsis>Get Local Instance</synopsis> 5735 <description> 5736 This function can be used to retrieve the value of the local object 5737 variable at slot 0 (the "<code>this</code>" object) from non-static 5738 frames. This function can retrieve the "<code>this</code>" object from 5739 native method frames, whereas <code>GetLocalObject()</code> would 5740 return <code>JVMTI_ERROR_OPAQUE_FRAME</code> in those cases. 5741 </description> 5742 <origin>new</origin> 5743 <capabilities> 5744 <required id="can_access_local_variables"></required> 5745 </capabilities> 5746 <parameters> 5747 <param id="thread"> 5748 <jthread null="current" frame="frame"/> 5749 <description> 5750 The thread of the frame containing the variable's value. 5751 </description> 5752 </param> 5753 <param id="depth"> 5754 <jframeID thread="thread"/> 5755 <description> 5756 The depth of the frame containing the variable's value. 5757 </description> 5758 </param> 5759 <param id="value_ptr"> 5760 <outptr><jobject/></outptr> 5761 <description> 5762 On return, points to the variable's value. 5763 </description> 5764 </param> 5765 </parameters> 5766 <errors> 5767 <error id="JVMTI_ERROR_INVALID_SLOT"> 5768 If the specified frame is a static method frame. 5769 </error> 5770 </errors> 5771 </function> 5772 <function id="GetLocalInt" num="22"> 5773 <synopsis>Get Local Variable - Int</synopsis> 5774 <description> 5775 This function can be used to retrieve the value of a local 5776 variable whose type is <code>int</code>, 5777 <code>short</code>, <code>char</code>, <code>byte</code>, or 5778 <code>boolean</code>. 5779 </description> 5780 <origin>jvmdi</origin> 5781 <capabilities> 5782 <required id="can_access_local_variables"></required> 5783 </capabilities> 5784 <parameters> 5785 <param id="thread"> 5786 <jthread null="current" frame="frame"/> 5787 <description> 5788 The thread of the frame containing the variable's value. 5789 </description> 5790 </param> 5791 <param id="depth"> 5792 <jframeID thread="thread"/> 5793 <description> 5794 The depth of the frame containing the variable's value. 5795 </description> 5796 </param> 5797 <param id="slot"> 5798 <jint/> 5799 <description> 5800 The variable's slot number. 5801 </description> 5802 </param> 5803 <param id="value_ptr"> 5804 <outptr><jint/></outptr> 5805 <description> 5806 On return, points to the variable's value. 5807 </description> 5808 </param> 5809 </parameters> 5810 <errors> 5811 <error id="JVMTI_ERROR_INVALID_SLOT"> 5812 Invalid <code>slot</code>. 5813 </error> 5814 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 5815 The variable type is not 5816 <code>int</code>, <code>short</code>, 5817 <code>char</code>, <code>byte</code>, or 5818 <code>boolean</code>. 5819 </error> 5820 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 5821 Not a visible frame 5822 </error> 5823 </errors> 5824 </function> 5825 5826 <function id="GetLocalLong" num="23"> 5827 <synopsis>Get Local Variable - Long</synopsis> 5828 <description> 5829 This function can be used to retrieve the value of a local 5830 variable whose type is <code>long</code>. 5831 </description> 5832 <origin>jvmdi</origin> 5833 <capabilities> 5834 <required id="can_access_local_variables"></required> 5835 </capabilities> 5836 <parameters> 5837 <param id="thread"> 5838 <jthread null="current" frame="frame"/> 5839 <description> 5840 The thread of the frame containing the variable's value. 5841 </description> 5842 </param> 5843 <param id="depth"> 5844 <jframeID thread="thread"/> 5845 <description> 5846 The depth of the frame containing the variable's value. 5847 </description> 5848 </param> 5849 <param id="slot"> 5850 <jint/> 5851 <description> 5852 The variable's slot number. 5853 </description> 5854 </param> 5855 <param id="value_ptr"> 5856 <outptr><jlong/></outptr> 5857 <description> 5858 On return, points to the variable's value. 5859 </description> 5860 </param> 5861 </parameters> 5862 <errors> 5863 <error id="JVMTI_ERROR_INVALID_SLOT"> 5864 Invalid <code>slot</code>. 5865 </error> 5866 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 5867 The variable type is not <code>long</code>. 5868 </error> 5869 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 5870 Not a visible frame 5871 </error> 5872 </errors> 5873 </function> 5874 5875 <function id="GetLocalFloat" num="24"> 5876 <synopsis>Get Local Variable - Float</synopsis> 5877 <description> 5878 This function can be used to retrieve the value of a local 5879 variable whose type is <code>float</code>. 5880 </description> 5881 <origin>jvmdi</origin> 5882 <capabilities> 5883 <required id="can_access_local_variables"></required> 5884 </capabilities> 5885 <parameters> 5886 <param id="thread"> 5887 <jthread null="current" frame="frame"/> 5888 <description> 5889 The thread of the frame containing the variable's value. 5890 </description> 5891 </param> 5892 <param id="depth"> 5893 <jframeID thread="thread"/> 5894 <description> 5895 The depth of the frame containing the variable's value. 5896 </description> 5897 </param> 5898 <param id="slot"> 5899 <jint/> 5900 <description> 5901 The variable's slot number. 5902 </description> 5903 </param> 5904 <param id="value_ptr"> 5905 <outptr><jfloat/></outptr> 5906 <description> 5907 On return, points to the variable's value. 5908 </description> 5909 </param> 5910 </parameters> 5911 <errors> 5912 <error id="JVMTI_ERROR_INVALID_SLOT"> 5913 Invalid <code>slot</code>. 5914 </error> 5915 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 5916 The variable type is not <code>float</code>. 5917 </error> 5918 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 5919 Not a visible frame 5920 </error> 5921 </errors> 5922 </function> 5923 5924 <function id="GetLocalDouble" num="25"> 5925 <synopsis>Get Local Variable - Double</synopsis> 5926 <description> 5927 This function can be used to retrieve the value of a local 5928 variable whose type is <code>long</code>. 5929 </description> 5930 <origin>jvmdi</origin> 5931 <capabilities> 5932 <required id="can_access_local_variables"></required> 5933 </capabilities> 5934 <parameters> 5935 <param id="thread"> 5936 <jthread null="current" frame="frame"/> 5937 <description> 5938 The thread of the frame containing the variable's value. 5939 </description> 5940 </param> 5941 <param id="depth"> 5942 <jframeID thread="thread"/> 5943 <description> 5944 The depth of the frame containing the variable's value. 5945 </description> 5946 </param> 5947 <param id="slot"> 5948 <jint/> 5949 <description> 5950 The variable's slot number. 5951 </description> 5952 </param> 5953 <param id="value_ptr"> 5954 <outptr><jdouble/></outptr> 5955 <description> 5956 On return, points to the variable's value. 5957 </description> 5958 </param> 5959 </parameters> 5960 <errors> 5961 <error id="JVMTI_ERROR_INVALID_SLOT"> 5962 Invalid <code>slot</code>. 5963 </error> 5964 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 5965 The variable type is not <code>double</code>. 5966 </error> 5967 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 5968 Not a visible frame 5969 </error> 5970 </errors> 5971 </function> 5972 5973 <function id="SetLocalObject" num="26"> 5974 <synopsis>Set Local Variable - Object</synopsis> 5975 <description> 5976 This function can be used to set the value of a local 5977 variable whose type is <code>Object</code> or a subclass of <code>Object</code>. 5978 </description> 5979 <origin>jvmdi</origin> 5980 <capabilities> 5981 <required id="can_access_local_variables"></required> 5982 </capabilities> 5983 <parameters> 5984 <param id="thread"> 5985 <jthread null="current" frame="frame"/> 5986 <description> 5987 The thread of the frame containing the variable's value. 5988 </description> 5989 </param> 5990 <param id="depth"> 5991 <jframeID thread="thread"/> 5992 <description> 5993 The depth of the frame containing the variable's value. 5994 </description> 5995 </param> 5996 <param id="slot"> 5997 <jint/> 5998 <description> 5999 The variable's slot number. 6000 </description> 6001 </param> 6002 <param id="value"> 6003 <jobject/> 6004 <description> 6005 The new value for the variable. 6006 </description> 6007 </param> 6008 </parameters> 6009 <errors> 6010 <error id="JVMTI_ERROR_INVALID_SLOT"> 6011 Invalid <code>slot</code>. 6012 </error> 6013 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 6014 The variable type is not 6015 <code>Object</code> or a subclass of <code>Object</code>. 6016 </error> 6017 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 6018 The supplied <paramlink id="value"/> is not compatible 6019 with the variable type. 6020 </error> 6021 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 6022 Not a visible frame 6023 </error> 6024 </errors> 6025 </function> 6026 6027 <function id="SetLocalInt" num="27"> 6028 <synopsis>Set Local Variable - Int</synopsis> 6029 <description> 6030 This function can be used to set the value of a local 6031 variable whose type is <code>int</code>, 6032 <code>short</code>, <code>char</code>, <code>byte</code>, or 6033 <code>boolean</code>. 6034 </description> 6035 <origin>jvmdi</origin> 6036 <capabilities> 6037 <required id="can_access_local_variables"></required> 6038 </capabilities> 6039 <parameters> 6040 <param id="thread"> 6041 <jthread null="current" frame="frame"/> 6042 <description> 6043 The thread of the frame containing the variable's value. 6044 </description> 6045 </param> 6046 <param id="depth"> 6047 <jframeID thread="thread"/> 6048 <description> 6049 The depth of the frame containing the variable's value. 6050 </description> 6051 </param> 6052 <param id="slot"> 6053 <jint/> 6054 <description> 6055 The variable's slot number. 6056 </description> 6057 </param> 6058 <param id="value"> 6059 <jint/> 6060 <description> 6061 The new value for the variable. 6062 </description> 6063 </param> 6064 </parameters> 6065 <errors> 6066 <error id="JVMTI_ERROR_INVALID_SLOT"> 6067 Invalid <code>slot</code>. 6068 </error> 6069 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 6070 The variable type is not 6071 <code>int</code>, <code>short</code>, 6072 <code>char</code>, <code>byte</code>, or 6073 <code>boolean</code>. 6074 </error> 6075 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 6076 Not a visible frame 6077 </error> 6078 </errors> 6079 </function> 6080 6081 <function id="SetLocalLong" num="28"> 6082 <synopsis>Set Local Variable - Long</synopsis> 6083 <description> 6084 This function can be used to set the value of a local 6085 variable whose type is <code>long</code>. 6086 </description> 6087 <origin>jvmdi</origin> 6088 <capabilities> 6089 <required id="can_access_local_variables"></required> 6090 </capabilities> 6091 <parameters> 6092 <param id="thread"> 6093 <jthread null="current" frame="frame"/> 6094 <description> 6095 The thread of the frame containing the variable's value. 6096 </description> 6097 </param> 6098 <param id="depth"> 6099 <jframeID thread="thread"/> 6100 <description> 6101 The depth of the frame containing the variable's value. 6102 </description> 6103 </param> 6104 <param id="slot"> 6105 <jint/> 6106 <description> 6107 The variable's slot number. 6108 </description> 6109 </param> 6110 <param id="value"> 6111 <jlong/> 6112 <description> 6113 The new value for the variable. 6114 </description> 6115 </param> 6116 </parameters> 6117 <errors> 6118 <error id="JVMTI_ERROR_INVALID_SLOT"> 6119 Invalid <code>slot</code>. 6120 </error> 6121 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 6122 The variable type is not <code>long</code>. 6123 </error> 6124 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 6125 Not a visible frame 6126 </error> 6127 </errors> 6128 </function> 6129 6130 <function id="SetLocalFloat" num="29"> 6131 <synopsis>Set Local Variable - Float</synopsis> 6132 <description> 6133 This function can be used to set the value of a local 6134 variable whose type is <code>float</code>. 6135 </description> 6136 <origin>jvmdi</origin> 6137 <capabilities> 6138 <required id="can_access_local_variables"></required> 6139 </capabilities> 6140 <parameters> 6141 <param id="thread"> 6142 <jthread null="current" frame="frame"/> 6143 <description> 6144 The thread of the frame containing the variable's value. 6145 </description> 6146 </param> 6147 <param id="depth"> 6148 <jframeID thread="thread"/> 6149 <description> 6150 The depth of the frame containing the variable's value. 6151 </description> 6152 </param> 6153 <param id="slot"> 6154 <jint/> 6155 <description> 6156 The variable's slot number. 6157 </description> 6158 </param> 6159 <param id="value"> 6160 <jfloat/> 6161 <description> 6162 The new value for the variable. 6163 </description> 6164 </param> 6165 </parameters> 6166 <errors> 6167 <error id="JVMTI_ERROR_INVALID_SLOT"> 6168 Invalid <code>slot</code>. 6169 </error> 6170 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 6171 The variable type is not <code>float</code>. 6172 </error> 6173 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 6174 Not a visible frame 6175 </error> 6176 </errors> 6177 </function> 6178 6179 <function id="SetLocalDouble" num="30"> 6180 <synopsis>Set Local Variable - Double</synopsis> 6181 <description> 6182 This function can be used to set the value of a local 6183 variable whose type is <code>double</code>. 6184 </description> 6185 <origin>jvmdi</origin> 6186 <capabilities> 6187 <required id="can_access_local_variables"></required> 6188 </capabilities> 6189 <parameters> 6190 <param id="thread"> 6191 <jthread null="current" frame="frame"/> 6192 <description> 6193 The thread of the frame containing the variable's value. 6194 </description> 6195 </param> 6196 <param id="depth"> 6197 <jframeID thread="thread"/> 6198 <description> 6199 The depth of the frame containing the variable's value. 6200 </description> 6201 </param> 6202 <param id="slot"> 6203 <jint/> 6204 <description> 6205 The variable's slot number. 6206 </description> 6207 </param> 6208 <param id="value"> 6209 <jdouble/> 6210 <description> 6211 The new value for the variable. 6212 </description> 6213 </param> 6214 </parameters> 6215 <errors> 6216 <error id="JVMTI_ERROR_INVALID_SLOT"> 6217 Invalid <code>slot</code>. 6218 </error> 6219 <error id="JVMTI_ERROR_TYPE_MISMATCH"> 6220 The variable type is not <code>double</code>. 6221 </error> 6222 <error id="JVMTI_ERROR_OPAQUE_FRAME"> 6223 Not a visible frame 6224 </error> 6225 </errors> 6226 </function> 6227 </category> 6228 6229 <category id="breakpointCategory" label="Breakpoint"> 6230 6231 <intro> 6232 </intro> 6233 6234 <function id="SetBreakpoint" num="38"> 6235 <synopsis>Set Breakpoint</synopsis> 6236 <description> 6237 Set a breakpoint at the instruction indicated by 6238 <code>method</code> and <code>location</code>. 6239 An instruction can only have one breakpoint. 6240 <p/> 6241 Whenever the designated instruction is about to be executed, a 6242 <eventlink id="Breakpoint"></eventlink> event is generated. 6243 </description> 6244 <origin>jvmdi</origin> 6245 <capabilities> 6246 <required id="can_generate_breakpoint_events"></required> 6247 </capabilities> 6248 <parameters> 6249 <param id="klass"> 6250 <jclass method="method"/> 6251 <description> 6252 The class in which to set the breakpoint 6253 </description> 6254 </param> 6255 <param id="method"> 6256 <jmethodID class="klass"/> 6257 <description> 6258 The method in which to set the breakpoint 6259 </description> 6260 </param> 6261 <param id="location"> 6262 <jlocation/> 6263 <description> 6264 the index of the instruction at which to set the breakpoint 6265 6266 </description> 6267 </param> 6268 </parameters> 6269 <errors> 6270 <error id="JVMTI_ERROR_DUPLICATE"> 6271 The designated bytecode already has a breakpoint. 6272 </error> 6273 </errors> 6274 </function> 6275 6276 <function id="ClearBreakpoint" num="39"> 6277 <synopsis>Clear Breakpoint</synopsis> 6278 <description> 6279 Clear the breakpoint at the bytecode indicated by 6280 <code>method</code> and <code>location</code>. 6281 </description> 6282 <origin>jvmdi</origin> 6283 <capabilities> 6284 <required id="can_generate_breakpoint_events"></required> 6285 </capabilities> 6286 <parameters> 6287 <param id="klass"> 6288 <jclass method="method"/> 6289 <description> 6290 The class in which to clear the breakpoint 6291 </description> 6292 </param> 6293 <param id="method"> 6294 <jmethodID class="klass"/> 6295 <description> 6296 The method in which to clear the breakpoint 6297 </description> 6298 </param> 6299 <param id="location"> 6300 <jlocation/> 6301 <description> 6302 the index of the instruction at which to clear the breakpoint 6303 </description> 6304 </param> 6305 </parameters> 6306 <errors> 6307 <error id="JVMTI_ERROR_NOT_FOUND"> 6308 There's no breakpoint at the designated bytecode. 6309 </error> 6310 </errors> 6311 </function> 6312 6313 </category> 6314 6315 <category id="fieldWatch" label="Watched Field"> 6316 6317 <intro> 6318 </intro> 6319 6320 <function id="SetFieldAccessWatch" num="41"> 6321 <synopsis>Set Field Access Watch</synopsis> 6322 <description> 6323 Generate a <eventlink id="FieldAccess"></eventlink> event 6324 when the field specified 6325 by <code>klass</code> and 6326 <code>field</code> is about to be accessed. 6327 An event will be generated for each access of the field 6328 until it is canceled with 6329 <functionlink id="ClearFieldAccessWatch"></functionlink>. 6330 Field accesses from Java programming language code or from JNI code are watched, 6331 fields modified by other means are not watched. 6332 Note that <jvmti/> users should be aware that their own field accesses 6333 will trigger the watch. 6334 A field can only have one field access watch set. 6335 Modification of a field is not considered an access--use 6336 <functionlink id="SetFieldModificationWatch"></functionlink> 6337 to monitor modifications. 6338 </description> 6339 <origin>jvmdi</origin> 6340 <capabilities> 6341 <required id="can_generate_field_access_events"></required> 6342 </capabilities> 6343 <parameters> 6344 <param id="klass"> 6345 <jclass field="field"/> 6346 <description> 6347 The class containing the field to watch 6348 </description> 6349 </param> 6350 <param id="field"> 6351 <jfieldID class="klass"/> 6352 <description> 6353 The field to watch 6354 6355 </description> 6356 </param> 6357 </parameters> 6358 <errors> 6359 <error id="JVMTI_ERROR_DUPLICATE"> 6360 The designated field is already being watched for accesses. 6361 </error> 6362 </errors> 6363 </function> 6364 6365 <function id="ClearFieldAccessWatch" num="42"> 6366 <synopsis>Clear Field Access Watch</synopsis> 6367 <description> 6368 Cancel a field access watch previously set by 6369 <functionlink id="SetFieldAccessWatch"></functionlink>, on the 6370 field specified 6371 by <code>klass</code> and 6372 <code>field</code>. 6373 </description> 6374 <origin>jvmdi</origin> 6375 <capabilities> 6376 <required id="can_generate_field_access_events"></required> 6377 </capabilities> 6378 <parameters> 6379 <param id="klass"> 6380 <jclass field="field"/> 6381 <description> 6382 The class containing the field to watch 6383 </description> 6384 </param> 6385 <param id="field"> 6386 <jfieldID class="klass"/> 6387 <description> 6388 The field to watch 6389 6390 </description> 6391 </param> 6392 </parameters> 6393 <errors> 6394 <error id="JVMTI_ERROR_NOT_FOUND"> 6395 The designated field is not being watched for accesses. 6396 </error> 6397 </errors> 6398 </function> 6399 6400 <function id="SetFieldModificationWatch" num="43"> 6401 <synopsis>Set Field Modification Watch</synopsis> 6402 <description> 6403 Generate a <eventlink id="FieldModification"></eventlink> event 6404 when the field specified 6405 by <code>klass</code> and 6406 <code>field</code> is about to be modified. 6407 An event will be generated for each modification of the field 6408 until it is canceled with 6409 <functionlink id="ClearFieldModificationWatch"></functionlink>. 6410 Field modifications from Java programming language code or from JNI code are watched, 6411 fields modified by other means are not watched. 6412 Note that <jvmti/> users should be aware that their own field modifications 6413 will trigger the watch. 6414 A field can only have one field modification watch set. 6415 </description> 6416 <origin>jvmdi</origin> 6417 <capabilities> 6418 <required id="can_generate_field_modification_events"></required> 6419 </capabilities> 6420 <parameters> 6421 <param id="klass"> 6422 <jclass field="field"/> 6423 <description> 6424 The class containing the field to watch 6425 </description> 6426 </param> 6427 <param id="field"> 6428 <jfieldID class="klass"/> 6429 <description> 6430 The field to watch 6431 6432 </description> 6433 </param> 6434 </parameters> 6435 <errors> 6436 <error id="JVMTI_ERROR_DUPLICATE"> 6437 The designated field is already being watched for modifications. 6438 </error> 6439 </errors> 6440 </function> 6441 6442 <function id="ClearFieldModificationWatch" num="44"> 6443 <synopsis>Clear Field Modification Watch</synopsis> 6444 <description> 6445 6446 Cancel a field modification watch previously set by 6447 <functionlink id="SetFieldModificationWatch"></functionlink>, on the 6448 field specified 6449 by <code>klass</code> and 6450 <code>field</code>. 6451 </description> 6452 <origin>jvmdi</origin> 6453 <capabilities> 6454 <required id="can_generate_field_modification_events"></required> 6455 </capabilities> 6456 <parameters> 6457 <param id="klass"> 6458 <jclass field="field"/> 6459 <description> 6460 The class containing the field to watch 6461 </description> 6462 </param> 6463 <param id="field"> 6464 <jfieldID class="klass"/> 6465 <description> 6466 The field to watch 6467 6468 </description> 6469 </param> 6470 </parameters> 6471 <errors> 6472 <error id="JVMTI_ERROR_NOT_FOUND"> 6473 The designated field is not being watched for modifications. 6474 </error> 6475 </errors> 6476 </function> 6477 </category> 6478 6479 <category id="module" label="Module"> 6480 6481 <intro> 6482 </intro> 6483 6484 <function id="GetAllModules" num="3" since="9"> 6485 <synopsis>Get All Modules</synopsis> 6486 <description> 6487 Return an array of all modules loaded in the virtual machine. 6488 The array includes the unnamed module for each class loader. 6489 The number of modules in the array is returned via 6490 <code>module_count_ptr</code>, and the array itself via 6491 <code>modules_ptr</code>. 6492 <p/> 6493 </description> 6494 <origin>new</origin> 6495 <capabilities> 6496 </capabilities> 6497 <parameters> 6498 <param id="module_count_ptr"> 6499 <outptr><jint/></outptr> 6500 <description> 6501 On return, points to the number of returned modules. 6502 </description> 6503 </param> 6504 <param id="modules_ptr"> 6505 <allocbuf outcount="module_count_ptr"><jobject/></allocbuf> 6506 <description> 6507 On return, points to an array of references, one 6508 for each module. 6509 </description> 6510 </param> 6511 </parameters> 6512 <errors> 6513 </errors> 6514 </function> 6515 6516 <function id="GetNamedModule" num="40" since="9"> 6517 <synopsis>Get Named Module</synopsis> 6518 <description> 6519 Return the <code>java.lang.Module</code> object for a named 6520 module defined to a class loader that contains a given package. 6521 The module is returned via <code>module_ptr</code>. 6522 <p/> 6523 If a named module is defined to the class loader and it 6524 contains the package then that named module is returned, 6525 otherwise <code>NULL</code> is returned. 6526 <p/> 6527 </description> 6528 <origin>new</origin> 6529 <capabilities> 6530 </capabilities> 6531 <parameters> 6532 <param id="class_loader"> 6533 <ptrtype> 6534 <jobject/> 6535 <nullok>the bootstrap loader is assumed</nullok> 6536 </ptrtype> 6537 <description> 6538 A class loader. 6539 If the <code>class_loader</code> is not <code>NULL</code> 6540 or a subclass of <code>java.lang.ClassLoader</code> 6541 this function returns 6542 <errorlink id="JVMTI_ERROR_ILLEGAL_ARGUMENT"></errorlink>. 6543 </description> 6544 </param> 6545 <param id="package_name"> 6546 <inbuf><char/></inbuf> 6547 <description> 6548 The name of the package, encoded as a 6549 <internallink id="mUTF">modified UTF-8</internallink> string. 6550 The package name is in internal form (JVMS 4.2.1); 6551 identifiers are separated by forward slashes rather than periods. 6552 </description> 6553 </param> 6554 <param id="module_ptr"> 6555 <outptr><jobject/></outptr> 6556 <description> 6557 On return, points to a <code>java.lang.Module</code> object 6558 or points to <code>NULL</code>. 6559 </description> 6560 </param> 6561 </parameters> 6562 <errors> 6563 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 6564 If class loader is not <code>NULL</code> and is not a class loader object. 6565 </error> 6566 </errors> 6567 </function> 6568 6569 <function id="AddModuleReads" num="94" since="9"> 6570 <synopsis>Add Module Reads</synopsis> 6571 <description> 6572 Update a module to read another module. This function is a no-op 6573 when <paramlink id="module"></paramlink> is an unnamed module. 6574 This function facilitates the instrumentation of code 6575 in named modules where that instrumentation requires 6576 expanding the set of modules that a module reads. 6577 </description> 6578 <origin>new</origin> 6579 <capabilities> 6580 </capabilities> 6581 <parameters> 6582 <param id="module"> 6583 <ptrtype><jobject/></ptrtype> 6584 <description> 6585 The module to update. 6586 </description> 6587 </param> 6588 <param id="to_module"> 6589 <ptrtype><jobject/></ptrtype> 6590 <description> 6591 The additional module to read. 6592 </description> 6593 </param> 6594 </parameters> 6595 <errors> 6596 <error id="JVMTI_ERROR_INVALID_MODULE"> 6597 If <paramlink id="module"></paramlink> is not a module object. 6598 </error> 6599 <error id="JVMTI_ERROR_INVALID_MODULE"> 6600 If <paramlink id="to_module"></paramlink> is not a module object. 6601 </error> 6602 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE"> 6603 if the module cannot be modified. 6604 See <functionlink id="IsModifiableModule"/>. 6605 </error> 6606 </errors> 6607 </function> 6608 6609 <function id="AddModuleExports" num="95" since="9"> 6610 <synopsis>Add Module Exports</synopsis> 6611 <description> 6612 Update a module to export a package to another module. 6613 This function is a no-op when <paramlink id="module"></paramlink> 6614 is an unnamed module or an open module. 6615 This function facilitates the instrumentation of code 6616 in named modules where that instrumentation requires 6617 expanding the set of packages that a module exports. 6618 </description> 6619 <origin>new</origin> 6620 <capabilities> 6621 </capabilities> 6622 <parameters> 6623 <param id="module"> 6624 <ptrtype><jobject/></ptrtype> 6625 <description> 6626 The module to update. 6627 </description> 6628 </param> 6629 <param id="pkg_name"> 6630 <inbuf><char/></inbuf> 6631 <description> 6632 The exported package name. 6633 </description> 6634 </param> 6635 <param id="to_module"> 6636 <ptrtype><jobject/></ptrtype> 6637 <description> 6638 The module the package is exported to. 6639 If the <code>to_module</code> is not a subclass of 6640 <code>java.lang.Module</code> this function returns 6641 <errorlink id="JVMTI_ERROR_INVALID_MODULE"></errorlink>. 6642 </description> 6643 </param> 6644 </parameters> 6645 <errors> 6646 <error id="JVMTI_ERROR_INVALID_MODULE"> 6647 If <paramlink id="module"></paramlink> is not a module object. 6648 </error> 6649 <error id="JVMTI_ERROR_INVALID_MODULE"> 6650 If <paramlink id="to_modules"></paramlink> is not a module object. 6651 </error> 6652 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 6653 If the package <paramlink id="pkg_name"></paramlink> 6654 does not belong to the module. 6655 </error> 6656 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE"> 6657 if the module cannot be modified. 6658 See <functionlink id="IsModifiableModule"/>. 6659 </error> 6660 </errors> 6661 </function> 6662 6663 <function id="AddModuleOpens" num="96" since="9"> 6664 <synopsis>Add Module Opens</synopsis> 6665 <description> 6666 Update a module to open a package to another module. 6667 This function is a no-op when <paramlink id="module"></paramlink> 6668 is an unnamed module or an open module. 6669 This function facilitates the instrumentation of code 6670 in modules where that instrumentation requires 6671 expanding the set of packages that a module opens to 6672 other modules. 6673 </description> 6674 <origin>new</origin> 6675 <capabilities> 6676 </capabilities> 6677 <parameters> 6678 <param id="module"> 6679 <ptrtype><jobject/></ptrtype> 6680 <description> 6681 The module to update. 6682 </description> 6683 </param> 6684 <param id="pkg_name"> 6685 <inbuf><char/></inbuf> 6686 <description> 6687 The package name of the package to open. 6688 </description> 6689 </param> 6690 <param id="to_module"> 6691 <ptrtype><jobject/></ptrtype> 6692 <description> 6693 The module with the package to open. 6694 If the <code>to_module</code> is not a subclass of 6695 <code>java.lang.Module</code> this function returns 6696 <errorlink id="JVMTI_ERROR_INVALID_MODULE"></errorlink>. 6697 </description> 6698 </param> 6699 </parameters> 6700 <errors> 6701 <error id="JVMTI_ERROR_INVALID_MODULE"> 6702 If <paramlink id="module"></paramlink> is not a module object. 6703 </error> 6704 <error id="JVMTI_ERROR_INVALID_MODULE"> 6705 If <paramlink id="to_modules"></paramlink> is not a module object. 6706 </error> 6707 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 6708 If the package <paramlink id="pkg_name"></paramlink> 6709 does not belong to the module. 6710 </error> 6711 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE"> 6712 if the module cannot be modified. 6713 See <functionlink id="IsModifiableModule"/>. 6714 </error> 6715 </errors> 6716 </function> 6717 6718 <function id="AddModuleUses" num="97" since="9"> 6719 <synopsis>Add Module Uses</synopsis> 6720 <description> 6721 Updates a module to add a service to the set of services that 6722 a module uses. This function is a no-op when the module 6723 is an unnamed module. 6724 This function facilitates the instrumentation of code 6725 in named modules where that instrumentation requires 6726 expanding the set of services that a module is using. 6727 </description> 6728 <origin>new</origin> 6729 <capabilities> 6730 </capabilities> 6731 <parameters> 6732 <param id="module"> 6733 <ptrtype><jobject/></ptrtype> 6734 <description> 6735 The module to update. 6736 </description> 6737 </param> 6738 <param id="service"> 6739 <ptrtype><jclass/></ptrtype> 6740 <description> 6741 The service to use. 6742 </description> 6743 </param> 6744 </parameters> 6745 <errors> 6746 <error id="JVMTI_ERROR_INVALID_MODULE"> 6747 If <paramlink id="module"></paramlink> is not a module object. 6748 </error> 6749 <error id="JVMTI_ERROR_INVALID_CLASS"> 6750 If <paramlink id="service"></paramlink> is not a class object. 6751 </error> 6752 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE"> 6753 if the module cannot be modified. 6754 See <functionlink id="IsModifiableModule"/>. 6755 </error> 6756 </errors> 6757 </function> 6758 6759 <function id="AddModuleProvides" num="98" since="9"> 6760 <synopsis>Add Module Provides</synopsis> 6761 <description> 6762 Updates a module to add a service to the set of services that 6763 a module provides. This function is a no-op when the module 6764 is an unnamed module. 6765 This function facilitates the instrumentation of code 6766 in named modules where that instrumentation requires 6767 changes to the services that are provided. 6768 </description> 6769 <origin>new</origin> 6770 <capabilities> 6771 </capabilities> 6772 <parameters> 6773 <param id="module"> 6774 <ptrtype><jobject/></ptrtype> 6775 <description> 6776 The module to update. 6777 </description> 6778 </param> 6779 <param id="service"> 6780 <ptrtype><jclass/></ptrtype> 6781 <description> 6782 The service to provide. 6783 </description> 6784 </param> 6785 <param id="impl_class"> 6786 <ptrtype><jclass/></ptrtype> 6787 <description> 6788 The implementation class for the provided service. 6789 </description> 6790 </param> 6791 </parameters> 6792 <errors> 6793 <error id="JVMTI_ERROR_INVALID_MODULE"> 6794 If <paramlink id="module"></paramlink> is not a module object. 6795 </error> 6796 <error id="JVMTI_ERROR_INVALID_CLASS"> 6797 If <paramlink id="service"></paramlink> is not a class object. 6798 </error> 6799 <error id="JVMTI_ERROR_INVALID_CLASS"> 6800 If <paramlink id="impl_class"></paramlink> is not a class object. 6801 </error> 6802 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE"> 6803 if the module cannot be modified. 6804 See <functionlink id="IsModifiableModule"/>. 6805 </error> 6806 </errors> 6807 </function> 6808 6809 <function id="IsModifiableModule" num="99" since="9"> 6810 <synopsis>Is Modifiable Module</synopsis> 6811 <description> 6812 Determines whether a module is modifiable. 6813 If a module is modifiable then this module can be updated with 6814 <functionlink id="AddModuleReads"/>, <functionlink id="AddModuleExports"/>, 6815 <functionlink id="AddModuleOpens"/>, <functionlink id="AddModuleUses"/>, 6816 and <functionlink id="AddModuleProvides"/>. If a module is not modifiable 6817 then the module can not be updated with these functions. The result of 6818 this function is always <code>JNI_TRUE</code> when called to determine 6819 if an unnamed module is modifiable. 6820 </description> 6821 <origin>new</origin> 6822 <capabilities> 6823 </capabilities> 6824 <parameters> 6825 <param id="module"> 6826 <ptrtype><jobject/></ptrtype> 6827 <description> 6828 The module to query. 6829 </description> 6830 </param> 6831 <param id="is_modifiable_module_ptr"> 6832 <outptr><jboolean/></outptr> 6833 <description> 6834 On return, points to the boolean result of this function. 6835 </description> 6836 </param> 6837 </parameters> 6838 <errors> 6839 <error id="JVMTI_ERROR_INVALID_MODULE"> 6840 If <paramlink id="module"></paramlink> is not a module object. 6841 </error> 6842 </errors> 6843 </function> 6844 6845 </category> 6846 6847 <category id="class" label="Class"> 6848 6849 <intro> 6850 </intro> 6851 6852 <function id="GetLoadedClasses" jkernel="yes" num="78"> 6853 <synopsis>Get Loaded Classes</synopsis> 6854 <description> 6855 Return an array of all classes loaded in the virtual machine. 6856 The number of classes in the array is returned via 6857 <code>class_count_ptr</code>, and the array itself via 6858 <code>classes_ptr</code>. 6859 <p/> 6860 Array classes of all types (including arrays of primitive types) are 6861 included in the returned list. Primitive classes (for example, 6862 <code>java.lang.Integer.TYPE</code>) are <i>not</i> included in this list. 6863 </description> 6864 <origin>jvmdi</origin> 6865 <capabilities> 6866 </capabilities> 6867 <parameters> 6868 <param id="class_count_ptr"> 6869 <outptr><jint/></outptr> 6870 <description> 6871 On return, points to the number of classes. 6872 </description> 6873 </param> 6874 <param id="classes_ptr"> 6875 <allocbuf outcount="class_count_ptr"><jclass/></allocbuf> 6876 <description> 6877 On return, points to an array of references, one 6878 for each class. 6879 </description> 6880 </param> 6881 </parameters> 6882 <errors> 6883 </errors> 6884 </function> 6885 6886 <function id="GetClassLoaderClasses" jkernel="yes" num="79"> 6887 <synopsis>Get Classloader Classes</synopsis> 6888 <description> 6889 Returns an array of those classes for which this class loader has 6890 been recorded as an initiating loader. Each 6891 class in the returned array was created by this class loader, 6892 either by defining it directly or by delegation to another class loader. 6893 See <vmspec chapter="5.3"/>. 6894 <p/> 6895 The number of classes in the array is returned via 6896 <code>class_count_ptr</code>, and the array itself via 6897 <code>classes_ptr</code>. 6898 </description> 6899 <origin>jvmdi</origin> 6900 <capabilities> 6901 </capabilities> 6902 <parameters> 6903 <param id="initiating_loader"> 6904 <ptrtype> 6905 <jobject/> 6906 <nullok>the classes initiated by the bootstrap loader will be returned</nullok> 6907 </ptrtype> 6908 <description> 6909 An initiating class loader. 6910 </description> 6911 </param> 6912 <param id="class_count_ptr"> 6913 <outptr><jint/></outptr> 6914 <description> 6915 On return, points to the number of classes. 6916 </description> 6917 </param> 6918 <param id="classes_ptr"> 6919 <allocbuf outcount="class_count_ptr"><jclass/></allocbuf> 6920 <description> 6921 On return, points to an array of references, one 6922 for each class. 6923 </description> 6924 </param> 6925 </parameters> 6926 <errors> 6927 </errors> 6928 </function> 6929 6930 <function id="GetClassSignature" phase="start" num="48"> 6931 <synopsis>Get Class Signature</synopsis> 6932 <description> 6933 For the class indicated by <code>klass</code>, return the 6934 <externallink id="jni/types.html#type-signatures">JNI 6935 type signature</externallink> 6936 and the generic signature of the class. 6937 For example, <code>java.util.List</code> is <code>"Ljava/util/List;"</code> 6938 and <code>int[]</code> is <code>"[I"</code> 6939 The returned name for primitive classes 6940 is the type signature character of the corresponding primitive type. 6941 For example, <code>java.lang.Integer.TYPE</code> is <code>"I"</code>. 6942 </description> 6943 <origin>jvmdiClone</origin> 6944 <capabilities> 6945 </capabilities> 6946 <parameters> 6947 <param id="klass"> 6948 <jclass/> 6949 <description> 6950 The class to query. 6951 </description> 6952 </param> 6953 <param id="signature_ptr"> 6954 <allocbuf> 6955 <char/> 6956 <nullok>the signature is not returned</nullok> 6957 </allocbuf> 6958 <description> 6959 On return, points to the JNI type signature of the class, encoded as a 6960 <internallink id="mUTF">modified UTF-8</internallink> string. 6961 </description> 6962 </param> 6963 <param id="generic_ptr"> 6964 <allocbuf> 6965 <char/> 6966 <nullok>the generic signature is not returned</nullok> 6967 </allocbuf> 6968 <description> 6969 On return, points to the generic signature of the class, encoded as a 6970 <internallink id="mUTF">modified UTF-8</internallink> string. 6971 If there is no generic signature attribute for the class, then, 6972 on return, points to <code>NULL</code>. 6973 </description> 6974 </param> 6975 </parameters> 6976 <errors> 6977 </errors> 6978 </function> 6979 6980 <function id="GetClassStatus" phase="start" num="49"> 6981 <synopsis>Get Class Status</synopsis> 6982 <description> 6983 Get the status of the class. Zero or more of the following bits can be 6984 set. 6985 <constants id="jvmtiClassStatus" label="Class Status Flags" kind="bits"> 6986 <constant id="JVMTI_CLASS_STATUS_VERIFIED" num="1"> 6987 Class bytecodes have been verified 6988 </constant> 6989 <constant id="JVMTI_CLASS_STATUS_PREPARED" num="2"> 6990 Class preparation is complete 6991 </constant> 6992 <constant id="JVMTI_CLASS_STATUS_INITIALIZED" num="4"> 6993 Class initialization is complete. Static initializer has been run. 6994 </constant> 6995 <constant id="JVMTI_CLASS_STATUS_ERROR" num="8"> 6996 Error during initialization makes class unusable 6997 </constant> 6998 <constant id="JVMTI_CLASS_STATUS_ARRAY" num="16"> 6999 Class is an array. If set, all other bits are zero. 7000 </constant> 7001 <constant id="JVMTI_CLASS_STATUS_PRIMITIVE" num="32"> 7002 Class is a primitive class (for example, <code>java.lang.Integer.TYPE</code>). 7003 If set, all other bits are zero. 7004 </constant> 7005 </constants> 7006 </description> 7007 <origin>jvmdi</origin> 7008 <capabilities> 7009 </capabilities> 7010 <parameters> 7011 <param id="klass"> 7012 <jclass/> 7013 <description> 7014 The class to query. 7015 </description> 7016 </param> 7017 <param id="status_ptr"> 7018 <outptr><jint/></outptr> 7019 <description> 7020 On return, points to the current state of this class as one or 7021 more of the <internallink id="jvmtiClassStatus">class status flags</internallink>. 7022 </description> 7023 </param> 7024 </parameters> 7025 <errors> 7026 </errors> 7027 </function> 7028 7029 <function id="GetSourceFileName" phase="start" num="50"> 7030 <synopsis>Get Source File Name</synopsis> 7031 <description> 7032 For the class indicated by <code>klass</code>, return the source file 7033 name via <code>source_name_ptr</code>. The returned string 7034 is a file name only and never contains a directory name. 7035 <p/> 7036 For primitive classes (for example, <code>java.lang.Integer.TYPE</code>) 7037 and for arrays this function returns 7038 <errorlink id="JVMTI_ERROR_ABSENT_INFORMATION"></errorlink>. 7039 </description> 7040 <origin>jvmdi</origin> 7041 <capabilities> 7042 <required id="can_get_source_file_name"></required> 7043 </capabilities> 7044 <parameters> 7045 <param id="klass"> 7046 <jclass/> 7047 <description> 7048 The class to query. 7049 </description> 7050 </param> 7051 <param id="source_name_ptr"> 7052 <allocbuf><char/></allocbuf> 7053 <description> 7054 On return, points to the class's source file name, encoded as a 7055 <internallink id="mUTF">modified UTF-8</internallink> string. 7056 </description> 7057 </param> 7058 </parameters> 7059 <errors> 7060 <error id="JVMTI_ERROR_ABSENT_INFORMATION"> 7061 Class information does not include a source file name. This includes 7062 cases where the class is an array class or primitive class. 7063 </error> 7064 </errors> 7065 </function> 7066 7067 <function id="GetClassModifiers" phase="start" num="51"> 7068 <synopsis>Get Class Modifiers</synopsis> 7069 <description> 7070 For the class indicated by <code>klass</code>, return the access 7071 flags 7072 via <code>modifiers_ptr</code>. 7073 Access flags are defined in <vmspec chapter="4"/>. 7074 <p/> 7075 If the class is an array class, then its public, private, and protected 7076 modifiers are the same as those of its component type. For arrays of 7077 primitives, this component type is represented by one of the primitive 7078 classes (for example, <code>java.lang.Integer.TYPE</code>). 7079 <p/> 7080 If the class is a primitive class, its public modifier is always true, 7081 and its protected and private modifiers are always false. 7082 <p/> 7083 If the class is an array class or a primitive class then its final 7084 modifier is always true and its interface modifier is always false. 7085 The values of its other modifiers are not determined by this specification. 7086 7087 </description> 7088 <origin>jvmdi</origin> 7089 <capabilities> 7090 </capabilities> 7091 <parameters> 7092 <param id="klass"> 7093 <jclass/> 7094 <description> 7095 The class to query. 7096 </description> 7097 </param> 7098 <param id="modifiers_ptr"> 7099 <outptr><jint/></outptr> 7100 <description> 7101 On return, points to the current access flags of this class. 7102 7103 </description> 7104 </param> 7105 </parameters> 7106 <errors> 7107 </errors> 7108 </function> 7109 7110 <function id="GetClassMethods" phase="start" num="52"> 7111 <synopsis>Get Class Methods</synopsis> 7112 <description> 7113 For the class indicated by <code>klass</code>, return a count of 7114 methods via <code>method_count_ptr</code> and a list of 7115 method IDs via <code>methods_ptr</code>. The method list contains 7116 constructors and static initializers as well as true methods. 7117 Only directly declared methods are returned (not inherited methods). 7118 An empty method list is returned for array classes and primitive classes 7119 (for example, <code>java.lang.Integer.TYPE</code>). 7120 </description> 7121 <origin>jvmdi</origin> 7122 <capabilities> 7123 <capability id="can_maintain_original_method_order"/> 7124 </capabilities> 7125 <parameters> 7126 <param id="klass"> 7127 <jclass/> 7128 <description> 7129 The class to query. 7130 </description> 7131 </param> 7132 <param id="method_count_ptr"> 7133 <outptr><jint/></outptr> 7134 <description> 7135 On return, points to the number of methods declared in this class. 7136 </description> 7137 </param> 7138 <param id="methods_ptr"> 7139 <allocbuf outcount="method_count_ptr"><jmethodID class="klass"/></allocbuf> 7140 <description> 7141 On return, points to the method ID array. 7142 </description> 7143 </param> 7144 </parameters> 7145 <errors> 7146 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED"> 7147 <paramlink id="klass"></paramlink> is not prepared. 7148 </error> 7149 </errors> 7150 </function> 7151 7152 <function id="GetClassFields" phase="start" num="53"> 7153 <synopsis>Get Class Fields</synopsis> 7154 <description> 7155 For the class indicated by <code>klass</code>, return a count of fields 7156 via <code>field_count_ptr</code> and a list of field IDs via 7157 <code>fields_ptr</code>. 7158 Only directly declared fields are returned (not inherited fields). 7159 Fields are returned in the order they occur in the class file. 7160 An empty field list is returned for array classes and primitive classes 7161 (for example, <code>java.lang.Integer.TYPE</code>). 7162 Use JNI to determine the length of an array. 7163 </description> 7164 <origin>jvmdi</origin> 7165 <capabilities> 7166 </capabilities> 7167 <parameters> 7168 <param id="klass"> 7169 <jclass/> 7170 <description> 7171 The class to query. 7172 </description> 7173 </param> 7174 <param id="field_count_ptr"> 7175 <outptr><jint/></outptr> 7176 <description> 7177 On return, points to the number of fields declared in this class. 7178 </description> 7179 </param> 7180 <param id="fields_ptr"> 7181 <allocbuf outcount="field_count_ptr"><jfieldID/></allocbuf> 7182 <description> 7183 On return, points to the field ID array. 7184 </description> 7185 </param> 7186 </parameters> 7187 <errors> 7188 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED"> 7189 <paramlink id="klass"></paramlink> is not prepared. 7190 </error> 7191 </errors> 7192 </function> 7193 7194 <function id="GetImplementedInterfaces" phase="start" num="54"> 7195 <synopsis>Get Implemented Interfaces</synopsis> 7196 <description> 7197 Return the direct super-interfaces of this class. For a class, this 7198 function returns the interfaces declared in its <code>implements</code> 7199 clause. For an interface, this function returns the interfaces declared in 7200 its <code>extends</code> clause. 7201 An empty interface list is returned for array classes and primitive classes 7202 (for example, <code>java.lang.Integer.TYPE</code>). 7203 </description> 7204 <origin>jvmdi</origin> 7205 <capabilities> 7206 </capabilities> 7207 <parameters> 7208 <param id="klass"> 7209 <jclass/> 7210 <description> 7211 The class to query. 7212 </description> 7213 </param> 7214 <param id="interface_count_ptr"> 7215 <outptr><jint/></outptr> 7216 <description> 7217 On return, points to the number of interfaces. 7218 </description> 7219 </param> 7220 <param id="interfaces_ptr"> 7221 <allocbuf outcount="interface_count_ptr"><jclass/></allocbuf> 7222 <description> 7223 On return, points to the interface array. 7224 </description> 7225 </param> 7226 </parameters> 7227 <errors> 7228 <error id="JVMTI_ERROR_CLASS_NOT_PREPARED"> 7229 <paramlink id="klass"></paramlink> is not prepared. 7230 </error> 7231 </errors> 7232 </function> 7233 7234 <function id="GetClassVersionNumbers" phase="start" num="145" since="1.1"> 7235 <synopsis>Get Class Version Numbers</synopsis> 7236 <description> 7237 For the class indicated by <code>klass</code>, 7238 return the minor and major version numbers, 7239 as defined in 7240 <vmspec chapter="4"/>. 7241 </description> 7242 <origin>new</origin> 7243 <capabilities> 7244 </capabilities> 7245 <parameters> 7246 <param id="klass"> 7247 <jclass/> 7248 <description> 7249 The class to query. 7250 </description> 7251 </param> 7252 <param id="minor_version_ptr"> 7253 <outptr><jint/></outptr> 7254 <description> 7255 On return, points to the value of the 7256 <code>minor_version</code> item of the 7257 Class File Format. 7258 Note: to be consistent with the Class File Format, 7259 the minor version number is the first parameter. 7260 </description> 7261 </param> 7262 <param id="major_version_ptr"> 7263 <outptr><jint/></outptr> 7264 <description> 7265 On return, points to the value of the 7266 <code>major_version</code> item of the 7267 Class File Format. 7268 </description> 7269 </param> 7270 </parameters> 7271 <errors> 7272 <error id="JVMTI_ERROR_ABSENT_INFORMATION"> 7273 The class is a primitive or array class. 7274 </error> 7275 </errors> 7276 </function> 7277 7278 <function id="GetConstantPool" phase="start" num="146" since="1.1"> 7279 <synopsis>Get Constant Pool</synopsis> 7280 <description> 7281 For the class indicated by <code>klass</code>, 7282 return the raw bytes of the constant pool in the format of the 7283 <code>constant_pool</code> item of 7284 <vmspec chapter="4"/>. 7285 The format of the constant pool may differ between versions 7286 of the Class File Format, so, the 7287 <functionlink id="GetClassVersionNumbers">minor and major 7288 class version numbers</functionlink> should be checked for 7289 compatibility. 7290 <p/> 7291 The returned constant pool might not have the same layout or 7292 contents as the constant pool in the defining class file. 7293 The constant pool returned by GetConstantPool() may have 7294 more or fewer entries than the defining constant pool. 7295 Entries may be in a different order. 7296 The constant pool returned by GetConstantPool() will match the 7297 constant pool used by 7298 <functionlink id="GetBytecodes">GetBytecodes()</functionlink>. 7299 That is, the bytecodes returned by GetBytecodes() will have 7300 constant pool indices which refer to constant pool entries returned 7301 by GetConstantPool(). 7302 Note that since <functionlink id="RetransformClasses"/> 7303 and <functionlink id="RedefineClasses"/> can change 7304 the constant pool, the constant pool returned by this function 7305 can change accordingly. Thus, the correspondence between 7306 GetConstantPool() and GetBytecodes() does not hold if there 7307 is an intervening class retransformation or redefinition. 7308 The value of a constant pool entry used by a given bytecode will 7309 match that of the defining class file (even if the indices don't match). 7310 Constant pool entries which are not used directly or indirectly by 7311 bytecodes (for example, UTF-8 strings associated with annotations) are 7312 not required to exist in the returned constant pool. 7313 </description> 7314 <origin>new</origin> 7315 <capabilities> 7316 <required id="can_get_constant_pool"></required> 7317 </capabilities> 7318 <parameters> 7319 <param id="klass"> 7320 <jclass/> 7321 <description> 7322 The class to query. 7323 </description> 7324 </param> 7325 <param id="constant_pool_count_ptr"> 7326 <outptr><jint/></outptr> 7327 <description> 7328 On return, points to the number of entries 7329 in the constant pool table plus one. 7330 This corresponds to the <code>constant_pool_count</code> 7331 item of the Class File Format. 7332 </description> 7333 </param> 7334 <param id="constant_pool_byte_count_ptr"> 7335 <outptr><jint/></outptr> 7336 <description> 7337 On return, points to the number of bytes 7338 in the returned raw constant pool. 7339 </description> 7340 </param> 7341 <param id="constant_pool_bytes_ptr"> 7342 <allocbuf outcount="constant_pool_byte_count_ptr"><uchar/></allocbuf> 7343 <description> 7344 On return, points to the raw constant pool, that is the bytes 7345 defined by the <code>constant_pool</code> item of the 7346 Class File Format 7347 </description> 7348 </param> 7349 </parameters> 7350 <errors> 7351 <error id="JVMTI_ERROR_ABSENT_INFORMATION"> 7352 The class is a primitive or array class. 7353 </error> 7354 </errors> 7355 </function> 7356 7357 <function id="IsInterface" phase="start" num="55"> 7358 <synopsis>Is Interface</synopsis> 7359 <description> 7360 Determines whether a class object reference represents an interface. 7361 The <code>jboolean</code> result is 7362 <code>JNI_TRUE</code> if the "class" is actually an interface, 7363 <code>JNI_FALSE</code> otherwise. 7364 </description> 7365 <origin>jvmdi</origin> 7366 <capabilities> 7367 </capabilities> 7368 <parameters> 7369 <param id="klass"> 7370 <jclass/> 7371 <description> 7372 The class to query. 7373 </description> 7374 </param> 7375 <param id="is_interface_ptr"> 7376 <outptr><jboolean/></outptr> 7377 <description> 7378 On return, points to the boolean result of this function. 7379 7380 </description> 7381 </param> 7382 </parameters> 7383 <errors> 7384 </errors> 7385 </function> 7386 7387 <function id="IsArrayClass" phase="start" num="56"> 7388 <synopsis>Is Array Class</synopsis> 7389 <description> 7390 Determines whether a class object reference represents an array. 7391 The <code>jboolean</code> result is 7392 <code>JNI_TRUE</code> if the class is an array, 7393 <code>JNI_FALSE</code> otherwise. 7394 </description> 7395 <origin>jvmdi</origin> 7396 <capabilities> 7397 </capabilities> 7398 <parameters> 7399 <param id="klass"> 7400 <jclass/> 7401 <description> 7402 The class to query. 7403 </description> 7404 </param> 7405 <param id="is_array_class_ptr"> 7406 <outptr><jboolean/></outptr> 7407 <description> 7408 On return, points to the boolean result of this function. 7409 7410 </description> 7411 </param> 7412 </parameters> 7413 <errors> 7414 </errors> 7415 </function> 7416 7417 <function id="IsModifiableClass" jkernel="yes" phase="start" num="45" since="1.1"> 7418 <synopsis>Is Modifiable Class</synopsis> 7419 <description> 7420 Determines whether a class is modifiable. 7421 If a class is modifiable (<paramlink id="is_modifiable_class_ptr"/> 7422 returns <code>JNI_TRUE</code>) the class can be 7423 redefined with <functionlink id="RedefineClasses"/> (assuming 7424 the agent possesses the 7425 <fieldlink id="can_redefine_classes" struct="jvmtiCapabilities"/> 7426 capability) or 7427 retransformed with <functionlink id="RetransformClasses"/> (assuming 7428 the agent possesses the 7429 <fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/> 7430 capability). 7431 If a class is not modifiable (<paramlink id="is_modifiable_class_ptr"/> 7432 returns <code>JNI_FALSE</code>) the class can be neither 7433 redefined nor retransformed. 7434 <p/> 7435 Primitive classes (for example, <code>java.lang.Integer.TYPE</code>), 7436 array classes, and some implementation defined classes are never modifiable. 7437 <p/> 7438 </description> 7439 <origin>new</origin> 7440 <capabilities> 7441 <capability id="can_redefine_any_class"> 7442 If possessed then all classes (except primitive, array, and some implementation defined 7443 classes) are modifiable (redefine or retransform). 7444 </capability> 7445 <capability id="can_retransform_any_class"> 7446 If possessed then all classes (except primitive, array, and some implementation defined 7447 classes) are modifiable with <functionlink id="RetransformClasses"/>. 7448 </capability> 7449 <capability id="can_redefine_classes"> 7450 No effect on the result of the function. 7451 But must additionally be possessed to modify the class with 7452 <functionlink id="RedefineClasses"/>. 7453 </capability> 7454 <capability id="can_retransform_classes"> 7455 No effect on the result of the function. 7456 But must additionally be possessed to modify the class with 7457 <functionlink id="RetransformClasses"/>. 7458 </capability> 7459 </capabilities> 7460 <parameters> 7461 <param id="klass"> 7462 <jclass/> 7463 <description> 7464 The class to query. 7465 </description> 7466 </param> 7467 <param id="is_modifiable_class_ptr"> 7468 <outptr><jboolean/></outptr> 7469 <description> 7470 On return, points to the boolean result of this function. 7471 </description> 7472 </param> 7473 </parameters> 7474 <errors> 7475 </errors> 7476 </function> 7477 7478 <function id="GetClassLoader" phase="start" num="57"> 7479 <synopsis>Get Class Loader</synopsis> 7480 <description> 7481 For the class indicated by <code>klass</code>, return via 7482 <code>classloader_ptr</code> a reference to the class loader for the 7483 class. 7484 </description> 7485 <origin>jvmdi</origin> 7486 <capabilities> 7487 </capabilities> 7488 <parameters> 7489 <param id="klass"> 7490 <jclass/> 7491 <description> 7492 The class to query. 7493 </description> 7494 </param> 7495 <param id="classloader_ptr"> 7496 <outptr><jobject/></outptr> 7497 <description> 7498 On return, points to the class loader that loaded 7499 this class. 7500 If the class was not created by a class loader 7501 or if the class loader is the bootstrap class loader, 7502 points to <code>NULL</code>. 7503 </description> 7504 </param> 7505 </parameters> 7506 <errors> 7507 </errors> 7508 7509 </function> 7510 7511 <function id="GetSourceDebugExtension" phase="start" num="90"> 7512 <synopsis>Get Source Debug Extension</synopsis> 7513 <description> 7514 For the class indicated by <code>klass</code>, return the debug 7515 extension via <code>source_debug_extension_ptr</code>. 7516 The returned string 7517 contains exactly the debug extension information present in the 7518 class file of <code>klass</code>. 7519 </description> 7520 <origin>jvmdi</origin> 7521 <capabilities> 7522 <required id="can_get_source_debug_extension"></required> 7523 </capabilities> 7524 <parameters> 7525 <param id="klass"> 7526 <jclass/> 7527 <description> 7528 The class to query. 7529 </description> 7530 </param> 7531 <param id="source_debug_extension_ptr"> 7532 <allocbuf><char/></allocbuf> 7533 <description> 7534 On return, points to the class's debug extension, encoded as a 7535 <internallink id="mUTF">modified UTF-8</internallink> string. 7536 </description> 7537 </param> 7538 </parameters> 7539 <errors> 7540 <error id="JVMTI_ERROR_ABSENT_INFORMATION"> 7541 Class information does not include a debug extension. 7542 </error> 7543 </errors> 7544 </function> 7545 7546 <function id="RetransformClasses" jkernel="yes" num="152" since="1.1"> 7547 <synopsis>Retransform Classes</synopsis> 7548 <description> 7549 This function facilitates the 7550 <internallink id="bci">bytecode instrumentation</internallink> 7551 of already loaded classes. 7552 To replace the class definition without reference to the existing 7553 bytecodes, as one might do when recompiling from source for 7554 fix-and-continue debugging, <functionlink id="RedefineClasses"/> 7555 function should be used instead. 7556 <p/> 7557 When classes are initially loaded or when they are 7558 <functionlink id="RedefineClasses">redefined</functionlink>, 7559 the initial class file bytes can be transformed with the 7560 <eventlink id="ClassFileLoadHook"/> event. 7561 This function reruns the transformation process 7562 (whether or not a transformation has previously occurred). 7563 This retransformation follows these steps: 7564 <ul> 7565 <li>starting from the initial class file bytes 7566 </li> 7567 <li>for each <fieldlink id="can_retransform_classes" 7568 struct="jvmtiCapabilities">retransformation 7569 incapable</fieldlink> 7570 agent which received a 7571 <code>ClassFileLoadHook</code> event during the previous 7572 load or redefine, the bytes it returned 7573 (via the <code>new_class_data</code> parameter) 7574 are reused as the output of the transformation; 7575 note that this is equivalent to reapplying 7576 the previous transformation, unaltered. except that 7577 the <code>ClassFileLoadHook</code> event 7578 is <b>not</b> sent to these agents 7579 </li> 7580 <li>for each <fieldlink id="can_retransform_classes" 7581 struct="jvmtiCapabilities">retransformation 7582 capable</fieldlink> 7583 agent, the <code>ClassFileLoadHook</code> event is sent, 7584 allowing a new transformation to be applied 7585 </li> 7586 <li>the transformed class file bytes are installed as the new 7587 definition of the class 7588 </li> 7589 </ul> 7590 See the <eventlink id="ClassFileLoadHook"/> event for more details. 7591 <p/> 7592 The initial class file bytes represent the bytes passed to 7593 <code>ClassLoader.defineClass</code> 7594 or <code>RedefineClasses</code> (before any transformations 7595 were applied), however they may not exactly match them. 7596 The constant pool may differ in ways described in 7597 <functionlink id="GetConstantPool"/>. 7598 Constant pool indices in the bytecodes of methods will correspond. 7599 Some attributes may not be present. 7600 Where order is not meaningful, for example the order of methods, 7601 order may not be preserved. 7602 <p/> 7603 Retransformation can cause new versions of methods to be installed. 7604 Old method versions may become 7605 <internallink id="obsoleteMethods">obsolete</internallink> 7606 The new method version will be used on new invokes. 7607 If a method has active stack frames, those active frames continue to 7608 run the bytecodes of the original method version. 7609 <p/> 7610 This function does not cause any initialization except that which 7611 would occur under the customary JVM semantics. 7612 In other words, retransforming a class does not cause its initializers to be 7613 run. The values of static fields will remain as they were 7614 prior to the call. 7615 <p/> 7616 Threads need not be suspended. 7617 <p/> 7618 All breakpoints in the class are cleared. 7619 <p/> 7620 All attributes are updated. 7621 <p/> 7622 Instances of the retransformed class are not affected -- fields retain their 7623 previous values. 7624 <functionlink id="GetTag">Tags</functionlink> on the instances are 7625 also unaffected. 7626 <p/> 7627 In response to this call, no events other than the 7628 <eventlink id="ClassFileLoadHook"/> event 7629 will be sent. 7630 <p/> 7631 The retransformation may change method bodies, the constant pool and attributes. 7632 The retransformation must not add, remove or rename fields or methods, change the 7633 signatures of methods, change modifiers, or change inheritance. 7634 These restrictions may be lifted in future versions. 7635 See the error return description below for information on error codes 7636 returned if an unsupported retransformation is attempted. 7637 The class file bytes are not verified or installed until they have passed 7638 through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the 7639 returned error code reflects the result of the transformations. 7640 If any error code is returned other than <code>JVMTI_ERROR_NONE</code>, 7641 none of the classes to be retransformed will have a new definition installed. 7642 When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>) 7643 all of the classes to be retransformed will have their new definitions installed. 7644 </description> 7645 <origin>new</origin> 7646 <capabilities> 7647 <required id="can_retransform_classes"></required> 7648 <capability id="can_retransform_any_class"></capability> 7649 </capabilities> 7650 <parameters> 7651 <param id="class_count"> 7652 <jint min="0"/> 7653 <description> 7654 The number of classes to be retransformed. 7655 </description> 7656 </param> 7657 <param id="classes"> 7658 <inbuf incount="class_count"><jclass/></inbuf> 7659 <description> 7660 The array of classes to be retransformed. 7661 </description> 7662 </param> 7663 </parameters> 7664 <errors> 7665 <error id="JVMTI_ERROR_UNMODIFIABLE_CLASS"> 7666 One of the <paramlink id="classes"/> cannot be modified. 7667 See <functionlink id="IsModifiableClass"/>. 7668 </error> 7669 <error id="JVMTI_ERROR_INVALID_CLASS"> 7670 One of the <paramlink id="classes"/> is not a valid class. 7671 </error> 7672 <error id="JVMTI_ERROR_UNSUPPORTED_VERSION"> 7673 A retransformed class file has a version number not supported by this VM. 7674 </error> 7675 <error id="JVMTI_ERROR_INVALID_CLASS_FORMAT"> 7676 A retransformed class file is malformed (The VM would return a <code>ClassFormatError</code>). 7677 </error> 7678 <error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION"> 7679 The retransformed class file definitions would lead to a circular definition 7680 (the VM would return a <code>ClassCircularityError</code>). 7681 </error> 7682 <error id="JVMTI_ERROR_FAILS_VERIFICATION"> 7683 The retransformed class file bytes fail verification. 7684 </error> 7685 <error id="JVMTI_ERROR_NAMES_DONT_MATCH"> 7686 The class name defined in a retransformed class file is 7687 different from the name in the old class object. 7688 </error> 7689 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED"> 7690 A retransformed class file would require adding a method. 7691 </error> 7692 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED"> 7693 A retransformed class file changes a field. 7694 </error> 7695 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED"> 7696 A direct superclass is different for a retransformed class file, 7697 or the set of directly implemented 7698 interfaces is different. 7699 </error> 7700 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED"> 7701 A retransformed class file does not declare a method 7702 declared in the old class version. 7703 </error> 7704 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED"> 7705 A retransformed class file has different class modifiers. 7706 </error> 7707 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED"> 7708 A method in the retransformed class file has different modifiers 7709 than its counterpart in the old class version. 7710 </error> 7711 </errors> 7712 </function> 7713 7714 <function id="RedefineClasses" jkernel="yes" num="87"> 7715 <synopsis>Redefine Classes</synopsis> 7716 <typedef id="jvmtiClassDefinition" label="Class redefinition description"> 7717 <field id="klass"> 7718 <jclass/> 7719 <description> 7720 Class object for this class 7721 </description> 7722 </field> 7723 <field id="class_byte_count"> 7724 <jint/> 7725 <description> 7726 Number of bytes defining class (below) 7727 </description> 7728 </field> 7729 <field id="class_bytes"> 7730 <inbuf incount="class_byte_count"><uchar/></inbuf> 7731 <description> 7732 Bytes defining class (in <vmspec chapter="4"/>) 7733 </description> 7734 </field> 7735 </typedef> 7736 <description> 7737 All classes given are redefined according to the definitions 7738 supplied. 7739 This function is used to replace the definition of a class 7740 with a new definition, as might be needed in fix-and-continue 7741 debugging. 7742 Where the existing class file bytes are to be transformed, for 7743 example in 7744 <internallink id="bci">bytecode instrumentation</internallink>, 7745 <functionlink id="RetransformClasses"/> should be used. 7746 <p/> 7747 Redefinition can cause new versions of methods to be installed. 7748 Old method versions may become 7749 <internallink id="obsoleteMethods">obsolete</internallink> 7750 The new method version will be used on new invokes. 7751 If a method has active stack frames, those active frames continue to 7752 run the bytecodes of the original method version. 7753 If resetting of stack frames is desired, use 7754 <functionlink id="PopFrame"></functionlink> 7755 to pop frames with obsolete method versions. 7756 <p/> 7757 This function does not cause any initialization except that which 7758 would occur under the customary JVM semantics. 7759 In other words, redefining a class does not cause its initializers to be 7760 run. The values of static fields will remain as they were 7761 prior to the call. 7762 <p/> 7763 Threads need not be suspended. 7764 <p/> 7765 All breakpoints in the class are cleared. 7766 <p/> 7767 All attributes are updated. 7768 <p/> 7769 Instances of the redefined class are not affected -- fields retain their 7770 previous values. 7771 <functionlink id="GetTag">Tags</functionlink> on the instances are 7772 also unaffected. 7773 <p/> 7774 In response to this call, the <jvmti/> event 7775 <eventlink id="ClassFileLoadHook">Class File Load Hook</eventlink> 7776 will be sent (if enabled), but no other <jvmti/> events will be sent. 7777 <p/> 7778 The redefinition may change method bodies, the constant pool and attributes. 7779 The redefinition must not add, remove or rename fields or methods, change the 7780 signatures of methods, change modifiers, or change inheritance. 7781 These restrictions may be lifted in future versions. 7782 See the error return description below for information on error codes 7783 returned if an unsupported redefinition is attempted. 7784 The class file bytes are not verified or installed until they have passed 7785 through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the 7786 returned error code reflects the result of the transformations applied 7787 to the bytes passed into <paramlink id="class_definitions"/>. 7788 If any error code is returned other than <code>JVMTI_ERROR_NONE</code>, 7789 none of the classes to be redefined will have a new definition installed. 7790 When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>) 7791 all of the classes to be redefined will have their new definitions installed. 7792 </description> 7793 <origin>jvmdi</origin> 7794 <capabilities> 7795 <required id="can_redefine_classes"></required> 7796 <capability id="can_redefine_any_class"></capability> 7797 </capabilities> 7798 <parameters> 7799 <param id="class_count"> 7800 <jint min="0"/> 7801 <description> 7802 The number of classes specified in <code>class_definitions</code> 7803 </description> 7804 </param> 7805 <param id="class_definitions"> 7806 <inbuf incount="class_count"><struct>jvmtiClassDefinition</struct></inbuf> 7807 <description> 7808 The array of new class definitions 7809 </description> 7810 </param> 7811 </parameters> 7812 <errors> 7813 <error id="JVMTI_ERROR_NULL_POINTER"> 7814 One of <code>class_bytes</code> is <code>NULL</code>. 7815 </error> 7816 <error id="JVMTI_ERROR_UNMODIFIABLE_CLASS"> 7817 An element of <code>class_definitions</code> cannot be modified. 7818 See <functionlink id="IsModifiableClass"/>. 7819 </error> 7820 <error id="JVMTI_ERROR_INVALID_CLASS"> 7821 An element of <code>class_definitions</code> is not a valid class. 7822 </error> 7823 <error id="JVMTI_ERROR_UNSUPPORTED_VERSION"> 7824 A new class file has a version number not supported by this VM. 7825 </error> 7826 <error id="JVMTI_ERROR_INVALID_CLASS_FORMAT"> 7827 A new class file is malformed (The VM would return a <code>ClassFormatError</code>). 7828 </error> 7829 <error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION"> 7830 The new class file definitions would lead to a circular definition 7831 (the VM would return a <code>ClassCircularityError</code>). 7832 </error> 7833 <error id="JVMTI_ERROR_FAILS_VERIFICATION"> 7834 The class bytes fail verification. 7835 </error> 7836 <error id="JVMTI_ERROR_NAMES_DONT_MATCH"> 7837 The class name defined in a new class file is 7838 different from the name in the old class object. 7839 </error> 7840 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED"> 7841 A new class file would require adding a method. 7842 </error> 7843 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED"> 7844 A new class version changes a field. 7845 </error> 7846 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED"> 7847 A direct superclass is different for a new class 7848 version, or the set of directly implemented 7849 interfaces is different. 7850 </error> 7851 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED"> 7852 A new class version does not declare a method 7853 declared in the old class version. 7854 </error> 7855 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED"> 7856 A new class version has different modifiers. 7857 </error> 7858 <error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED"> 7859 A method in the new class version has different modifiers 7860 than its counterpart in the old class version. 7861 </error> 7862 <error id="JVMTI_ERROR_UNMODIFIABLE_MODULE"> 7863 A module cannot be modified. 7864 See <functionlink id="IsModifiableModule"/>. 7865 </error> 7866 </errors> 7867 </function> 7868 7869 </category> 7870 7871 <category id="object" label="Object"> 7872 7873 <function id="GetObjectSize" jkernel="yes" phase="start" num="154"> 7874 <synopsis>Get Object Size</synopsis> 7875 <description> 7876 For the object indicated by <code>object</code>, 7877 return via <code>size_ptr</code> the size of the object. 7878 This size is an implementation-specific approximation of 7879 the amount of storage consumed by this object. 7880 It may include some or all of the object's overhead, and thus 7881 is useful for comparison within an implementation but not 7882 between implementations. 7883 The estimate may change during a single invocation of the JVM. 7884 </description> 7885 <origin>new</origin> 7886 <capabilities> 7887 </capabilities> 7888 <parameters> 7889 <param id="object"> 7890 <jobject/> 7891 <description> 7892 The object to query. 7893 </description> 7894 </param> 7895 <param id="size_ptr"> 7896 <outptr><jlong/></outptr> 7897 <description> 7898 On return, points to the object's size in bytes. 7899 </description> 7900 </param> 7901 </parameters> 7902 <errors> 7903 </errors> 7904 </function> 7905 7906 <function id="GetObjectHashCode" phase="start" num="58"> 7907 <synopsis>Get Object Hash Code</synopsis> 7908 <description> 7909 For the object indicated by <code>object</code>, 7910 return via <code>hash_code_ptr</code> a hash code. 7911 This hash code could be used to maintain a hash table of object references, 7912 however, on some implementations this can cause significant performance 7913 impacts--in most cases 7914 <internallink id="Heap">tags</internallink> 7915 will be a more efficient means of associating information with objects. 7916 This function guarantees 7917 the same hash code value for a particular object throughout its life 7918 </description> 7919 <origin>jvmdi</origin> 7920 <capabilities> 7921 </capabilities> 7922 <parameters> 7923 <param id="object"> 7924 <jobject/> 7925 <description> 7926 The object to query. 7927 </description> 7928 </param> 7929 <param id="hash_code_ptr"> 7930 <outptr><jint/></outptr> 7931 <description> 7932 On return, points to the object's hash code. 7933 </description> 7934 </param> 7935 </parameters> 7936 <errors> 7937 </errors> 7938 </function> 7939 7940 <function id="GetObjectMonitorUsage" num="59"> 7941 <synopsis>Get Object Monitor Usage</synopsis> 7942 <typedef id="jvmtiMonitorUsage" label="Object monitor usage information"> 7943 <field id="owner"> 7944 <jthread/> 7945 <description> 7946 The thread owning this monitor, or <code>NULL</code> if unused 7947 </description> 7948 </field> 7949 <field id="entry_count"> 7950 <jint/> 7951 <description> 7952 The number of times the owning thread has entered the monitor 7953 </description> 7954 </field> 7955 <field id="waiter_count"> 7956 <jint/> 7957 <description> 7958 The number of threads waiting to own this monitor 7959 </description> 7960 </field> 7961 <field id="waiters"> 7962 <allocfieldbuf><jthread/></allocfieldbuf> 7963 <description> 7964 The <code>waiter_count</code> waiting threads 7965 </description> 7966 </field> 7967 <field id="notify_waiter_count"> 7968 <jint/> 7969 <description> 7970 The number of threads waiting to be notified by this monitor 7971 </description> 7972 </field> 7973 <field id="notify_waiters"> 7974 <allocfieldbuf><jthread/></allocfieldbuf> 7975 <description> 7976 The <code>notify_waiter_count</code> threads waiting to be notified 7977 </description> 7978 </field> 7979 </typedef> 7980 <description> 7981 Get information about the object's monitor. 7982 The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure 7983 are filled in with information about usage of the monitor. 7984 <todo> 7985 Decide and then clarify suspend requirements. 7986 </todo> 7987 </description> 7988 <origin>jvmdi</origin> 7989 <capabilities> 7990 <required id="can_get_monitor_info"></required> 7991 </capabilities> 7992 <parameters> 7993 <param id="object"> 7994 <jobject/> 7995 <description> 7996 The object to query. 7997 </description> 7998 </param> 7999 <param id="info_ptr"> 8000 <outptr><struct>jvmtiMonitorUsage</struct></outptr> 8001 <description> 8002 On return, filled with monitor information for the 8003 specified object. 8004 </description> 8005 </param> 8006 </parameters> 8007 <errors> 8008 </errors> 8009 </function> 8010 8011 <elide> 8012 <function id="GetObjectMonitors" num="116"> 8013 <synopsis>Get Object Monitors</synopsis> 8014 <description> 8015 Return the list of object monitors. 8016 <p/> 8017 Note: details about each monitor can be examined with 8018 <functionlink id="GetObjectMonitorUsage"></functionlink>. 8019 </description> 8020 <origin>new</origin> 8021 <capabilities> 8022 <required id="can_get_monitor_info"></required> 8023 </capabilities> 8024 <parameters> 8025 <param id="monitorCnt"> 8026 <outptr><jint/></outptr> 8027 <description> 8028 On return, pointer to the number 8029 of monitors returned in <code>monitors_ptr</code>. 8030 </description> 8031 </param> 8032 <param id="monitors_ptr"> 8033 <allocbuf outcount="monitorCnt"><jobject/></allocbuf> 8034 <description> 8035 On return, pointer to the monitor list. 8036 </description> 8037 </param> 8038 </parameters> 8039 <errors> 8040 </errors> 8041 </function> 8042 </elide> 8043 8044 </category> 8045 8046 <category id="fieldCategory" label="Field"> 8047 8048 <intro> 8049 </intro> 8050 8051 <function id="GetFieldName" phase="start" num="60"> 8052 <synopsis>Get Field Name (and Signature)</synopsis> 8053 <description> 8054 For the field indicated by <paramlink id="klass"/> and <paramlink id="field"/>, 8055 return the field name via <paramlink id="name_ptr"/> and field signature via 8056 <paramlink id="signature_ptr"/>. 8057 <p/> 8058 Field signatures are defined in the 8059 <externallink id="jni/index.html">JNI Specification</externallink> 8060 and are referred to as <code>field descriptors</code> in 8061 <vmspec chapter="4.3.2"/>. 8062 </description> 8063 <origin>jvmdiClone</origin> 8064 <capabilities> 8065 </capabilities> 8066 <parameters> 8067 <param id="klass"> 8068 <jclass field="field"/> 8069 <description> 8070 The class of the field to query. 8071 </description> 8072 </param> 8073 <param id="field"> 8074 <jfieldID class="klass"/> 8075 <description> 8076 The field to query. 8077 </description> 8078 </param> 8079 <param id="name_ptr"> 8080 <allocbuf> 8081 <char/> 8082 <nullok>the name is not returned</nullok> 8083 </allocbuf> 8084 <description> 8085 On return, points to the field name, encoded as a 8086 <internallink id="mUTF">modified UTF-8</internallink> string. 8087 </description> 8088 </param> 8089 <param id="signature_ptr"> 8090 <allocbuf> 8091 <char/> 8092 <nullok>the signature is not returned</nullok> 8093 </allocbuf> 8094 <description> 8095 On return, points to the field signature, encoded as a 8096 <internallink id="mUTF">modified UTF-8</internallink> string. 8097 </description> 8098 </param> 8099 <param id="generic_ptr"> 8100 <allocbuf> 8101 <char/> 8102 <nullok>the generic signature is not returned</nullok> 8103 </allocbuf> 8104 <description> 8105 On return, points to the generic signature of the field, encoded as a 8106 <internallink id="mUTF">modified UTF-8</internallink> string. 8107 If there is no generic signature attribute for the field, then, 8108 on return, points to <code>NULL</code>. 8109 </description> 8110 </param> 8111 </parameters> 8112 <errors> 8113 </errors> 8114 </function> 8115 8116 <function id="GetFieldDeclaringClass" phase="start" num="61"> 8117 <synopsis>Get Field Declaring Class</synopsis> 8118 <description> 8119 For the field indicated by <code>klass</code> and <code>field</code> 8120 return the class that defined it via <code>declaring_class_ptr</code>. 8121 The declaring class will either be <code>klass</code>, a superclass, or 8122 an implemented interface. 8123 </description> 8124 <origin>jvmdi</origin> 8125 <capabilities> 8126 </capabilities> 8127 <parameters> 8128 <param id="klass"> 8129 <jclass field="field"/> 8130 <description> 8131 The class to query. 8132 </description> 8133 </param> 8134 <param id="field"> 8135 <jfieldID class="klass"/> 8136 <description> 8137 The field to query. 8138 </description> 8139 </param> 8140 <param id="declaring_class_ptr"> 8141 <outptr><jclass/></outptr> 8142 <description> 8143 On return, points to the declaring class 8144 </description> 8145 </param> 8146 </parameters> 8147 <errors> 8148 </errors> 8149 </function> 8150 8151 <function id="GetFieldModifiers" phase="start" num="62"> 8152 <synopsis>Get Field Modifiers</synopsis> 8153 <description> 8154 For the field indicated by <code>klass</code> and <code>field</code> 8155 return the access flags via <code>modifiers_ptr</code>. 8156 Access flags are defined in <vmspec chapter="4"/>. 8157 </description> 8158 <origin>jvmdi</origin> 8159 <capabilities> 8160 </capabilities> 8161 <parameters> 8162 <param id="klass"> 8163 <jclass field="field"/> 8164 <description> 8165 The class to query. 8166 </description> 8167 </param> 8168 <param id="field"> 8169 <jfieldID class="klass"/> 8170 <description> 8171 The field to query. 8172 </description> 8173 </param> 8174 <param id="modifiers_ptr"> 8175 <outptr><jint/></outptr> 8176 <description> 8177 On return, points to the access flags. 8178 </description> 8179 </param> 8180 </parameters> 8181 <errors> 8182 </errors> 8183 </function> 8184 8185 <function id="IsFieldSynthetic" phase="start" num="63"> 8186 <synopsis>Is Field Synthetic</synopsis> 8187 <description> 8188 For the field indicated by <code>klass</code> and <code>field</code>, return a 8189 value indicating whether the field is synthetic via <code>is_synthetic_ptr</code>. 8190 Synthetic fields are generated by the compiler but not present in the 8191 original source code. 8192 </description> 8193 <origin>jvmdi</origin> 8194 <capabilities> 8195 <required id="can_get_synthetic_attribute"></required> 8196 </capabilities> 8197 <parameters> 8198 <param id="klass"> 8199 <jclass field="field"/> 8200 <description> 8201 The class of the field to query. 8202 </description> 8203 </param> 8204 <param id="field"> 8205 <jfieldID class="klass"/> 8206 <description> 8207 The field to query. 8208 </description> 8209 </param> 8210 <param id="is_synthetic_ptr"> 8211 <outptr><jboolean/></outptr> 8212 <description> 8213 On return, points to the boolean result of this function. 8214 </description> 8215 </param> 8216 </parameters> 8217 <errors> 8218 </errors> 8219 </function> 8220 8221 </category> 8222 8223 <category id="method" label="Method"> 8224 8225 <intro> 8226 These functions provide information about a method (represented as a 8227 <typelink id="jmethodID"/>) and set how methods are processed. 8228 </intro> 8229 8230 <intro id="obsoleteMethods" label="Obsolete Methods"> 8231 The functions <functionlink id="RetransformClasses"/> and 8232 <functionlink id="RedefineClasses"/> can cause new versions 8233 of methods to be installed. 8234 An original version of a method is considered equivalent 8235 to the new version if: 8236 <ul> 8237 <li>their bytecodes are the same except for indices into the 8238 constant pool and </li> 8239 <li>the referenced constants are equal.</li> 8240 </ul> 8241 An original method version which is not equivalent to the 8242 new method version is called obsolete and is assigned a new method ID; 8243 the original method ID now refers to the new method version. 8244 A method ID can be tested for obsolescence with 8245 <functionlink id="IsMethodObsolete"/>. 8246 </intro> 8247 8248 <function id="GetMethodName" phase="start" num="64"> 8249 <synopsis>Get Method Name (and Signature)</synopsis> 8250 <description> 8251 For the method indicated by <code>method</code>, 8252 return the method name via <code>name_ptr</code> and method signature via 8253 <code>signature_ptr</code>. 8254 <p/> 8255 Method signatures are defined in the 8256 <externallink id="jni/index.html">JNI Specification</externallink> 8257 and are referred to as <code>method descriptors</code> in 8258 <vmspec chapter="4.3.3"/>. 8259 Note this is different 8260 than method signatures as defined in the <i>Java Language Specification</i>. 8261 </description> 8262 <origin>jvmdiClone</origin> 8263 <capabilities> 8264 </capabilities> 8265 <parameters> 8266 <param id="method"> 8267 <jmethodID/> 8268 <description> 8269 The method to query. 8270 </description> 8271 </param> 8272 <param id="name_ptr"> 8273 <allocbuf> 8274 <char/> 8275 <nullok>the name is not returned</nullok> 8276 </allocbuf> 8277 <description> 8278 On return, points to the method name, encoded as a 8279 <internallink id="mUTF">modified UTF-8</internallink> string. 8280 </description> 8281 </param> 8282 <param id="signature_ptr"> 8283 <allocbuf> 8284 <char/> 8285 <nullok>the signature is not returned</nullok> 8286 </allocbuf> 8287 <description> 8288 On return, points to the method signature, encoded as a 8289 <internallink id="mUTF">modified UTF-8</internallink> string. 8290 </description> 8291 </param> 8292 <param id="generic_ptr"> 8293 <allocbuf> 8294 <char/> 8295 <nullok>the generic signature is not returned</nullok> 8296 </allocbuf> 8297 <description> 8298 On return, points to the generic signature of the method, encoded as a 8299 <internallink id="mUTF">modified UTF-8</internallink> string. 8300 If there is no generic signature attribute for the method, then, 8301 on return, points to <code>NULL</code>. 8302 </description> 8303 </param> 8304 </parameters> 8305 <errors> 8306 </errors> 8307 </function> 8308 8309 <function id="GetMethodDeclaringClass" phase="start" num="65"> 8310 <synopsis>Get Method Declaring Class</synopsis> 8311 <description> 8312 For the method indicated by <code>method</code>, 8313 return the class that defined it via <code>declaring_class_ptr</code>. 8314 </description> 8315 <origin>jvmdi</origin> 8316 <capabilities> 8317 </capabilities> 8318 <parameters> 8319 <param id="klass"> 8320 <jclass method="method"/> 8321 <description> 8322 The class to query. 8323 </description> 8324 </param> 8325 <param id="method"> 8326 <jmethodID class="klass"/> 8327 <description> 8328 The method to query. 8329 </description> 8330 </param> 8331 <param id="declaring_class_ptr"> 8332 <outptr><jclass/></outptr> 8333 <description> 8334 On return, points to the declaring class 8335 </description> 8336 </param> 8337 </parameters> 8338 <errors> 8339 </errors> 8340 </function> 8341 8342 <function id="GetMethodModifiers" phase="start" num="66"> 8343 <synopsis>Get Method Modifiers</synopsis> 8344 <description> 8345 For the method indicated by <code>method</code>, 8346 return the access flags via <code>modifiers_ptr</code>. 8347 Access flags are defined in <vmspec chapter="4"/>. 8348 </description> 8349 <origin>jvmdi</origin> 8350 <capabilities> 8351 </capabilities> 8352 <parameters> 8353 <param id="klass"> 8354 <jclass method="method"/> 8355 <description> 8356 The class to query. 8357 </description> 8358 </param> 8359 <param id="method"> 8360 <jmethodID class="klass"/> 8361 <description> 8362 The method to query. 8363 </description> 8364 </param> 8365 <param id="modifiers_ptr"> 8366 <outptr><jint/></outptr> 8367 <description> 8368 On return, points to the access flags. 8369 </description> 8370 </param> 8371 </parameters> 8372 <errors> 8373 </errors> 8374 </function> 8375 8376 <function id="GetMaxLocals" phase="start" num="68"> 8377 <synopsis>Get Max Locals</synopsis> 8378 <description> 8379 For the method indicated by <code>method</code>, 8380 return the number of local variable slots used by the method, 8381 including the local variables used to pass parameters to the 8382 method on its invocation. 8383 <p/> 8384 See <code>max_locals</code> in <vmspec chapter="4.7.3"/>. 8385 </description> 8386 <origin>jvmdi</origin> 8387 <capabilities> 8388 </capabilities> 8389 <parameters> 8390 <param id="klass"> 8391 <jclass method="method"/> 8392 <description> 8393 The class to query. 8394 </description> 8395 </param> 8396 <param id="method"> 8397 <jmethodID class="klass" native="error"/> 8398 <description> 8399 The method to query. 8400 </description> 8401 </param> 8402 <param id="max_ptr"> 8403 <outptr><jint/></outptr> 8404 <description> 8405 On return, points to the maximum number of local slots 8406 </description> 8407 </param> 8408 </parameters> 8409 <errors> 8410 </errors> 8411 </function> 8412 8413 <function id="GetArgumentsSize" phase="start" num="69"> 8414 <synopsis>Get Arguments Size</synopsis> 8415 <description> 8416 For the method indicated by <code>method</code>, 8417 return via <code>max_ptr</code> the number of local variable slots used 8418 by the method's arguments. 8419 Note that two-word arguments use two slots. 8420 </description> 8421 <origin>jvmdi</origin> 8422 <capabilities> 8423 </capabilities> 8424 <parameters> 8425 <param id="klass"> 8426 <jclass method="method"/> 8427 <description> 8428 The class to query. 8429 </description> 8430 </param> 8431 <param id="method"> 8432 <jmethodID class="klass" native="error"/> 8433 <description> 8434 The method to query. 8435 </description> 8436 </param> 8437 <param id="size_ptr"> 8438 <outptr><jint/></outptr> 8439 <description> 8440 On return, points to the number of argument slots 8441 </description> 8442 </param> 8443 </parameters> 8444 <errors> 8445 </errors> 8446 </function> 8447 8448 <function id="GetLineNumberTable" phase="start" num="70"> 8449 <synopsis>Get Line Number Table</synopsis> 8450 <typedef id="jvmtiLineNumberEntry" label="Line number table entry"> 8451 <field id="start_location"> 8452 <jlocation/> 8453 <description> 8454 the <datalink id="jlocation"></datalink> where the line begins 8455 </description> 8456 </field> 8457 <field id="line_number"> 8458 <jint/> 8459 <description> 8460 the line number 8461 </description> 8462 </field> 8463 </typedef> 8464 <description> 8465 For the method indicated by <code>method</code>, 8466 return a table of source line number entries. The size of the table is 8467 returned via <code>entry_count_ptr</code> and the table itself is 8468 returned via <code>table_ptr</code>. 8469 </description> 8470 <origin>jvmdi</origin> 8471 <capabilities> 8472 <required id="can_get_line_numbers"></required> 8473 </capabilities> 8474 <parameters> 8475 <param id="klass"> 8476 <jclass method="method"/> 8477 <description> 8478 The class to query. 8479 </description> 8480 </param> 8481 <param id="method"> 8482 <jmethodID class="klass" native="error"/> 8483 <description> 8484 The method to query. 8485 </description> 8486 </param> 8487 <param id="entry_count_ptr"> 8488 <outptr><jint/></outptr> 8489 <description> 8490 On return, points to the number of entries in the table 8491 </description> 8492 </param> 8493 <param id="table_ptr"> 8494 <allocbuf outcount="entry_count_ptr"><struct>jvmtiLineNumberEntry</struct></allocbuf> 8495 <description> 8496 On return, points to the line number table pointer. 8497 </description> 8498 </param> 8499 </parameters> 8500 <errors> 8501 <error id="JVMTI_ERROR_ABSENT_INFORMATION"> 8502 Class information does not include line numbers. 8503 </error> 8504 </errors> 8505 </function> 8506 8507 <function id="GetMethodLocation" phase="start" num="71"> 8508 <synopsis>Get Method Location</synopsis> 8509 <description> 8510 For the method indicated by <code>method</code>, 8511 return the beginning and ending addresses through 8512 <code>start_location_ptr</code> and <code>end_location_ptr</code>. In a 8513 conventional byte code indexing scheme, 8514 <code>start_location_ptr</code> will always point to zero 8515 and <code>end_location_ptr</code> 8516 will always point to the byte code count minus one. 8517 </description> 8518 <origin>jvmdi</origin> 8519 <capabilities> 8520 </capabilities> 8521 <parameters> 8522 <param id="klass"> 8523 <jclass method="method"/> 8524 <description> 8525 The class to query. 8526 </description> 8527 </param> 8528 <param id="method"> 8529 <jmethodID class="klass" native="error"/> 8530 <description> 8531 The method to query. 8532 </description> 8533 </param> 8534 <param id="start_location_ptr"> 8535 <outptr><jlocation/></outptr> 8536 <description> 8537 On return, points to the first location, or 8538 <code>-1</code> if location information is not available. 8539 If the information is available and 8540 <functionlink id="GetJLocationFormat"></functionlink> 8541 returns <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink> 8542 then this will always be zero. 8543 </description> 8544 </param> 8545 <param id="end_location_ptr"> 8546 <outptr><jlocation/></outptr> 8547 <description> 8548 On return, points to the last location, 8549 or <code>-1</code> if location information is not available. 8550 </description> 8551 </param> 8552 </parameters> 8553 <errors> 8554 <error id="JVMTI_ERROR_ABSENT_INFORMATION"> 8555 Class information does not include method sizes. 8556 </error> 8557 </errors> 8558 </function> 8559 8560 <function id="GetLocalVariableTable" num="72"> 8561 <synopsis>Get Local Variable Table</synopsis> 8562 <typedef id="jvmtiLocalVariableEntry" label="Local variable table entry"> 8563 <field id="start_location"> 8564 <jlocation/> 8565 <description> 8566 The code array index where the local variable is first valid 8567 (that is, where it must have a value). 8568 </description> 8569 </field> 8570 <field id="length"> 8571 <jint/> 8572 <description> 8573 The length of the valid section for this local variable. 8574 The last code array index where the local variable is valid 8575 is <code>start_location + length</code>. 8576 </description> 8577 </field> 8578 <field id="name"> 8579 <allocfieldbuf><char/></allocfieldbuf> 8580 <description> 8581 The local variable name, encoded as a 8582 <internallink id="mUTF">modified UTF-8</internallink> string. 8583 </description> 8584 </field> 8585 <field id="signature"> 8586 <allocfieldbuf><char/></allocfieldbuf> 8587 <description> 8588 The local variable's type signature, encoded as a 8589 <internallink id="mUTF">modified UTF-8</internallink> string. 8590 The signature format is the same as that defined in 8591 <vmspec chapter="4.3.2"/>. 8592 </description> 8593 </field> 8594 <field id="generic_signature"> 8595 <allocfieldbuf><char/></allocfieldbuf> 8596 <description> 8597 The local variable's generic signature, encoded as a 8598 <internallink id="mUTF">modified UTF-8</internallink> string. 8599 The value of this field will be <code>NULL</code> for any local 8600 variable which does not have a generic type. 8601 </description> 8602 </field> 8603 <field id="slot"> 8604 <jint/> 8605 <description> 8606 The local variable's slot. See <internallink id="local">Local Variables</internallink>. 8607 </description> 8608 </field> 8609 </typedef> 8610 <description> 8611 Return local variable information. 8612 </description> 8613 <origin>jvmdiClone</origin> 8614 <capabilities> 8615 <required id="can_access_local_variables"></required> 8616 </capabilities> 8617 <parameters> 8618 <param id="method"> 8619 <jmethodID native="error"/> 8620 <description> 8621 The method to query. 8622 </description> 8623 </param> 8624 <param id="entry_count_ptr"> 8625 <outptr><jint/></outptr> 8626 <description> 8627 On return, points to the number of entries in the table 8628 </description> 8629 </param> 8630 <param id="table_ptr"> 8631 <allocbuf outcount="entry_count_ptr"><struct>jvmtiLocalVariableEntry</struct></allocbuf> 8632 <description> 8633 On return, points to an array of local variable table entries. 8634 </description> 8635 </param> 8636 </parameters> 8637 <errors> 8638 <error id="JVMTI_ERROR_ABSENT_INFORMATION"> 8639 Class information does not include local variable 8640 information. 8641 </error> 8642 </errors> 8643 </function> 8644 8645 <function id="GetBytecodes" phase="start" num="75"> 8646 <synopsis>Get Bytecodes</synopsis> 8647 <description> 8648 For the method indicated by <code>method</code>, 8649 return the byte codes that implement the method. The number of 8650 bytecodes is returned via <code>bytecode_count_ptr</code>. The byte codes 8651 themselves are returned via <code>bytecodes_ptr</code>. 8652 </description> 8653 <origin>jvmdi</origin> 8654 <capabilities> 8655 <required id="can_get_bytecodes"></required> 8656 </capabilities> 8657 <parameters> 8658 <param id="klass"> 8659 <jclass method="method"/> 8660 <description> 8661 The class to query. 8662 </description> 8663 </param> 8664 <param id="method"> 8665 <jmethodID class="klass" native="error"/> 8666 <description> 8667 The method to query. 8668 </description> 8669 </param> 8670 <param id="bytecode_count_ptr"> 8671 <outptr><jint/></outptr> 8672 <description> 8673 On return, points to the length of the byte code array 8674 </description> 8675 </param> 8676 <param id="bytecodes_ptr"> 8677 <allocbuf outcount="bytecode_count_ptr"><uchar/></allocbuf> 8678 <description> 8679 On return, points to the pointer to the byte code array 8680 </description> 8681 </param> 8682 </parameters> 8683 <errors> 8684 </errors> 8685 </function> 8686 8687 <function id="IsMethodNative" phase="start" num="76"> 8688 <synopsis>Is Method Native</synopsis> 8689 <description> 8690 For the method indicated by <code>method</code>, return a 8691 value indicating whether the method is native via <code>is_native_ptr</code> 8692 </description> 8693 <origin>jvmdi</origin> 8694 <capabilities> 8695 </capabilities> 8696 <parameters> 8697 <param id="klass"> 8698 <jclass method="method"/> 8699 <description> 8700 The class to query. 8701 </description> 8702 </param> 8703 <param id="method"> 8704 <jmethodID class="klass"/> 8705 <description> 8706 The method to query. 8707 </description> 8708 </param> 8709 <param id="is_native_ptr"> 8710 <outptr><jboolean/></outptr> 8711 <description> 8712 On return, points to the boolean result of this function. 8713 </description> 8714 </param> 8715 </parameters> 8716 <errors> 8717 </errors> 8718 </function> 8719 8720 <function id="IsMethodSynthetic" phase="start" num="77"> 8721 <synopsis>Is Method Synthetic</synopsis> 8722 <description> 8723 For the method indicated by <code>method</code>, return a 8724 value indicating whether the method is synthetic via <code>is_synthetic_ptr</code>. 8725 Synthetic methods are generated by the compiler but not present in the 8726 original source code. 8727 </description> 8728 <origin>jvmdi</origin> 8729 <capabilities> 8730 <required id="can_get_synthetic_attribute"></required> 8731 </capabilities> 8732 <parameters> 8733 <param id="klass"> 8734 <jclass method="method"/> 8735 <description> 8736 The class to query. 8737 </description> 8738 </param> 8739 <param id="method"> 8740 <jmethodID class="klass"/> 8741 <description> 8742 The method to query. 8743 </description> 8744 </param> 8745 <param id="is_synthetic_ptr"> 8746 <outptr><jboolean/></outptr> 8747 <description> 8748 On return, points to the boolean result of this function. 8749 </description> 8750 </param> 8751 </parameters> 8752 <errors> 8753 </errors> 8754 </function> 8755 8756 <function id="IsMethodObsolete" phase="start" num="91"> 8757 <synopsis>Is Method Obsolete</synopsis> 8758 <description> 8759 Determine if a method ID refers to an 8760 <internallink id="obsoleteMethods">obsolete</internallink> 8761 method version. 8762 </description> 8763 <origin>jvmdi</origin> 8764 <capabilities> 8765 </capabilities> 8766 <parameters> 8767 <param id="klass"> 8768 <jclass method="method"/> 8769 <description> 8770 The class to query. 8771 </description> 8772 </param> 8773 <param id="method"> 8774 <jmethodID class="klass"/> 8775 <description> 8776 The method ID to query. 8777 </description> 8778 </param> 8779 <param id="is_obsolete_ptr"> 8780 <outptr><jboolean/></outptr> 8781 <description> 8782 On return, points to the boolean result of this function. 8783 </description> 8784 </param> 8785 </parameters> 8786 <errors> 8787 </errors> 8788 </function> 8789 8790 <function id="SetNativeMethodPrefix" jkernel="yes" phase="any" num="73" since="1.1"> 8791 <synopsis>Set Native Method Prefix</synopsis> 8792 <description> 8793 This function modifies the failure handling of 8794 native method resolution by allowing retry 8795 with a prefix applied to the name. 8796 When used with the 8797 <eventlink id="ClassFileLoadHook">ClassFileLoadHook 8798 event</eventlink>, it enables native methods to be 8799 <internallink id="bci">instrumented</internallink>. 8800 <p/> 8801 Since native methods cannot be directly instrumented 8802 (they have no bytecodes), they must be wrapped with 8803 a non-native method which can be instrumented. 8804 For example, if we had: 8805 <example> 8806native boolean foo(int x);</example> 8807 <p/> 8808 We could transform the class file (with the 8809 ClassFileLoadHook event) so that this becomes: 8810 <example> 8811boolean foo(int x) { 8812 <i>... record entry to foo ...</i> 8813 return wrapped_foo(x); 8814} 8815 8816native boolean wrapped_foo(int x);</example> 8817 <p/> 8818 Where foo becomes a wrapper for the actual native method 8819 with the appended prefix "wrapped_". Note that 8820 "wrapped_" would be a poor choice of prefix since it 8821 might conceivably form the name of an existing method 8822 thus something like "$$$MyAgentWrapped$$$_" would be 8823 better but would make these examples less readable. 8824 <p/> 8825 The wrapper will allow data to be collected on the native 8826 method call, but now the problem becomes linking up the 8827 wrapped method with the native implementation. 8828 That is, the method <code>wrapped_foo</code> needs to be 8829 resolved to the native implementation of <code>foo</code>, 8830 which might be: 8831 <example> 8832Java_somePackage_someClass_foo(JNIEnv* env, jint x)</example> 8833 <p/> 8834 This function allows the prefix to be specified and the 8835 proper resolution to occur. 8836 Specifically, when the standard resolution fails, the 8837 resolution is retried taking the prefix into consideration. 8838 There are two ways that resolution occurs, explicit 8839 resolution with the JNI function <code>RegisterNatives</code> 8840 and the normal automatic resolution. For 8841 <code>RegisterNatives</code>, the VM will attempt this 8842 association: 8843 <example> 8844method(foo) -> nativeImplementation(foo)</example> 8845 <p/> 8846 When this fails, the resolution will be retried with 8847 the specified prefix prepended to the method name, 8848 yielding the correct resolution: 8849 <example> 8850method(wrapped_foo) -> nativeImplementation(foo)</example> 8851 <p/> 8852 For automatic resolution, the VM will attempt: 8853 <example> 8854method(wrapped_foo) -> nativeImplementation(wrapped_foo)</example> 8855 <p/> 8856 When this fails, the resolution will be retried with 8857 the specified prefix deleted from the implementation name, 8858 yielding the correct resolution: 8859 <example> 8860method(wrapped_foo) -> nativeImplementation(foo)</example> 8861 <p/> 8862 Note that since the prefix is only used when standard 8863 resolution fails, native methods can be wrapped selectively. 8864 <p/> 8865 Since each <jvmti/> environment is independent and 8866 can do its own transformation of the bytecodes, more 8867 than one layer of wrappers may be applied. Thus each 8868 environment needs its own prefix. Since transformations 8869 are applied in order, the prefixes, if applied, will 8870 be applied in the same order. 8871 The order of transformation application is described in 8872 the <eventlink id="ClassFileLoadHook"/> event. 8873 Thus if three environments applied 8874 wrappers, <code>foo</code> might become 8875 <code>$env3_$env2_$env1_foo</code>. But if, say, 8876 the second environment did not apply a wrapper to 8877 <code>foo</code> it would be just 8878 <code>$env3_$env1_foo</code>. To be able to 8879 efficiently determine the sequence of prefixes, 8880 an intermediate prefix is only applied if its non-native 8881 wrapper exists. Thus, in the last example, even though 8882 <code>$env1_foo</code> is not a native method, the 8883 <code>$env1_</code> prefix is applied since 8884 <code>$env1_foo</code> exists. 8885 <p/> 8886 Since the prefixes are used at resolution time 8887 and since resolution may be arbitrarily delayed, a 8888 native method prefix must remain set as long as there 8889 are corresponding prefixed native methods. 8890 </description> 8891 <origin>new</origin> 8892 <capabilities> 8893 <required id="can_set_native_method_prefix"></required> 8894 </capabilities> 8895 <parameters> 8896 <param id="prefix"> 8897 <inbuf> 8898 <char/> 8899 <nullok> 8900 any existing prefix in this environment is cancelled 8901 </nullok> 8902 </inbuf> 8903 <description> 8904 The prefix to apply, encoded as a 8905 <internallink id="mUTF">modified UTF-8</internallink> string. 8906 </description> 8907 </param> 8908 </parameters> 8909 <errors> 8910 </errors> 8911 </function> 8912 8913 <function id="SetNativeMethodPrefixes" jkernel="yes" phase="any" num="74" since="1.1"> 8914 <synopsis>Set Native Method Prefixes</synopsis> 8915 <description> 8916 For a normal agent, <functionlink id="SetNativeMethodPrefix"/> 8917 will provide all needed native method prefixing. 8918 For a meta-agent that performs multiple independent class 8919 file transformations (for example as a proxy for another 8920 layer of agents) this function allows each transformation 8921 to have its own prefix. 8922 The prefixes are applied in the order supplied and are 8923 processed in the same manor as described for the 8924 application of prefixes from multiple <jvmti/> environments 8925 in <functionlink id="SetNativeMethodPrefix"/>. 8926 <p/> 8927 Any previous prefixes are replaced. Thus, calling this 8928 function with a <paramlink id="prefix_count"/> of <code>0</code> 8929 disables prefixing in this environment. 8930 <p/> 8931 <functionlink id="SetNativeMethodPrefix"/> and this function 8932 are the two ways to set the prefixes. 8933 Calling <code>SetNativeMethodPrefix</code> with 8934 a prefix is the same as calling this function with 8935 <paramlink id="prefix_count"/> of <code>1</code>. 8936 Calling <code>SetNativeMethodPrefix</code> with 8937 <code>NULL</code> is the same as calling this function with 8938 <paramlink id="prefix_count"/> of <code>0</code>. 8939 </description> 8940 <origin>new</origin> 8941 <capabilities> 8942 <required id="can_set_native_method_prefix"></required> 8943 </capabilities> 8944 <parameters> 8945 <param id="prefix_count"> 8946 <jint min="0"/> 8947 <description> 8948 The number of prefixes to apply. 8949 </description> 8950 </param> 8951 <param id="prefixes"> 8952 <agentbuf> 8953 <char/> 8954 </agentbuf> 8955 <description> 8956 The prefixes to apply for this environment, each encoded as a 8957 <internallink id="mUTF">modified UTF-8</internallink> string. 8958 </description> 8959 </param> 8960 </parameters> 8961 <errors> 8962 </errors> 8963 </function> 8964 8965 </category> 8966 8967 <category id="RawMonitors" label="Raw Monitor"> 8968 8969 <function id="CreateRawMonitor" phase="onload" callbacksafe="safe" num="31"> 8970 <synopsis>Create Raw Monitor</synopsis> 8971 <description> 8972 Create a raw monitor. 8973 </description> 8974 <origin>jvmdi</origin> 8975 <capabilities> 8976 </capabilities> 8977 <parameters> 8978 <param id="name"> 8979 <inbuf><char/></inbuf> 8980 <description> 8981 A name to identify the monitor, encoded as a 8982 <internallink id="mUTF">modified UTF-8</internallink> string. 8983 </description> 8984 </param> 8985 <param id="monitor_ptr"> 8986 <outptr><jrawMonitorID/></outptr> 8987 <description> 8988 On return, points to the created monitor. 8989 </description> 8990 </param> 8991 </parameters> 8992 <errors> 8993 </errors> 8994 </function> 8995 8996 <function id="DestroyRawMonitor" phase="onload" callbacksafe="safe" num="32"> 8997 <synopsis>Destroy Raw Monitor</synopsis> 8998 <description> 8999 Destroy the raw monitor. 9000 If the monitor being destroyed has been entered by this thread, it will be 9001 exited before it is destroyed. 9002 If the monitor being destroyed has been entered by another thread, 9003 an error will be returned and the monitor will not be destroyed. 9004 </description> 9005 <origin>jvmdi</origin> 9006 <capabilities> 9007 </capabilities> 9008 <parameters> 9009 <param id="monitor"> 9010 <jrawMonitorID/> 9011 <description> 9012 The monitor 9013 </description> 9014 </param> 9015 </parameters> 9016 <errors> 9017 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER"> 9018 Not monitor owner 9019 </error> 9020 </errors> 9021 </function> 9022 9023 <function id="RawMonitorEnter" phase="any" callbacksafe="safe" impl="innative notrace" num="33"> 9024 <synopsis>Raw Monitor Enter</synopsis> 9025 <description> 9026 Gain exclusive ownership of a raw monitor. 9027 The same thread may enter a monitor more then once. 9028 The thread must 9029 <functionlink id="RawMonitorExit">exit</functionlink> 9030 the monitor the same number of times as it is entered. 9031 If a monitor is entered during <code>OnLoad</code> (before attached threads exist) 9032 and has not exited when attached threads come into existence, the enter 9033 is considered to have occurred on the main thread. 9034 </description> 9035 <origin>jvmdi</origin> 9036 <capabilities> 9037 </capabilities> 9038 <parameters> 9039 <param id="monitor"> 9040 <jrawMonitorID/> 9041 <description> 9042 The monitor 9043 </description> 9044 </param> 9045 </parameters> 9046 <errors> 9047 </errors> 9048 </function> 9049 9050 <function id="RawMonitorExit" phase="any" callbacksafe="safe" impl="innative notrace" num="34"> 9051 <synopsis>Raw Monitor Exit</synopsis> 9052 <description> 9053 Release exclusive ownership of a raw monitor. 9054 </description> 9055 <origin>jvmdi</origin> 9056 <capabilities> 9057 </capabilities> 9058 <parameters> 9059 <param id="monitor"> 9060 <jrawMonitorID/> 9061 <description> 9062 The monitor 9063 </description> 9064 </param> 9065 </parameters> 9066 <errors> 9067 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER"> 9068 Not monitor owner 9069 </error> 9070 </errors> 9071 </function> 9072 9073 <function id="RawMonitorWait" phase="any" callbacksafe="safe" impl="innative notrace" num="35"> 9074 <synopsis>Raw Monitor Wait</synopsis> 9075 <description> 9076 Wait for notification of the raw monitor. 9077 <p/> 9078 Causes the current thread to wait until either another thread calls 9079 <functionlink id="RawMonitorNotify"/> or 9080 <functionlink id="RawMonitorNotifyAll"/> 9081 for the specified raw monitor, or the specified 9082 <paramlink id="millis">timeout</paramlink> 9083 has elapsed. 9084 </description> 9085 <origin>jvmdi</origin> 9086 <capabilities> 9087 </capabilities> 9088 <parameters> 9089 <param id="monitor"> 9090 <jrawMonitorID/> 9091 <description> 9092 The monitor 9093 </description> 9094 </param> 9095 <param id="millis"> 9096 <jlong/> 9097 <description> 9098 The timeout, in milliseconds. If the timeout is 9099 zero, then real time is not taken into consideration 9100 and the thread simply waits until notified. 9101 </description> 9102 </param> 9103 </parameters> 9104 <errors> 9105 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER"> 9106 Not monitor owner 9107 </error> 9108 <error id="JVMTI_ERROR_INTERRUPT"> 9109 Wait was interrupted, try again 9110 </error> 9111 </errors> 9112 </function> 9113 9114 <function id="RawMonitorNotify" phase="any" callbacksafe="safe" impl="notrace" num="36"> 9115 <synopsis>Raw Monitor Notify</synopsis> 9116 <description> 9117 Notify a single thread waiting on the raw monitor. 9118 </description> 9119 <origin>jvmdi</origin> 9120 <capabilities> 9121 </capabilities> 9122 <parameters> 9123 <param id="monitor"> 9124 <jrawMonitorID/> 9125 <description> 9126 The monitor 9127 </description> 9128 </param> 9129 </parameters> 9130 <errors> 9131 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER"> 9132 Not monitor owner 9133 </error> 9134 </errors> 9135 </function> 9136 9137 <function id="RawMonitorNotifyAll" phase="any" callbacksafe="safe" impl="notrace" num="37"> 9138 <synopsis>Raw Monitor Notify All</synopsis> 9139 <description> 9140 Notify all threads waiting on the raw monitor. 9141 </description> 9142 <origin>jvmdi</origin> 9143 <capabilities> 9144 </capabilities> 9145 <parameters> 9146 <param id="monitor"> 9147 <jrawMonitorID/> 9148 <description> 9149 The monitor 9150 </description> 9151 </param> 9152 </parameters> 9153 <errors> 9154 <error id="JVMTI_ERROR_NOT_MONITOR_OWNER"> 9155 Not monitor owner 9156 </error> 9157 </errors> 9158 </function> 9159 9160 <elide> 9161 <function id="GetRawMonitorUse" num="118"> 9162 <synopsis>Get Raw Monitor Use</synopsis> 9163 <description> 9164 The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure 9165 are filled in with information about usage of the raw monitor. 9166 </description> 9167 <origin>new</origin> 9168 <capabilities> 9169 <required id="can_get_raw_monitor_usage"></required> 9170 </capabilities> 9171 <parameters> 9172 <param id="monitor"> 9173 <jrawMonitorID/> 9174 <description> 9175 the raw monitor to query. 9176 </description> 9177 </param> 9178 <param id="info_ptr"> 9179 <outptr><struct>jvmtiMonitorUsage</struct></outptr> 9180 <description> 9181 On return, filled with monitor information for the 9182 specified raw monitor. 9183 </description> 9184 </param> 9185 </parameters> 9186 <errors> 9187 </errors> 9188 </function> 9189 9190 <function id="GetRawMonitors" num="119"> 9191 <synopsis>Get Raw Monitors</synopsis> 9192 <description> 9193 Return the list of raw monitors. 9194 <p/> 9195 Note: details about each monitor can be examined with 9196 <functionlink id="GetRawMonitorUse"></functionlink>. 9197 </description> 9198 <origin>new</origin> 9199 <capabilities> 9200 <required id="can_get_raw_monitor_usage"></required> 9201 </capabilities> 9202 <parameters> 9203 <param id="monitorCnt"> 9204 <outptr><jint/></outptr> 9205 <description> 9206 On return, pointer to the number 9207 of monitors returned in <code>monitors_ptr</code>. 9208 </description> 9209 </param> 9210 <param id="monitors_ptr"> 9211 <allocbuf outcount="monitorCnt"><jrawMonitorID/></allocbuf> 9212 <description> 9213 On return, pointer to the monitor list. 9214 </description> 9215 </param> 9216 </parameters> 9217 <errors> 9218 </errors> 9219 </function> 9220 </elide> 9221 </category> 9222 9223 <category id="jniIntercept" label="JNI Function Interception"> 9224 9225 <intro> 9226 Provides the ability to intercept and resend 9227 Java Native Interface (JNI) function calls 9228 by manipulating the JNI function table. 9229 See <externallink id="jni/functions.html">JNI 9230 Functions</externallink> in the <i>Java Native Interface Specification</i>. 9231 <p/> 9232 The following example illustrates intercepting the 9233 <code>NewGlobalRef</code> JNI call in order to count reference 9234 creation. 9235 <example> 9236JNIEnv original_jni_Functions; 9237JNIEnv redirected_jni_Functions; 9238int my_global_ref_count = 0; 9239 9240jobject 9241MyNewGlobalRef(JNIEnv *jni_env, jobject lobj) { 9242 ++my_global_ref_count; 9243 return originalJNIFunctions->NewGlobalRef(env, lobj); 9244} 9245 9246void 9247myInit() { 9248 jvmtiError err; 9249 9250 err = (*jvmti_env)->GetJNIFunctionTable(jvmti_env, &original_jni_Functions); 9251 if (err != JVMTI_ERROR_NONE) { 9252 die(); 9253 } 9254 err = (*jvmti_env)->GetJNIFunctionTable(jvmti_env, &redirected_jni_Functions); 9255 if (err != JVMTI_ERROR_NONE) { 9256 die(); 9257 } 9258 redirectedJNIFunctions->NewGlobalRef = MyNewGlobalRef; 9259 err = (*jvmti_env)->SetJNIFunctionTable(jvmti_env, redirected_jni_Functions); 9260 if (err != JVMTI_ERROR_NONE) { 9261 die(); 9262 } 9263} 9264 </example> 9265 Sometime after <code>myInit</code> is called the user's JNI 9266 code is executed which makes the call to create a new global 9267 reference. Instead of going to the normal JNI implementation 9268 the call goes to <code>myNewGlobalRef</code>. Note that a 9269 copy of the original function table is kept so that the normal 9270 JNI function can be called after the data is collected. 9271 Note also that any JNI functions which are not overwritten 9272 will behave normally. 9273 <todo> 9274 check that the example compiles and executes. 9275 </todo> 9276 </intro> 9277 9278 <function id="SetJNIFunctionTable" phase="start" num="120"> 9279 <synopsis>Set JNI Function Table</synopsis> 9280 <description> 9281 Set the JNI function table 9282 in all current and future JNI environments. 9283 As a result, all future JNI calls are directed to the specified functions. 9284 Use <functionlink id="GetJNIFunctionTable"></functionlink> to get the 9285 function table to pass to this function. 9286 For this function to take effect the the updated table entries must be 9287 used by the JNI clients. 9288 Since the table is defined <code>const</code> some compilers may optimize 9289 away the access to the table, thus preventing this function from taking 9290 effect. 9291 The table is copied--changes to the local copy of the 9292 table have no effect. 9293 This function affects only the function table, all other aspects of the environment are 9294 unaffected. 9295 See the examples <internallink id="jniIntercept">above</internallink>. 9296 </description> 9297 <origin>new</origin> 9298 <capabilities> 9299 </capabilities> 9300 <parameters> 9301 <param id="function_table"> 9302 <inptr> 9303 <struct>jniNativeInterface</struct> 9304 </inptr> 9305 <description> 9306 Points to the new JNI function table. 9307 </description> 9308 </param> 9309 </parameters> 9310 <errors> 9311 </errors> 9312 </function> 9313 9314 <function id="GetJNIFunctionTable" phase="start" num="121"> 9315 <synopsis>Get JNI Function Table</synopsis> 9316 <description> 9317 Get the JNI function table. 9318 The JNI function table is copied into allocated memory. 9319 If <functionlink id="SetJNIFunctionTable"></functionlink> 9320 has been called, the modified (not the original) function 9321 table is returned. 9322 Only the function table is copied, no other aspects of the environment 9323 are copied. 9324 See the examples <internallink id="jniIntercept">above</internallink>. 9325 </description> 9326 <origin>new</origin> 9327 <capabilities> 9328 </capabilities> 9329 <parameters> 9330 <param id="function_table"> 9331 <allocbuf> 9332 <struct>jniNativeInterface</struct> 9333 </allocbuf> 9334 <description> 9335 On return, <code>*function_table</code> 9336 points a newly allocated copy of the JNI function table. 9337 </description> 9338 </param> 9339 </parameters> 9340 <errors> 9341 </errors> 9342 </function> 9343 9344 </category> 9345 9346 <category id="eventManagement" label="Event Management"> 9347 9348 <function id="SetEventCallbacks" jkernel="yes" phase="onload" num="122"> 9349 <synopsis>Set Event Callbacks</synopsis> 9350 <description> 9351 Set the functions to be called for each event. 9352 The callbacks are specified by supplying a replacement function table. 9353 The function table is copied--changes to the local copy of the 9354 table have no effect. 9355 This is an atomic action, all callbacks are set at once. 9356 No events are sent before this function is called. 9357 When an entry is <code>NULL</code> or when the event is beyond 9358 <paramlink id="size_of_callbacks"></paramlink> no event is sent. 9359 Details on events are 9360 described <internallink id="EventSection">later</internallink> in this document. 9361 An event must be enabled and have a callback in order to be 9362 sent--the order in which this function and 9363 <functionlink id="SetEventNotificationMode"></functionlink> 9364 are called does not affect the result. 9365 </description> 9366 <origin>new</origin> 9367 <capabilities> 9368 </capabilities> 9369 <parameters> 9370 <param id="callbacks"> 9371 <inptr> 9372 <struct>jvmtiEventCallbacks</struct> 9373 <nullok>remove the existing callbacks</nullok> 9374 </inptr> 9375 <description> 9376 The new event callbacks. 9377 </description> 9378 </param> 9379 <param id="size_of_callbacks"> 9380 <jint min="0"/> 9381 <description> 9382 <code>sizeof(jvmtiEventCallbacks)</code>--for version 9383 compatibility. 9384 </description> 9385 </param> 9386 </parameters> 9387 <errors> 9388 </errors> 9389 </function> 9390 9391 <function id="SetEventNotificationMode" jkernel="yes" phase="onload" num="2"> 9392 <synopsis>Set Event Notification Mode</synopsis> 9393 <description> 9394 Control the generation of events. 9395 <constants id="jvmtiEventMode" label="Event Enable/Disable" kind="enum"> 9396 <constant id="JVMTI_ENABLE" num="1"> 9397 If <paramlink id="mode"></paramlink> is <code>JVMTI_ENABLE</code>, 9398 the event <paramlink id="event_type"></paramlink> will be enabled 9399 </constant> 9400 <constant id="JVMTI_DISABLE" num="0"> 9401 If <paramlink id="mode"></paramlink> is <code>JVMTI_DISABLE</code>, 9402 the event <paramlink id="event_type"></paramlink> will be disabled 9403 </constant> 9404 </constants> 9405 If <code>thread</code> is <code>NULL</code>, 9406 the event is enabled or disabled globally; otherwise, it is 9407 enabled or disabled for a particular thread. 9408 An event is generated for 9409 a particular thread if it is enabled either at the thread or global 9410 levels. 9411 <p/> 9412 See <internallink id="EventIndex">below</internallink> for information on specific events. 9413 <p/> 9414 The following events cannot be controlled at the thread 9415 level through this function. 9416 <ul> 9417 <li><eventlink id="VMInit"></eventlink></li> 9418 <li><eventlink id="VMStart"></eventlink></li> 9419 <li><eventlink id="VMDeath"></eventlink></li> 9420 <li><eventlink id="ThreadStart"></eventlink></li> 9421 <li><eventlink id="CompiledMethodLoad"></eventlink></li> 9422 <li><eventlink id="CompiledMethodUnload"></eventlink></li> 9423 <li><eventlink id="DynamicCodeGenerated"></eventlink></li> 9424 <li><eventlink id="DataDumpRequest"></eventlink></li> 9425 </ul> 9426 <p/> 9427 Initially, no events are enabled at either the thread level 9428 or the global level. 9429 <p/> 9430 Any needed capabilities (see Event Enabling Capabilities below) must be possessed 9431 before calling this function. 9432 <p/> 9433 Details on events are 9434 described <internallink id="EventSection">below</internallink>. 9435 </description> 9436 <origin>jvmdiClone</origin> 9437 <eventcapabilities></eventcapabilities> 9438 <parameters> 9439 <param id="mode"> 9440 <enum>jvmtiEventMode</enum> 9441 <description> 9442 <code>JVMTI_ENABLE</code> or <code>JVMTI_DISABLE</code> 9443 </description> 9444 </param> 9445 <param id="event_type"> 9446 <enum>jvmtiEvent</enum> 9447 <description> 9448 the event to control 9449 </description> 9450 </param> 9451 <param id="event_thread"> 9452 <ptrtype> 9453 <jthread impl="noconvert"/> 9454 <nullok>event is controlled at the global level</nullok> 9455 </ptrtype> 9456 <description> 9457 The thread to control 9458 </description> 9459 </param> 9460 <param id="..."> 9461 <varargs/> 9462 <description> 9463 for future expansion 9464 </description> 9465 </param> 9466 </parameters> 9467 <errors> 9468 <error id="JVMTI_ERROR_INVALID_THREAD"> 9469 <paramlink id="event_thread"/> is non-<code>NULL</code> and is not a valid thread. 9470 </error> 9471 <error id="JVMTI_ERROR_THREAD_NOT_ALIVE"> 9472 <paramlink id="event_thread"/> is non-<code>NULL</code> and is not live (has not been started or is now dead). 9473 </error> 9474 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 9475 thread level control was attempted on events which do not 9476 permit thread level control. 9477 </error> 9478 <error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY"> 9479 The Required Event Enabling Capability is not possessed. 9480 </error> 9481 </errors> 9482 </function> 9483 9484 <function id="GenerateEvents" num="123"> 9485 <synopsis>Generate Events</synopsis> 9486 <description> 9487 Generate events to represent the current state of the VM. 9488 For example, if <paramlink id="event_type"/> is 9489 <code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code>, 9490 a <eventlink id="CompiledMethodLoad"></eventlink> event will be 9491 sent for each currently compiled method. 9492 Methods that were loaded and now have been unloaded are not sent. 9493 The history of what events have previously been sent does not 9494 effect what events are sent by this function--for example, 9495 all currently compiled methods 9496 will be sent each time this function is called. 9497 <p/> 9498 This function is useful when 9499 events may have been missed due to the agent attaching after program 9500 execution begins; this function generates the missed events. 9501 <p/> 9502 Attempts to execute Java programming language code or 9503 JNI functions may be paused until this function returns - 9504 so neither should be called from the thread sending the event. 9505 This function returns only after the missed events have been 9506 sent, processed and have returned. 9507 The event may be sent on a different thread than the thread 9508 on which the event occurred. 9509 The callback for the event must be set with 9510 <functionlink id="SetEventCallbacks"></functionlink> 9511 and the event must be enabled with 9512 <functionlink id="SetEventNotificationMode"></functionlink> 9513 or the events will not occur. 9514 If the VM no longer has the information to generate some or 9515 all of the requested events, the events are simply not sent - 9516 no error is returned. 9517 <p/> 9518 Only the following events are supported: 9519 <ul> 9520 <li><eventlink id="CompiledMethodLoad"></eventlink></li> 9521 <li><eventlink id="DynamicCodeGenerated"></eventlink></li> 9522 </ul> 9523 </description> 9524 <origin>new</origin> 9525 <capabilities> 9526 <capability id="can_generate_compiled_method_load_events"></capability> 9527 </capabilities> 9528 <parameters> 9529 <param id="event_type"> 9530 <enum>jvmtiEvent</enum> 9531 <description> 9532 The type of event to generate. Must be one of these: 9533 <ul> 9534 <li><eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink></li> 9535 <li><eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink></li> 9536 </ul> 9537 </description> 9538 </param> 9539 </parameters> 9540 <errors> 9541 <error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY"> 9542 <paramlink id="event_type"/> is 9543 <eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink> 9544 and <fieldlink id="can_generate_compiled_method_load_events" struct="jvmtiCapabilities"></fieldlink> 9545 is <code>false</code>. 9546 </error> 9547 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 9548 <paramlink id="event_type"/> is other than 9549 <eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink> 9550 or <eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink>. 9551 </error> 9552 </errors> 9553 </function> 9554 9555 </category> 9556 9557 <category id="extension" label="Extension Mechanism"> 9558 9559 <intro> 9560 These functions 9561 allow a <jvmti/> implementation to provide functions and events 9562 beyond those defined in this specification. 9563 <p/> 9564 Both extension functions and extension events have parameters 9565 each of which has a 'type' and 'kind' chosen from the following tables: 9566 9567 <constants id="jvmtiParamTypes" label="Extension Function/Event Parameter Types" kind="enum"> 9568 <constant id="JVMTI_TYPE_JBYTE" num="101"> 9569 Java programming language primitive type - <code>byte</code>. 9570 JNI type <code>jbyte</code>. 9571 </constant> 9572 <constant id="JVMTI_TYPE_JCHAR" num="102"> 9573 Java programming language primitive type - <code>char</code>. 9574 JNI type <code>jchar</code>. 9575 </constant> 9576 <constant id="JVMTI_TYPE_JSHORT" num="103"> 9577 Java programming language primitive type - <code>short</code>. 9578 JNI type <code>jshort</code>. 9579 </constant> 9580 <constant id="JVMTI_TYPE_JINT" num="104"> 9581 Java programming language primitive type - <code>int</code>. 9582 JNI type <datalink id="jint"></datalink>. 9583 </constant> 9584 <constant id="JVMTI_TYPE_JLONG" num="105"> 9585 Java programming language primitive type - <code>long</code>. 9586 JNI type <datalink id="jlong"></datalink>. 9587 </constant> 9588 <constant id="JVMTI_TYPE_JFLOAT" num="106"> 9589 Java programming language primitive type - <code>float</code>. 9590 JNI type <datalink id="jfloat"></datalink>. 9591 </constant> 9592 <constant id="JVMTI_TYPE_JDOUBLE" num="107"> 9593 Java programming language primitive type - <code>double</code>. 9594 JNI type <datalink id="jdouble"></datalink>. 9595 </constant> 9596 <constant id="JVMTI_TYPE_JBOOLEAN" num="108"> 9597 Java programming language primitive type - <code>boolean</code>. 9598 JNI type <datalink id="jboolean"></datalink>. 9599 </constant> 9600 <constant id="JVMTI_TYPE_JOBJECT" num="109"> 9601 Java programming language object type - <code>java.lang.Object</code>. 9602 JNI type <datalink id="jobject"></datalink>. 9603 Returned values are JNI local references and must be managed. 9604 </constant> 9605 <constant id="JVMTI_TYPE_JTHREAD" num="110"> 9606 Java programming language object type - <code>java.lang.Thread</code>. 9607 <jvmti/> type <datalink id="jthread"></datalink>. 9608 Returned values are JNI local references and must be managed. 9609 </constant> 9610 <constant id="JVMTI_TYPE_JCLASS" num="111"> 9611 Java programming language object type - <code>java.lang.Class</code>. 9612 JNI type <datalink id="jclass"></datalink>. 9613 Returned values are JNI local references and must be managed. 9614 </constant> 9615 <constant id="JVMTI_TYPE_JVALUE" num="112"> 9616 Union of all Java programming language primitive and object types - 9617 JNI type <datalink id="jvalue"></datalink>. 9618 Returned values which represent object types are JNI local references and must be managed. 9619 </constant> 9620 <constant id="JVMTI_TYPE_JFIELDID" num="113"> 9621 Java programming language field identifier - 9622 JNI type <datalink id="jfieldID"></datalink>. 9623 </constant> 9624 <constant id="JVMTI_TYPE_JMETHODID" num="114"> 9625 Java programming language method identifier - 9626 JNI type <datalink id="jmethodID"></datalink>. 9627 </constant> 9628 <constant id="JVMTI_TYPE_CCHAR" num="115"> 9629 C programming language type - <code>char</code>. 9630 </constant> 9631 <constant id="JVMTI_TYPE_CVOID" num="116"> 9632 C programming language type - <code>void</code>. 9633 </constant> 9634 <constant id="JVMTI_TYPE_JNIENV" num="117"> 9635 JNI environment - <code>JNIEnv</code>. 9636 Should be used with the correct <datalink id="jvmtiParamKind"/> to make it a pointer type. 9637 </constant> 9638 </constants> 9639 9640 <constants id="jvmtiParamKind" label="Extension Function/Event Parameter Kinds" kind="enum"> 9641 <constant id="JVMTI_KIND_IN" num="91"> 9642 Ingoing argument - <code>foo</code>. 9643 </constant> 9644 <constant id="JVMTI_KIND_IN_PTR" num="92"> 9645 Ingoing pointer argument - <code>const foo*</code>. 9646 </constant> 9647 <constant id="JVMTI_KIND_IN_BUF" num="93"> 9648 Ingoing array argument - <code>const foo*</code>. 9649 </constant> 9650 <constant id="JVMTI_KIND_ALLOC_BUF" num="94"> 9651 Outgoing allocated array argument - <code>foo**</code>. 9652 Free with <code>Deallocate</code>. 9653 </constant> 9654 <constant id="JVMTI_KIND_ALLOC_ALLOC_BUF" num="95"> 9655 Outgoing allocated array of allocated arrays argument - <code>foo***</code>. 9656 Free with <code>Deallocate</code>. 9657 </constant> 9658 <constant id="JVMTI_KIND_OUT" num="96"> 9659 Outgoing argument - <code>foo*</code>. 9660 </constant> 9661 <constant id="JVMTI_KIND_OUT_BUF" num="97"> 9662 Outgoing array argument (pre-allocated by agent) - <code>foo*</code>. 9663 Do not <code>Deallocate</code>. 9664 </constant> 9665 </constants> 9666 9667 </intro> 9668 9669 <typedef id="jvmtiParamInfo" label="Extension Function/Event Parameter Info"> 9670 <field id="name"> 9671 <allocfieldbuf><char/></allocfieldbuf> 9672 <description> 9673 The parameter name, encoded as a 9674 <internallink id="mUTF">modified UTF-8</internallink> string 9675 </description> 9676 </field> 9677 <field id="kind"> 9678 <enum>jvmtiParamKind</enum> 9679 <description> 9680 The kind of the parameter - type modifiers 9681 </description> 9682 </field> 9683 <field id="base_type"> 9684 <enum>jvmtiParamTypes</enum> 9685 <description> 9686 The base type of the parameter - modified by <code>kind</code> 9687 </description> 9688 </field> 9689 <field id="null_ok"> 9690 <jboolean/> 9691 <description> 9692 Is a <code>NULL</code> argument permitted? Applies only to pointer and object types. 9693 </description> 9694 </field> 9695 </typedef> 9696 9697 <callback id="jvmtiExtensionFunction"> 9698 <enum>jvmtiError</enum> 9699 <synopsis>Extension Function</synopsis> 9700 <description> 9701 This is the implementation-specific extension function. 9702 </description> 9703 <parameters> 9704 <param id="jvmti_env"> 9705 <outptr> 9706 <struct>jvmtiEnv</struct> 9707 </outptr> 9708 <description> 9709 The <jvmti/> environment is the only fixed parameter for extension functions. 9710 </description> 9711 </param> 9712 <param id="..."> 9713 <varargs/> 9714 <description> 9715 The extension function-specific parameters 9716 </description> 9717 </param> 9718 </parameters> 9719 </callback> 9720 9721 <function id="GetExtensionFunctions" phase="onload" num="124"> 9722 <synopsis>Get Extension Functions</synopsis> 9723 9724 <typedef id="jvmtiExtensionFunctionInfo" label="Extension Function Info"> 9725 <field id="func"> 9726 <ptrtype> 9727 <struct>jvmtiExtensionFunction</struct> 9728 </ptrtype> 9729 <description> 9730 The actual function to call 9731 </description> 9732 </field> 9733 <field id="id"> 9734 <allocfieldbuf><char/></allocfieldbuf> 9735 <description> 9736 The identifier for the extension function, encoded as a 9737 <internallink id="mUTF">modified UTF-8</internallink> string. 9738 Uses package name conventions. 9739 For example, <code>com.sun.hotspot.bar</code> 9740 </description> 9741 </field> 9742 <field id="short_description"> 9743 <allocfieldbuf><char/></allocfieldbuf> 9744 <description> 9745 A one sentence description of the function, encoded as a 9746 <internallink id="mUTF">modified UTF-8</internallink> string. 9747 </description> 9748 </field> 9749 <field id="param_count"> 9750 <jint/> 9751 <description> 9752 The number of parameters excluding <code>jvmtiEnv *jvmti_env</code> 9753 </description> 9754 </field> 9755 <field id="params"> 9756 <allocfieldbuf outcount="param_count"> 9757 <struct>jvmtiParamInfo</struct> 9758 </allocfieldbuf> 9759 <description> 9760 Array of 9761 <fieldlink id="param_count" struct="jvmtiExtensionFunctionInfo"></fieldlink> 9762 parameters (<code>jvmtiEnv *jvmti_env</code> excluded) 9763 </description> 9764 </field> 9765 <field id="error_count"> 9766 <jint/> 9767 <description> 9768 The number of possible error returns (excluding universal errors) 9769 </description> 9770 </field> 9771 <field id="errors"> 9772 <allocfieldbuf outcount="error_count"> 9773 <enum>jvmtiError</enum> 9774 </allocfieldbuf> 9775 <description> 9776 Array of <fieldlink id="error_count" struct="jvmtiExtensionFunctionInfo"></fieldlink> 9777 possible errors 9778 </description> 9779 </field> 9780 </typedef> 9781 9782 <description> 9783 Returns the set of extension functions. 9784 </description> 9785 <origin>new</origin> 9786 <capabilities> 9787 </capabilities> 9788 <parameters> 9789 <param id="extension_count_ptr"> 9790 <outptr><jint/></outptr> 9791 <description> 9792 On return, points to the number of extension functions 9793 </description> 9794 </param> 9795 <param id="extensions"> 9796 <allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionFunctionInfo</struct></allocbuf> 9797 <description> 9798 Returns an array of extension function info, one per function 9799 </description> 9800 </param> 9801 </parameters> 9802 <errors> 9803 </errors> 9804 </function> 9805 9806 <function id="GetExtensionEvents" phase="onload" num="125"> 9807 <synopsis>Get Extension Events</synopsis> 9808 9809 <typedef id="jvmtiExtensionEventInfo" label="Extension Event Info"> 9810 <field id="extension_event_index"> 9811 <jint/> 9812 <description> 9813 The identifying index of the event 9814 </description> 9815 </field> 9816 <field id="id"> 9817 <allocfieldbuf><char/></allocfieldbuf> 9818 <description> 9819 The identifier for the extension event, encoded as a 9820 <internallink id="mUTF">modified UTF-8</internallink> string. 9821 Uses package name conventions. 9822 For example, <code>com.sun.hotspot.bar</code> 9823 </description> 9824 </field> 9825 <field id="short_description"> 9826 <allocfieldbuf><char/></allocfieldbuf> 9827 <description> 9828 A one sentence description of the event, encoded as a 9829 <internallink id="mUTF">modified UTF-8</internallink> string. 9830 </description> 9831 </field> 9832 <field id="param_count"> 9833 <jint/> 9834 <description> 9835 The number of parameters excluding <code>jvmtiEnv *jvmti_env</code> 9836 </description> 9837 </field> 9838 <field id="params"> 9839 <allocfieldbuf outcount="param_count"> 9840 <struct>jvmtiParamInfo</struct> 9841 </allocfieldbuf> 9842 <description> 9843 Array of 9844 <fieldlink id="param_count" struct="jvmtiExtensionEventInfo"></fieldlink> 9845 parameters (<code>jvmtiEnv *jvmti_env</code> excluded) 9846 </description> 9847 </field> 9848 </typedef> 9849 9850 <description> 9851 Returns the set of extension events. 9852 </description> 9853 <origin>new</origin> 9854 <capabilities> 9855 </capabilities> 9856 <parameters> 9857 <param id="extension_count_ptr"> 9858 <outptr><jint/></outptr> 9859 <description> 9860 On return, points to the number of extension events 9861 </description> 9862 </param> 9863 <param id="extensions"> 9864 <allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionEventInfo</struct></allocbuf> 9865 <description> 9866 Returns an array of extension event info, one per event 9867 </description> 9868 </param> 9869 </parameters> 9870 <errors> 9871 </errors> 9872 </function> 9873 9874 <callback id="jvmtiExtensionEvent"> 9875 <void/> 9876 <synopsis>Extension Event</synopsis> 9877 <description> 9878 This is the implementation-specific event. 9879 The event handler is set with 9880 <functionlink id="SetExtensionEventCallback"/>. 9881 <p/> 9882 Event handlers for extension events must be declared varargs to match this definition. 9883 Failure to do so could result in calling convention mismatch and undefined behavior 9884 on some platforms. 9885 <p/> 9886 For example, if the <code>jvmtiParamInfo</code> 9887 returned by <functionlink id="GetExtensionEvents"/> indicates that 9888 there is a <code>jint</code> parameter, the event handler should be 9889 declared: 9890<example> 9891 void JNICALL myHandler(jvmtiEnv* jvmti_env, jint myInt, ...) 9892</example> 9893 Note the terminal "<code>...</code>" which indicates varargs. 9894 </description> 9895 <parameters> 9896 <param id="jvmti_env"> 9897 <outptr> 9898 <struct>jvmtiEnv</struct> 9899 </outptr> 9900 <description> 9901 The <jvmti/> environment is the only fixed parameter for extension events. 9902 </description> 9903 </param> 9904 <param id="..."> 9905 <varargs/> 9906 <description> 9907 The extension event-specific parameters 9908 </description> 9909 </param> 9910 </parameters> 9911 </callback> 9912 9913 <function id="SetExtensionEventCallback" phase="onload" num="126"> 9914 <synopsis>Set Extension Event Callback</synopsis> 9915 9916 <description> 9917 Sets the callback function for an extension event and 9918 enables the event. Or, if the callback is <code>NULL</code>, disables 9919 the event. Note that unlike standard events, setting 9920 the callback and enabling the event are a single operation. 9921 </description> 9922 <origin>new</origin> 9923 <capabilities> 9924 </capabilities> 9925 <parameters> 9926 <param id="extension_event_index"> 9927 <jint/> 9928 <description> 9929 Identifies which callback to set. 9930 This index is the 9931 <fieldlink id="extension_event_index" struct="jvmtiExtensionEventInfo"></fieldlink> 9932 field of 9933 <datalink id="jvmtiExtensionEventInfo"/>. 9934 </description> 9935 </param> 9936 <param id="callback"> 9937 <ptrtype> 9938 <struct>jvmtiExtensionEvent</struct> 9939 <nullok>disable the event</nullok> 9940 </ptrtype> 9941 <description> 9942 If <code>callback</code> is non-<code>NULL</code>, 9943 set <code>callback</code> to be the event callback function 9944 and enable the event. 9945 </description> 9946 </param> 9947 </parameters> 9948 <errors> 9949 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 9950 <paramlink id="extension_event_index"/> is not an 9951 <fieldlink id="extension_event_index" 9952 struct="jvmtiExtensionEventInfo"/> 9953 returned by 9954 <functionlink id="GetExtensionEvents"/> 9955 </error> 9956 </errors> 9957 </function> 9958 9959 </category> 9960 9961 <category id="capability" label="Capability"> 9962 9963 <intro> 9964 The capabilities functions allow you to change the 9965 functionality available to <jvmti/>--that is, 9966 which <jvmti/> 9967 functions can be called, what events can be generated, 9968 and what functionality these events and functions can 9969 provide. 9970 <p/> 9971 The "Capabilities" section of each function and event describe which 9972 capabilities, if any, they are associated with. "Required Functionality" 9973 means it is available for use and no capabilities must be added to use it. 9974 "Optional Functionality" means the agent must possess the capability 9975 before it can be used. 9976 To possess a capability, the agent must 9977 <functionlink id="AddCapabilities">add the capability</functionlink>. 9978 "Optional Features" describe capabilities which, 9979 if added, extend the feature set. 9980 <p/> 9981 The potentially available capabilities of each <jvmti/> implementation are different. 9982 Depending on the implementation, a capability: 9983 <ul> 9984 <li>may never be added</li> 9985 <li>may be added in either the <code>OnLoad</code> or live phase in any environment</li> 9986 <li>may be added only during the <code>OnLoad</code> phase</li> 9987 <li>may be possessed by only one environment at a time</li> 9988 <li>may be possessed by only one environment at a time, 9989 and only during the <code>OnLoad</code> phase</li> 9990 <li>and so on ...</li> 9991 </ul> 9992 Frequently, the addition of a capability may incur a cost in execution speed, start up 9993 time, and/or memory footprint. Note that the overhead of using a capability 9994 is completely different than the overhead of possessing a capability. 9995 Take single stepping as an example. When single stepping is on (that 9996 is, when the event is enabled and thus actively sending events) 9997 the overhead of sending and processing an event 9998 on each instruction is huge in any implementation. 9999 However, the overhead of possessing the capability may be small or large, 10000 depending on the implementation. Also, when and if a capability is potentially 10001 available depends on the implementation. Some examples: 10002 <ul> 10003 <li>One VM might perform all execution by compiling bytecodes into 10004 native code and be unable to generate single step instructions. 10005 In this implementation the capability can not be added.</li> 10006 <li>Another VM may be able to switch execution to a single stepping 10007 interpreter at any time. In this implementation, having the capability has no 10008 overhead and could be added at any time.</li> 10009 <li>Yet another VM might be able to choose a bytecode compiling or single stepping capable interpreted 10010 execution engine at start up, but be unable to switch between them. 10011 In this implementation the capability would need to be added 10012 during the <code>OnLoad</code> phase (before bytecode 10013 execution begins) and would have a large impact on execution speed 10014 even if single stepping was never used.</li> 10015 <li>Still another VM might be able to add an "is single stepping on" check 10016 into compiled bytecodes or a generated interpreter. Again in this implementation 10017 the capability would need to be added during the <code>OnLoad</code> phase but the overhead (a test 10018 and branch on each instruction) would be considerably less.</li> 10019 </ul> 10020 <p/> 10021 Each <jvmti/> <internallink id="environments">environment</internallink> 10022 has its own set of capabilities. 10023 Initially, that set is empty. 10024 Any desired capability must be added. 10025 If possible, capabilities should be added during the <code>OnLoad</code> phase. For most 10026 virtual machines certain capabilities require special set up for 10027 the virtual machine and this set up must happen 10028 during the <code>OnLoad</code> phase, before the virtual machine begins execution. 10029 Once a capability is added, it can 10030 only be removed if explicitly relinquished by the environment. 10031 <p/> 10032 The agent can, 10033 <functionlink id="GetPotentialCapabilities">determine what 10034 capabilities this VM can potentially provide</functionlink>, 10035 <functionlink id="AddCapabilities">add the capabilities 10036 to be used</functionlink>, 10037 <functionlink id="RelinquishCapabilities">release capabilities 10038 which are no longer needed</functionlink>, and 10039 <functionlink id="GetCapabilities">examine the currently available 10040 capabilities</functionlink>. 10041 </intro> 10042 10043 <intro id="capabilityExamples" label="Capability Examples"> 10044 For example, a freshly started agent (in the <code>OnLoad</code> function) 10045 wants to enable all possible capabilities. 10046 Note that, in general, this is not advisable as the agent may suffer 10047 a performance penalty for functionality it is not using. 10048 The code might look like this in C: 10049 <example> 10050 jvmtiCapabilities capa; 10051 jvmtiError err; 10052 10053 err = (*jvmti)->GetPotentialCapabilities(jvmti, &capa); 10054 if (err == JVMTI_ERROR_NONE) { 10055 err = (*jvmti)->AddCapabilities(jvmti, &capa); 10056 </example> 10057 For example, if an agent wants to check if it can get 10058 the bytecodes of a method (that is, it wants to check 10059 if it previously added this capability and has not 10060 relinquished it), the code might 10061 look like this in C: 10062 <example> 10063 jvmtiCapabilities capa; 10064 jvmtiError err; 10065 10066 err = (*jvmti)->GetCapabilities(jvmti, &capa); 10067 if (err == JVMTI_ERROR_NONE) { 10068 if (capa.can_get_bytecodes) { ... } } 10069 </example> 10070 </intro> 10071 10072 <capabilitiestypedef id="jvmtiCapabilities" label="The Capabilities Structure"> 10073 <description> 10074 The functions in this category use this capabilities structure 10075 which contains boolean flags corresponding to each capability: 10076 </description> 10077 <capabilityfield id="can_tag_objects"> 10078 <description> 10079 Can set and get tags, as described in the 10080 <internallink id="Heap">Heap category</internallink>. 10081 </description> 10082 </capabilityfield> 10083 <capabilityfield id="can_generate_field_modification_events"> 10084 <description> 10085 Can set watchpoints on field modification - 10086 <functionlink id="SetFieldModificationWatch"></functionlink> 10087 </description> 10088 </capabilityfield> 10089 <capabilityfield id="can_generate_field_access_events"> 10090 <description> 10091 Can set watchpoints on field access - 10092 <functionlink id="SetFieldAccessWatch"></functionlink> 10093 </description> 10094 </capabilityfield> 10095 <capabilityfield id="can_get_bytecodes"> 10096 <description> 10097 Can get bytecodes of a method <functionlink id="GetBytecodes"></functionlink> 10098 </description> 10099 </capabilityfield> 10100 <capabilityfield id="can_get_synthetic_attribute"> 10101 <description> 10102 Can test if a field or method is synthetic - 10103 <functionlink id="IsFieldSynthetic"></functionlink> and 10104 <functionlink id="IsMethodSynthetic"></functionlink> 10105 </description> 10106 </capabilityfield> 10107 <capabilityfield id="can_get_owned_monitor_info"> 10108 <description> 10109 Can get information about ownership of monitors - 10110 <functionlink id="GetOwnedMonitorInfo"></functionlink> 10111 </description> 10112 </capabilityfield> 10113 <capabilityfield id="can_get_current_contended_monitor"> 10114 <description> 10115 Can <functionlink id="GetCurrentContendedMonitor"></functionlink> 10116 </description> 10117 </capabilityfield> 10118 <capabilityfield id="can_get_monitor_info"> 10119 <description> 10120 Can <functionlink id="GetObjectMonitorUsage"></functionlink> 10121 </description> 10122 </capabilityfield> 10123 <capabilityfield id="can_pop_frame"> 10124 <description> 10125 Can pop frames off the stack - <functionlink id="PopFrame"></functionlink> 10126 </description> 10127 </capabilityfield> 10128 <capabilityfield id="can_redefine_classes"> 10129 <description> 10130 Can redefine classes with <functionlink id="RedefineClasses"/>. 10131 </description> 10132 </capabilityfield> 10133 <capabilityfield id="can_signal_thread"> 10134 <description> 10135 Can send stop or interrupt to threads 10136 </description> 10137 </capabilityfield> 10138 <capabilityfield id="can_get_source_file_name"> 10139 <description> 10140 Can get the source file name of a class 10141 </description> 10142 </capabilityfield> 10143 <capabilityfield id="can_get_line_numbers"> 10144 <description> 10145 Can get the line number table of a method 10146 </description> 10147 </capabilityfield> 10148 <capabilityfield id="can_get_source_debug_extension"> 10149 <description> 10150 Can get the source debug extension of a class 10151 </description> 10152 </capabilityfield> 10153 <capabilityfield id="can_access_local_variables"> 10154 <description> 10155 Can set and get local variables 10156 </description> 10157 </capabilityfield> 10158 <capabilityfield id="can_maintain_original_method_order"> 10159 <description> 10160 Can return methods in the order they occur in the class file 10161 </description> 10162 </capabilityfield> 10163 <capabilityfield id="can_generate_single_step_events"> 10164 <description> 10165 Can get <eventlink id="SingleStep">single step</eventlink> events 10166 </description> 10167 </capabilityfield> 10168 <capabilityfield id="can_generate_exception_events"> 10169 <description> 10170 Can get <eventlink id="Exception">exception thrown</eventlink> and 10171 <eventlink id="ExceptionCatch">exception catch</eventlink> events 10172 </description> 10173 </capabilityfield> 10174 <capabilityfield id="can_generate_frame_pop_events"> 10175 <description> 10176 Can <functionlink id="NotifyFramePop">set</functionlink> and thus get 10177 <eventlink id="FramePop"></eventlink> events 10178 </description> 10179 </capabilityfield> 10180 <capabilityfield id="can_generate_breakpoint_events"> 10181 <description> 10182 Can <functionlink id="SetBreakpoint">set</functionlink> and thus get 10183 <eventlink id="Breakpoint"></eventlink> events 10184 </description> 10185 </capabilityfield> 10186 <capabilityfield id="can_suspend"> 10187 <description> 10188 Can suspend and resume threads 10189 </description> 10190 </capabilityfield> 10191 <capabilityfield id="can_redefine_any_class"> 10192 <description> 10193 Can modify (retransform or redefine) any modifiable class. 10194 See <functionlink id="IsModifiableClass"/>. 10195 </description> 10196 </capabilityfield> 10197 <capabilityfield id="can_get_current_thread_cpu_time"> 10198 <description> 10199 Can <functionlink id="GetCurrentThreadCpuTime">get</functionlink> 10200 current thread CPU time 10201 </description> 10202 </capabilityfield> 10203 <capabilityfield id="can_get_thread_cpu_time"> 10204 <description> 10205 Can <functionlink id="GetThreadCpuTime">get</functionlink> 10206 thread CPU time 10207 </description> 10208 </capabilityfield> 10209 <capabilityfield id="can_generate_method_entry_events" 10210 disp1="can_generate" disp2="_method_entry_events" 10211 > 10212 <description> 10213 Can generate method entry events on entering a method 10214 </description> 10215 </capabilityfield> 10216 <capabilityfield id="can_generate_method_exit_events" 10217 disp1="can_generate" disp2="_method_exit_events" 10218 > 10219 <description> 10220 Can generate method exit events on leaving a method 10221 </description> 10222 </capabilityfield> 10223 <capabilityfield id="can_generate_all_class_hook_events" 10224 disp1="can_generate" disp2="_all_class_hook_events" 10225 > 10226 <description> 10227 Can generate ClassFileLoadHook events for every loaded class. 10228 </description> 10229 </capabilityfield> 10230 <capabilityfield id="can_generate_compiled_method_load_events" 10231 disp1="can_generate" disp2="_compiled_method_load_events" 10232 > 10233 <description> 10234 Can generate events when a method is compiled or unloaded 10235 </description> 10236 </capabilityfield> 10237 <capabilityfield id="can_generate_monitor_events" 10238 disp1="can_generate" disp2="_monitor_events" 10239 > 10240 <description> 10241 Can generate events on monitor activity 10242 </description> 10243 </capabilityfield> 10244 <capabilityfield id="can_generate_vm_object_alloc_events" 10245 disp1="can_generate" disp2="_vm_object_alloc_events" 10246 > 10247 <description> 10248 Can generate events on VM allocation of an object 10249 </description> 10250 </capabilityfield> 10251 <capabilityfield id="can_generate_native_method_bind_events" 10252 disp1="can_generate" disp2="_native_method_bind_events" 10253 > 10254 <description> 10255 Can generate events when a native method is bound to its 10256 implementation 10257 </description> 10258 </capabilityfield> 10259 <capabilityfield id="can_generate_garbage_collection_events" 10260 disp1="can_generate" disp2="_garbage_collection_events" 10261 > 10262 <description> 10263 Can generate events when garbage collection begins or ends 10264 </description> 10265 </capabilityfield> 10266 <capabilityfield id="can_generate_object_free_events" 10267 disp1="can_generate" disp2="_object_free_events" 10268 > 10269 <description> 10270 Can generate events when the garbage collector frees an object 10271 </description> 10272 </capabilityfield> 10273 <capabilityfield id="can_force_early_return" since="1.1"> 10274 <description> 10275 Can return early from a method, as described in the 10276 <internallink id="ForceEarlyReturn">Force Early Return category</internallink>. 10277 </description> 10278 </capabilityfield> 10279 <capabilityfield id="can_get_owned_monitor_stack_depth_info" since="1.1"> 10280 <description> 10281 Can get information about owned monitors with stack depth - 10282 <functionlink id="GetOwnedMonitorStackDepthInfo"></functionlink> 10283 </description> 10284 </capabilityfield> 10285 <capabilityfield id="can_get_constant_pool" since="1.1"> 10286 <description> 10287 Can get the constant pool of a class - 10288 <functionlink id="GetConstantPool"></functionlink> 10289 </description> 10290 </capabilityfield> 10291 <capabilityfield id="can_set_native_method_prefix" since="1.1"> 10292 <description> 10293 Can set prefix to be applied when native method cannot be resolved - 10294 <functionlink id="SetNativeMethodPrefix"/> and 10295 <functionlink id="SetNativeMethodPrefixes"/> 10296 </description> 10297 </capabilityfield> 10298 <capabilityfield id="can_retransform_classes" since="1.1"> 10299 <description> 10300 Can retransform classes with <functionlink id="RetransformClasses"/>. 10301 In addition to the restrictions imposed by the specific 10302 implementation on this capability (see the 10303 <internallink id="capability">Capability</internallink> section), 10304 this capability must be set before the 10305 <eventlink id="ClassFileLoadHook"/> event is enabled for the 10306 first time in this environment. 10307 An environment that possesses this capability at the time that 10308 <code>ClassFileLoadHook</code> is enabled for the first time is 10309 said to be <i>retransformation capable</i>. 10310 An environment that does not possess this capability at the time that 10311 <code>ClassFileLoadHook</code> is enabled for the first time is 10312 said to be <i>retransformation incapable</i>. 10313 </description> 10314 </capabilityfield> 10315 <capabilityfield id="can_retransform_any_class" since="1.1"> 10316 <description> 10317 <functionlink id="RetransformClasses"/> can be called on any modifiable class. 10318 See <functionlink id="IsModifiableClass"/>. 10319 (<fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/> 10320 must also be set) 10321 </description> 10322 </capabilityfield> 10323 <capabilityfield id="can_generate_resource_exhaustion_heap_events" since="1.1"> 10324 <description> 10325 Can generate events when the VM is unable to allocate memory from 10326 the <tm>Java</tm> platform heap. 10327 See <eventlink id="ResourceExhausted"/>. 10328 </description> 10329 </capabilityfield> 10330 <capabilityfield id="can_generate_resource_exhaustion_threads_events" since="1.1"> 10331 <description> 10332 Can generate events when the VM is unable to create a thread. 10333 See <eventlink id="ResourceExhausted"/>. 10334 </description> 10335 </capabilityfield> 10336 <capabilityfield id="can_generate_early_vmstart" since="9"> 10337 <description> 10338 Can generate the <code>VMStart</code> event early. 10339 See <eventlink id="VMStart"/>. 10340 </description> 10341 </capabilityfield> 10342 <capabilityfield id="can_generate_early_class_hook_events" since="9"> 10343 <description> 10344 Can generate the <eventlink id="ClassFileLoadHook"/> events 10345 in the primordial phase. If this capability and 10346 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events"> 10347 <code>can_generate_all_class_hook_events</code></internallink> 10348 are enabled then the <eventlink id="ClassFileLoadHook"/> events 10349 can be posted for classes loaded in the primordial phase. 10350 See <eventlink id="ClassFileLoadHook"/>. 10351 </description> 10352 </capabilityfield> 10353 </capabilitiestypedef> 10354 10355 <function id="GetPotentialCapabilities" jkernel="yes" phase="onload" num="140"> 10356 <synopsis>Get Potential Capabilities</synopsis> 10357 <description> 10358 Returns via <paramlink id="capabilities_ptr"></paramlink> the <jvmti/> 10359 features that can potentially be possessed by this environment 10360 at this time. 10361 The returned capabilities differ from the complete set of capabilities 10362 implemented by the VM in two cases: another environment possesses 10363 capabilities that can only be possessed by one environment, or the 10364 current <functionlink id="GetPhase">phase</functionlink> is live, 10365 and certain capabilities can only be added during the <code>OnLoad</code> phase. 10366 The <functionlink id="AddCapabilities"></functionlink> function 10367 may be used to set any or all or these capabilities. 10368 Currently possessed capabilities are included. 10369 <p/> 10370 Typically this function is used in the <code>OnLoad</code> function. 10371 Some virtual machines may allow a limited set of capabilities to be 10372 added in the live phase. 10373 In this case, the set of potentially available capabilities 10374 will likely differ from the <code>OnLoad</code> phase set. 10375 <p/> 10376 See the 10377 <internallink id="capabilityExamples">Capability Examples</internallink>. 10378 </description> 10379 <origin>new</origin> 10380 <capabilities> 10381 </capabilities> 10382 <parameters> 10383 <param id="capabilities_ptr"> 10384 <outptr><struct>jvmtiCapabilities</struct></outptr> 10385 <description> 10386 On return, points to the <jvmti/> capabilities that may be added. 10387 </description> 10388 </param> 10389 </parameters> 10390 <errors> 10391 </errors> 10392 </function> 10393 10394 <elide> 10395 <function id="EstimateCostOfCapabilities" phase="onload" num="141"> 10396 <synopsis>Estimate Cost Of Capabilities</synopsis> 10397 <description> 10398 <issue>There is strong opposition to this function. The concern is 10399 that it would be difficult or impossible to provide meaningful 10400 numbers, as the amount of impact is conditional on many factors 10401 that a single number could not represent. There is doubt that 10402 conditional implementations would be used or are even a good idea. 10403 The thought is that release documentation for the implementation 10404 would be the best means of exposing this information. 10405 Unless new arguments are presented, I intend to remove this 10406 function in the next revision. 10407 </issue> 10408 <p/> 10409 Return via the <paramlink id="time_impact_ptr"></paramlink> and 10410 <paramlink id="space_impact_ptr"></paramlink> an estimate of the impact 10411 of adding the capabilities pointed to by 10412 <paramlink id="capabilities_ptr"></paramlink>. 10413 The returned estimates are in percentage of additional overhead, thus 10414 a time impact of 100 mean the application might run 10415 at half the speed. 10416 The estimates are very rough approximations and are not guaranteed. 10417 Note also, that the estimates are of the impact of having the 10418 capability available--when and if it is used the impact may be 10419 much greater. 10420 Estimates can be for a single capability or for a set of 10421 capabilities. Note that the costs are not necessarily additive, 10422 adding support for one capability might make another available 10423 for free or conversely having two capabilities at once may 10424 have multiplicative impact. 10425 Estimates are relative to the current set of capabilities - 10426 that is, how much more impact given the currently possessed capabilities. 10427 <p/> 10428 Typically this function is used in the OnLoad function, 10429 some virtual machines may allow a limited set of capabilities to be 10430 added in the live phase. 10431 In this case, the set of potentially available capabilities 10432 will likely differ from the OnLoad phase set. 10433 <p/> 10434 See the 10435 <internallink id="capabilityExamples">Capability Examples</internallink>. 10436 </description> 10437 <origin>new</origin> 10438 <capabilities> 10439 </capabilities> 10440 <parameters> 10441 <param id="capabilities_ptr"> 10442 <inptr><struct>jvmtiCapabilities</struct></inptr> 10443 <description> 10444 points to the <jvmti/> capabilities to evaluate. 10445 </description> 10446 </param> 10447 <param id="time_impact_ptr"> 10448 <outptr><jint/></outptr> 10449 <description> 10450 On return, points to the estimated percentage increase in 10451 run time if this capability was added. 10452 </description> 10453 </param> 10454 <param id="space_impact_ptr"> 10455 <outptr><jint/></outptr> 10456 <description> 10457 On return, points to the estimated percentage increase in 10458 memory space used if this capability was added. 10459 </description> 10460 </param> 10461 </parameters> 10462 <errors> 10463 <error id="JVMTI_ERROR_NOT_AVAILABLE"> 10464 The desired capabilities are not even potentially available. 10465 </error> 10466 </errors> 10467 </function> 10468 </elide> 10469 10470 <function id="AddCapabilities" jkernel="yes" phase="onload" num="142"> 10471 <synopsis>Add Capabilities</synopsis> 10472 <description> 10473 Set new capabilities by adding the capabilities 10474 whose values are set to one (<code>1</code>) in 10475 <code>*</code><paramlink id="capabilities_ptr"></paramlink>. 10476 All previous capabilities are retained. 10477 Typically this function is used in the <code>OnLoad</code> function. 10478 Some virtual machines may allow a limited set of capabilities to be 10479 added in the live phase. 10480 <p/> 10481 See the 10482 <internallink id="capabilityExamples">Capability Examples</internallink>. 10483 </description> 10484 <origin>new</origin> 10485 <capabilities> 10486 </capabilities> 10487 <parameters> 10488 <param id="capabilities_ptr"> 10489 <inptr><struct>jvmtiCapabilities</struct></inptr> 10490 <description> 10491 Points to the <jvmti/> capabilities to add. 10492 </description> 10493 </param> 10494 </parameters> 10495 <errors> 10496 <error id="JVMTI_ERROR_NOT_AVAILABLE"> 10497 The desired capabilities are not even potentially available. 10498 </error> 10499 </errors> 10500 </function> 10501 10502 10503 <function id="RelinquishCapabilities" phase="onload" num="143"> 10504 <synopsis>Relinquish Capabilities</synopsis> 10505 <description> 10506 Relinquish the capabilities 10507 whose values are set to one (<code>1</code>) in 10508 <code>*</code><paramlink id="capabilities_ptr"></paramlink>. 10509 Some implementations may allow only one environment to have a capability 10510 (see the <internallink id="capability">capability introduction</internallink>). 10511 This function releases capabilities 10512 so that they may be used by other agents. 10513 All other capabilities are retained. 10514 The capability will no longer be present in <functionlink id="GetCapabilities"></functionlink>. 10515 Attempting to relinquish a capability that the agent does not possess is not an error. 10516 <issue> 10517 It is possible for the agent to be actively using capabilities 10518 which are being relinquished. For example, a thread is currently 10519 suspended and can_suspend is being relinquished or an event is currently 10520 enabled and can_generate_whatever is being relinquished. 10521 There are three possible ways we could spec this: 10522 <ul> 10523 <li>relinquish automatically releases them</li> 10524 <li>relinquish checks and returns some error code if held</li> 10525 <li>it is the agent's responsibility and it is not checked</li> 10526 </ul> 10527 One of these should be chosen. 10528 </issue> 10529 </description> 10530 <origin>new</origin> 10531 <capabilities> 10532 </capabilities> 10533 <parameters> 10534 <param id="capabilities_ptr"> 10535 <inptr><struct>jvmtiCapabilities</struct></inptr> 10536 <description> 10537 Points to the <jvmti/> capabilities to relinquish. 10538 </description> 10539 </param> 10540 </parameters> 10541 <errors> 10542 </errors> 10543 </function> 10544 10545 10546 10547 <function id="GetCapabilities" jkernel="yes" phase="any" num="89"> 10548 <synopsis>Get Capabilities</synopsis> 10549 <description> 10550 Returns via <paramlink id="capabilities_ptr"></paramlink> the optional <jvmti/> 10551 features which this environment currently possesses. 10552 Each possessed capability is indicated by a one (<code>1</code>) in the 10553 corresponding field of the <internallink id="jvmtiCapabilities">capabilities 10554 structure</internallink>. 10555 An environment does not possess a capability unless it has been successfully added with 10556 <functionlink id="AddCapabilities"/>. 10557 An environment only loses possession of a capability if it has been relinquished with 10558 <functionlink id="RelinquishCapabilities"/>. Thus, this function returns the net result 10559 of the <code>AddCapabilities</code> and <code>RelinquishCapabilities</code> calls which 10560 have been made. 10561 <p/> 10562 See the 10563 <internallink id="capabilityExamples">Capability Examples</internallink>. 10564 </description> 10565 <origin>jvmdiClone</origin> 10566 <capabilities> 10567 </capabilities> 10568 <parameters> 10569 <param id="capabilities_ptr"> 10570 <outptr><struct>jvmtiCapabilities</struct></outptr> 10571 <description> 10572 On return, points to the <jvmti/> capabilities. 10573 </description> 10574 </param> 10575 </parameters> 10576 <errors> 10577 </errors> 10578 </function> 10579 10580 </category> 10581 10582 10583 <category id="timers" label="Timers"> 10584 10585 <intro> 10586 These functions provide timing information. 10587 The resolution at which the time is updated is not specified. 10588 They provides nanosecond precision, but not necessarily nanosecond accuracy. 10589 Details about the timers, such as their maximum values, can be accessed with 10590 the timer information functions. 10591 </intro> 10592 10593 <typedef id="jvmtiTimerInfo" label="Timer Info"> 10594 <description> 10595 The information function for each timer returns this data structure. 10596 </description> 10597 <field id="max_value"> 10598 <jlong/> 10599 <description> 10600 The maximum value the timer can reach. 10601 After this value is reached the timer wraps back to zero. 10602 This is an unsigned value. If tested or printed as a jlong (signed value) 10603 it may appear to be a negative number. 10604 </description> 10605 </field> 10606 <field id="may_skip_forward"> 10607 <jboolean/> 10608 <description> 10609 If true, the timer can be externally adjusted and as a result skip forward. 10610 If false, the timer value will never increase faster than real time. 10611 </description> 10612 </field> 10613 <field id="may_skip_backward"> 10614 <jboolean/> 10615 <description> 10616 If true, the timer can be externally adjusted and as a result skip backward. 10617 If false, the timer value will be monotonically increasing. 10618 </description> 10619 </field> 10620 <field id="kind"> 10621 <enum>jvmtiTimerKind</enum> 10622 <description> 10623 The kind of timer. 10624 On a platform that does not distinguish between user and system time, <datalink 10625 id="JVMTI_TIMER_TOTAL_CPU"><code>JVMTI_TIMER_TOTAL_CPU</code></datalink> 10626 is returned. 10627 </description> 10628 </field> 10629 <field id="reserved1"> 10630 <jlong/> 10631 <description> 10632 Reserved for future use. 10633 </description> 10634 </field> 10635 <field id="reserved2"> 10636 <jlong/> 10637 <description> 10638 Reserved for future use. 10639 </description> 10640 </field> 10641 </typedef> 10642 10643 <intro> 10644 Where the timer kind is -- 10645 10646 <constants id="jvmtiTimerKind" label="Timer Kinds" kind="enum"> 10647 <constant id="JVMTI_TIMER_USER_CPU" num="30"> 10648 CPU time that a thread is in user mode. 10649 </constant> 10650 <constant id="JVMTI_TIMER_TOTAL_CPU" num="31"> 10651 CPU time that a thread is in user or system mode. 10652 </constant> 10653 <constant id="JVMTI_TIMER_ELAPSED" num="32"> 10654 Elapsed time. 10655 </constant> 10656 </constants> 10657 </intro> 10658 10659 <function id="GetCurrentThreadCpuTimerInfo" callbacksafe="safe" impl="innative notrace" phase="start" num="134"> 10660 <synopsis>Get Current Thread CPU Timer Information</synopsis> 10661 <description> 10662 Get information about the 10663 <functionlink id="GetCurrentThreadCpuTime"/> timer. 10664 The fields of the <datalink id="jvmtiTimerInfo"/> structure 10665 are filled in with details about the timer. 10666 This information is specific to the platform and the implementation of 10667 <functionlink id="GetCurrentThreadCpuTime"/> and thus 10668 does not vary by thread nor does it vary 10669 during a particular invocation of the VM. 10670 <p/> 10671 Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/> 10672 and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values 10673 returned by <code>GetCurrentThreadCpuTimerInfo</code> 10674 and <functionlink id="GetThreadCpuTimerInfo"/> 10675 may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information. 10676 </description> 10677 <origin>new</origin> 10678 <capabilities> 10679 <required id="can_get_current_thread_cpu_time"> 10680 Can get current thread CPU time. 10681 </required> 10682 </capabilities> 10683 <parameters> 10684 <param id="info_ptr"> 10685 <outptr><struct>jvmtiTimerInfo</struct></outptr> 10686 <description> 10687 On return, filled with information describing the time 10688 returned by <functionlink id="GetCurrentThreadCpuTime"/>. 10689 </description> 10690 </param> 10691 </parameters> 10692 <errors> 10693 </errors> 10694 </function> 10695 10696 <function id="GetCurrentThreadCpuTime" callbacksafe="safe" impl="innative notrace" phase="start" num="135"> 10697 <synopsis>Get Current Thread CPU Time</synopsis> 10698 <description> 10699 Return the CPU time utilized by the current thread. 10700 <p/> 10701 Note that the <functionlink id="GetThreadCpuTime"/> 10702 function provides CPU time for any thread, including 10703 the current thread. <code>GetCurrentThreadCpuTime</code> 10704 exists to support platforms which cannot 10705 supply CPU time for threads other than the current 10706 thread or which have more accurate information for 10707 the current thread (see 10708 <functionlink id="GetCurrentThreadCpuTimerInfo"/> vs 10709 <functionlink id="GetThreadCpuTimerInfo"/>). 10710 On many platforms this call will be equivalent to: 10711<example> 10712 GetThreadCpuTime(env, NULL, nanos_ptr) 10713</example> 10714 </description> 10715 <origin>new</origin> 10716 <capabilities> 10717 <required id="can_get_current_thread_cpu_time"> 10718 Can get current thread CPU time. 10719 <p/> 10720 If this capability is enabled after threads have started, 10721 the implementation may choose any time up 10722 to and including the time that the capability is enabled 10723 as the point where CPU time collection starts. 10724 <p/> 10725 This capability must be potentially available on any 10726 platform where 10727 <internallink id="jvmtiCapabilities.can_get_thread_cpu_time"><code>can_get_thread_cpu_time</code></internallink> 10728 is potentially available. 10729 </required> 10730 </capabilities> 10731 <parameters> 10732 <param id="nanos_ptr"> 10733 <outptr><jlong/></outptr> 10734 <description> 10735 On return, points to the CPU time used by this thread 10736 in nanoseconds. 10737 This is an unsigned value. If tested or printed as a jlong (signed value) 10738 it may appear to be a negative number. 10739 </description> 10740 </param> 10741 </parameters> 10742 <errors> 10743 </errors> 10744 </function> 10745 10746 <function id="GetThreadCpuTimerInfo" num="136"> 10747 <synopsis>Get Thread CPU Timer Information</synopsis> 10748 <description> 10749 Get information about the 10750 <functionlink id="GetThreadCpuTime"/> timer. 10751 The fields of the <datalink id="jvmtiTimerInfo"/> structure 10752 are filled in with details about the timer. 10753 This information is specific to the platform and the implementation of 10754 <functionlink id="GetThreadCpuTime"/> and thus 10755 does not vary by thread nor does it vary 10756 during a particular invocation of the VM. 10757 <p/> 10758 Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/> 10759 and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values 10760 returned by <functionlink id="GetCurrentThreadCpuTimerInfo"/> 10761 and <code>GetThreadCpuTimerInfo</code> 10762 may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information. 10763 </description> 10764 <origin>new</origin> 10765 <capabilities> 10766 <required id="can_get_thread_cpu_time"> 10767 Can get thread CPU time. 10768 </required> 10769 </capabilities> 10770 <parameters> 10771 <param id="info_ptr"> 10772 <outptr><struct>jvmtiTimerInfo</struct></outptr> 10773 <description> 10774 On return, filled with information describing the time 10775 returned by <functionlink id="GetThreadCpuTime"/>. 10776 </description> 10777 </param> 10778 </parameters> 10779 <errors> 10780 </errors> 10781 </function> 10782 10783 <function id="GetThreadCpuTime" num="137"> 10784 <synopsis>Get Thread CPU Time</synopsis> 10785 <description> 10786 Return the CPU time utilized by the specified thread. 10787 <p/> 10788 Get information about this timer with 10789 <functionlink id="GetThreadCpuTimerInfo"/>. 10790 </description> 10791 <origin>new</origin> 10792 <capabilities> 10793 <required id="can_get_thread_cpu_time"> 10794 Can get thread CPU time. 10795 <p/> 10796 If this capability is enabled after threads have started, 10797 the implementation may choose any time up 10798 to and including the time that the capability is enabled 10799 as the point where CPU time collection starts. 10800 </required> 10801 </capabilities> 10802 <parameters> 10803 <param id="thread"> 10804 <jthread null="current"/> 10805 <description> 10806 The thread to query. 10807 </description> 10808 </param> 10809 <param id="nanos_ptr"> 10810 <outptr><jlong/></outptr> 10811 <description> 10812 On return, points to the CPU time used by the specified thread 10813 in nanoseconds. 10814 This is an unsigned value. If tested or printed as a jlong (signed value) 10815 it may appear to be a negative number. 10816 </description> 10817 </param> 10818 </parameters> 10819 <errors> 10820 </errors> 10821 </function> 10822 10823 <function id="GetTimerInfo" phase="any" callbacksafe="safe" num="138"> 10824 <synopsis>Get Timer Information</synopsis> 10825 <description> 10826 Get information about the 10827 <functionlink id="GetTime"/> timer. 10828 The fields of the <datalink id="jvmtiTimerInfo"/> structure 10829 are filled in with details about the timer. 10830 This information will not change during a particular invocation of the VM. 10831 </description> 10832 <origin>new</origin> 10833 <capabilities> 10834 </capabilities> 10835 <parameters> 10836 <param id="info_ptr"> 10837 <outptr><struct>jvmtiTimerInfo</struct></outptr> 10838 <description> 10839 On return, filled with information describing the time 10840 returned by <functionlink id="GetTime"/>. 10841 </description> 10842 </param> 10843 </parameters> 10844 <errors> 10845 </errors> 10846 </function> 10847 10848 <function id="GetTime" phase="any" callbacksafe="safe" num="139"> 10849 <synopsis>Get Time</synopsis> 10850 <description> 10851 Return the current value of the system timer, in nanoseconds. 10852 <p/> 10853 The value returned represents nanoseconds since some fixed but 10854 arbitrary time (perhaps in the future, so values may be 10855 negative). This function provides nanosecond precision, but not 10856 necessarily nanosecond accuracy. No guarantees are made about 10857 how frequently values change. 10858 <p/> 10859 Get information about this timer with 10860 <functionlink id="GetTimerInfo"/>. 10861 </description> 10862 <origin>new</origin> 10863 <capabilities> 10864 </capabilities> 10865 <parameters> 10866 <param id="nanos_ptr"> 10867 <outptr><jlong/></outptr> 10868 <description> 10869 On return, points to the time in nanoseconds. 10870 This is an unsigned value. If tested or printed as a jlong (signed value) 10871 it may appear to be a negative number. 10872 </description> 10873 </param> 10874 </parameters> 10875 <errors> 10876 </errors> 10877 </function> 10878 10879 <function id="GetAvailableProcessors" phase="any" num="144"> 10880 <synopsis>Get Available Processors</synopsis> 10881 <description> 10882 Returns the number of processors available to the Java virtual machine. 10883 <p/> 10884 This value may change during a particular invocation of the virtual machine. 10885 Applications that are sensitive to the number of available processors should 10886 therefore occasionally poll this property. 10887 </description> 10888 <origin>new</origin> 10889 <capabilities> 10890 </capabilities> 10891 <parameters> 10892 <param id="processor_count_ptr"> 10893 <outptr><jint/></outptr> 10894 <description> 10895 On return, points to the maximum number of processors available to the 10896 virtual machine; never smaller than one. 10897 </description> 10898 </param> 10899 </parameters> 10900 <errors> 10901 </errors> 10902 </function> 10903 10904 </category> 10905 10906 10907 <category id="classLoaderSearch" label="Class Loader Search"> 10908 10909 <intro> 10910 These functions allow the agent to add to the locations that a class loader searches for a class. 10911 This is useful for installing instrumentation under the correct class loader. 10912 </intro> 10913 10914 <function id="AddToBootstrapClassLoaderSearch" jkernel="yes" phase="onload" num="149"> 10915 <synopsis>Add To Bootstrap Class Loader Search</synopsis> 10916 <description> 10917 This function can be used to cause instrumentation classes to be defined by the 10918 bootstrap class loader. See <vmspec chapter="5.3.1"/>. 10919 After the bootstrap 10920 class loader unsuccessfully searches for a class, the specified platform-dependent 10921 search path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in 10922 the <paramlink id="segment"/>. This function may be called multiple times to add multiple segments, 10923 the segments will be searched in the order that this function was called. 10924 <p/> 10925 In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent 10926 search path segment to be searched after the bootstrap class loader unsuccessfully searches 10927 for a class. The segment is typically a directory or JAR file. 10928 <p/> 10929 In the live phase the <paramlink id="segment"/> may be used to specify any platform-dependent 10930 path to a <externallink id="docs/technotes/guides/jar/jar.html"> 10931 JAR file</externallink>. The agent should take care that the JAR file does not 10932 contain any classes or resources other than those to be defined by the bootstrap 10933 class loader for the purposes of instrumentation. 10934 <p/> 10935 <vmspec/> specifies that a subsequent attempt to resolve a symbolic 10936 reference that the Java virtual machine has previously unsuccessfully attempted 10937 to resolve always fails with the same error that was thrown as a result of the 10938 initial resolution attempt. Consequently, if the JAR file contains an entry 10939 that corresponds to a class for which the Java virtual machine has 10940 unsuccessfully attempted to resolve a reference, then subsequent attempts to 10941 resolve that reference will fail with the same error as the initial attempt. 10942 </description> 10943 <origin>new</origin> 10944 <capabilities> 10945 </capabilities> 10946 <parameters> 10947 <param id="segment"> 10948 <inbuf><char/></inbuf> 10949 <description> 10950 The platform-dependent search path segment, encoded as a 10951 <internallink id="mUTF">modified UTF-8</internallink> string. 10952 </description> 10953 </param> 10954 </parameters> 10955 <errors> 10956 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 10957 <paramlink id="segment"/> is an invalid path. In the live phase, anything other than an 10958 existing JAR file is an invalid path. 10959 </error> 10960 </errors> 10961 </function> 10962 10963 <function id="AddToSystemClassLoaderSearch" jkernel="yes" phase="onload" num="151" since="1.1"> 10964 <synopsis>Add To System Class Loader Search</synopsis> 10965 <description> 10966 This function can be used to cause instrumentation classes to be 10967 defined by the system class loader. See <vmspec chapter="5.3.2"/>. 10968 After the class loader unsuccessfully searches for a class, the specified platform-dependent search 10969 path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in the 10970 <paramlink id="segment"/>. This function may be called multiple times to add multiple segments, the 10971 segments will be searched in the order that this function was called. 10972 <p/> 10973 In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent 10974 search path segment to be searched after the system class loader unsuccessfully searches 10975 for a class. The segment is typically a directory or JAR file. 10976 <p/> 10977 In the live phase the <paramlink id="segment"/> is a platform-dependent path to a 10978 <externallink id="docs/technotes/guides/jar/jar.html">JAR file</externallink> to be 10979 searched after the system class loader unsuccessfully searches for a class. The agent should 10980 take care that the JAR file does not contain any classes or resources other than those to be 10981 defined by the system class loader for the purposes of instrumentation. 10982 <p/> 10983 In the live phase the system class loader supports adding a JAR file to be searched if 10984 the system class loader implements a method name <code>appendToClassPathForInstrumentation</code> 10985 which takes a single parameter of type <code>java.lang.String</code>. The method is not required 10986 to have <code>public</code> access. 10987 <p/> 10988 <vmspec/> specifies that a subsequent attempt to resolve a symbolic 10989 reference that the Java virtual machine has previously unsuccessfully attempted 10990 to resolve always fails with the same error that was thrown as a result of the 10991 initial resolution attempt. Consequently, if the JAR file contains an entry 10992 that corresponds to a class for which the Java virtual machine has 10993 unsuccessfully attempted to resolve a reference, then subsequent attempts to 10994 resolve that reference will fail with the same error as the initial attempt. 10995 </description> 10996 <origin>new</origin> 10997 <capabilities> 10998 </capabilities> 10999 <parameters> 11000 <param id="segment"> 11001 <inbuf><char/></inbuf> 11002 <description> 11003 The platform-dependent search path segment, encoded as a 11004 <internallink id="mUTF">modified UTF-8</internallink> string. 11005 </description> 11006 </param> 11007 </parameters> 11008 <errors> 11009 <error id="JVMTI_ERROR_ILLEGAL_ARGUMENT"> 11010 <paramlink id="segment"/> is an invalid path. In the live phase, anything other than an 11011 existing JAR file is an invalid path. 11012 </error> 11013 <error id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED"> 11014 Operation not supported by the system class loader. 11015 </error> 11016 </errors> 11017 </function> 11018 11019 </category> 11020 11021 11022 <category id="props" label="System Properties"> 11023 11024 <intro> 11025 These functions get and set system properties. 11026 </intro> 11027 11028 <function id="GetSystemProperties" phase="onload" num="130"> 11029 <synopsis>Get System Properties</synopsis> 11030 <description> 11031 The list of VM system property keys which may be used with 11032 <functionlink id="GetSystemProperty"/> is returned. 11033 It is strongly recommended that virtual machines provide the 11034 following property keys: 11035 <ul> 11036 <li><code>java.vm.vendor</code></li> 11037 <li><code>java.vm.version</code></li> 11038 <li><code>java.vm.name</code></li> 11039 <li><code>java.vm.info</code></li> 11040 <li><code>java.library.path</code></li> 11041 <li><code>java.class.path</code></li> 11042 </ul> 11043 Provides access to system properties defined by and used 11044 by the VM. 11045 Properties set on the command-line are included. 11046 This allows getting and setting of these properties 11047 before the VM even begins executing bytecodes. 11048 Since this is a VM view of system properties, the set of available 11049 properties will usually be different than that 11050 in <code>java.lang.System.getProperties</code>. 11051 JNI method invocation may be used to access 11052 <code>java.lang.System.getProperties</code>. 11053 <p/> 11054 The set of properties may grow during execution. 11055 </description> 11056 <origin>new</origin> 11057 <capabilities> 11058 </capabilities> 11059 <parameters> 11060 <param id="count_ptr"> 11061 <outptr><jint/></outptr> 11062 <description> 11063 On return, points to the number of property keys returned. 11064 </description> 11065 </param> 11066 <param id="property_ptr"> 11067 <allocallocbuf outcount="count_ptr"><char/></allocallocbuf> 11068 <description> 11069 On return, points to an array of property keys, encoded as 11070 <internallink id="mUTF">modified UTF-8</internallink> strings. 11071 </description> 11072 </param> 11073 </parameters> 11074 <errors> 11075 </errors> 11076 </function> 11077 11078 <function id="GetSystemProperty" phase="onload" num="131"> 11079 <synopsis>Get System Property</synopsis> 11080 <description> 11081 Return a VM system property value given the property key. 11082 <p/> 11083 The function <functionlink id="GetSystemProperties"/> 11084 returns the set of property keys which may be used. 11085 The properties which can be retrieved may grow during 11086 execution. 11087 <p/> 11088 Since this is a VM view of system properties, the values 11089 of properties may differ from that returned by 11090 <code>java.lang.System.getProperty(String)</code>. 11091 A typical VM might copy the values of the VM system 11092 properties into the <code>Properties</code> held by 11093 <code>java.lang.System</code> during the initialization 11094 of that class. Thereafter any changes to the VM system 11095 properties (with <functionlink id="SetSystemProperty"/>) 11096 or the <code>java.lang.System</code> system properties 11097 (with <code>java.lang.System.setProperty(String,String)</code>) 11098 would cause the values to diverge. 11099 JNI method invocation may be used to access 11100 <code>java.lang.System.getProperty(String)</code>. 11101 </description> 11102 <origin>new</origin> 11103 <capabilities> 11104 </capabilities> 11105 <parameters> 11106 <param id="property"> 11107 <inbuf><char/></inbuf> 11108 <description> 11109 The key of the property to retrieve, encoded as a 11110 <internallink id="mUTF">modified UTF-8</internallink> string. 11111 </description> 11112 </param> 11113 <param id="value_ptr"> 11114 <allocbuf><char/></allocbuf> 11115 <description> 11116 On return, points to the property value, encoded as a 11117 <internallink id="mUTF">modified UTF-8</internallink> string. 11118 </description> 11119 </param> 11120 </parameters> 11121 <errors> 11122 <error id="JVMTI_ERROR_NOT_AVAILABLE"> 11123 This property is not available. 11124 Use <functionlink id="GetSystemProperties"/> to find available properties. 11125 </error> 11126 </errors> 11127 </function> 11128 11129 <function id="SetSystemProperty" phase="onloadOnly" num="132"> 11130 <synopsis>Set System Property</synopsis> 11131 <description> 11132 Set a VM system property value. 11133 <p/> 11134 The function <functionlink id="GetSystemProperties"/> 11135 returns the set of property keys, some of these may be settable. 11136 See <functionlink id="GetSystemProperty"/>. 11137 </description> 11138 <origin>new</origin> 11139 <capabilities> 11140 </capabilities> 11141 <parameters> 11142 <param id="property"> 11143 <inbuf><char/></inbuf> 11144 <description> 11145 The key of the property, encoded as a 11146 <internallink id="mUTF">modified UTF-8</internallink> string. 11147 </description> 11148 </param> 11149 <param id="value_ptr"> 11150 <inbuf> 11151 <char/> 11152 <nullok> 11153 do not set the value, but return <errorlink id="JVMTI_ERROR_NOT_AVAILABLE"/> 11154 if the property is not writeable 11155 </nullok> 11156 </inbuf> 11157 <description> 11158 The property value to set, encoded as a 11159 <internallink id="mUTF">modified UTF-8</internallink> string. 11160 </description> 11161 </param> 11162 </parameters> 11163 <errors> 11164 <error id="JVMTI_ERROR_NOT_AVAILABLE"> 11165 This property is not available or is not writeable. 11166 </error> 11167 </errors> 11168 </function> 11169 11170 </category> 11171 11172 <category id="general" label="General"> 11173 11174 <intro> 11175 </intro> 11176 11177 <function id="GetPhase" jkernel="yes" phase="any" num="133"> 11178 <synopsis>Get Phase</synopsis> 11179 <description> 11180 Return the current phase of VM execution. 11181 The phases proceed in sequence: 11182 <constants id="jvmtiPhase" label="Phases of execution" kind="enum"> 11183 <constant id="JVMTI_PHASE_ONLOAD" num="1"> 11184 <code>OnLoad</code> phase: while in the 11185 <internallink id="onload"><code>Agent_OnLoad</code></internallink> 11186 or, for statically linked agents, the <internallink id="onload"> 11187 <code>Agent_OnLoad_<agent-lib-name> 11188 </code></internallink> function. 11189 </constant> 11190 <constant id="JVMTI_PHASE_PRIMORDIAL" num="2"> 11191 Primordial phase: between return from <code>Agent_OnLoad</code> 11192 or <code>Agent_OnLoad_<agent-lib-name></code> and the 11193 <code>VMStart</code> event. 11194 </constant> 11195 <constant id="JVMTI_PHASE_START" num="6"> 11196 Start phase: when the <eventlink id="VMStart"><code>VMStart</code></eventlink> event 11197 is sent and until the <code>VMInit</code> event is sent. 11198 </constant> 11199 <constant id="JVMTI_PHASE_LIVE" num="4"> 11200 Live phase: when the <eventlink id="VMInit"><code>VMInit</code></eventlink> event is sent 11201 and until the <eventlink id="VMDeath"></eventlink> event returns. 11202 </constant> 11203 <constant id="JVMTI_PHASE_DEAD" num="8"> 11204 Dead phase: after the <eventlink id="VMDeath"></eventlink> event returns or after 11205 start-up failure. 11206 </constant> 11207 </constants> 11208 In the case of start-up failure the VM will proceed directly to the dead 11209 phase skipping intermediate phases and neither a <code>VMInit</code> nor 11210 <code>VMDeath</code> event will be sent. 11211 <p/> 11212 Most <jvmti/> functions operate only in the live phase. 11213 The following functions operate in either the <code>OnLoad</code> or live phases: 11214 <functionphaselist phase="onload"/> 11215 The following functions operate in only the <code>OnLoad</code> phase: 11216 <functionphaselist phase="onloadOnly"/> 11217 The following functions operate in the start or live phases: 11218 <functionphaselist phase="start"/> 11219 The following functions operate in any phase: 11220 <functionphaselist phase="any"/> 11221 JNI functions (except the Invocation API) must only be used in the start or live phases. 11222 <p/> 11223 Most <jvmti/> events are sent only in the live phase. 11224 The following events operate in others phases: 11225 <eventphaselist phase="start"/> 11226 <eventphaselist phase="any"/> 11227 </description> 11228 <origin>new</origin> 11229 <capabilities> 11230 </capabilities> 11231 <parameters> 11232 <param id="phase_ptr"> 11233 <outptr><enum>jvmtiPhase</enum></outptr> 11234 <description> 11235 On return, points to the phase. 11236 </description> 11237 </param> 11238 </parameters> 11239 <errors> 11240 </errors> 11241 </function> 11242 11243 <function id="DisposeEnvironment" jkernel="yes" phase="any" num="127"> 11244 <synopsis>Dispose Environment</synopsis> 11245 <description> 11246 Shutdown a <jvmti/> connection created with JNI <code>GetEnv</code> 11247 (see <internallink id="environments"><jvmti/> Environments</internallink>). 11248 Dispose of any resources held by the environment. 11249 <issue> 11250 What resources are reclaimed? What is undone? 11251 Breakpoints,watchpoints removed? 11252 </issue> 11253 Threads suspended by this environment are not resumed by this call, 11254 this must be done explicitly by the agent. 11255 Memory allocated by this environment via calls to <jvmti/> functions 11256 is not released, this can be done explicitly by the agent 11257 by calling <functionlink id="Deallocate"/>. 11258 Raw monitors created by this environment are not destroyed, 11259 this can be done explicitly by the agent 11260 by calling <functionlink id="DestroyRawMonitor"/>. 11261 The state of threads waiting on raw monitors created by this environment 11262 are not affected. 11263 <p/> 11264 Any <functionlink id="SetNativeMethodPrefix">native method 11265 prefixes</functionlink> for this environment will be unset; 11266 the agent must remove any prefixed native methods before 11267 dispose is called. 11268 <p/> 11269 Any <internallink id="capability">capabilities</internallink> 11270 held by this environment are relinquished. 11271 <p/> 11272 Events enabled by this environment will no longer be sent, however 11273 event handlers currently running will continue to run. Caution must 11274 be exercised in the design of event handlers whose environment may 11275 be disposed and thus become invalid during their execution. 11276 <p/> 11277 This environment may not be used after this call. 11278 This call returns to the caller. 11279 </description> 11280 <origin>new</origin> 11281 <capabilities> 11282 </capabilities> 11283 <parameters> 11284 </parameters> 11285 <errors> 11286 </errors> 11287 </function> 11288 11289 <function id="SetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="148"> 11290 <synopsis>Set Environment Local Storage</synopsis> 11291 <description> 11292 The VM stores a pointer value associated with each environment. 11293 This pointer value is called <i>environment-local storage</i>. 11294 This value is <code>NULL</code> unless set with this function. 11295 Agents can allocate memory in which they store environment specific 11296 information. By setting environment-local storage it can then be 11297 accessed with 11298 <functionlink id="GetEnvironmentLocalStorage"></functionlink>. 11299 <p/> 11300 Called by the agent to set the value of the <jvmti/> 11301 environment-local storage. <jvmti/> supplies to the agent a pointer-size 11302 environment-local storage that can be used to record per-environment 11303 information. 11304 </description> 11305 <origin>new</origin> 11306 <capabilities> 11307 </capabilities> 11308 <parameters> 11309 <param id="data"> 11310 <inbuf> 11311 <void/> 11312 <nullok>value is set to <code>NULL</code></nullok> 11313 </inbuf> 11314 <description> 11315 The value to be entered into the environment-local storage. 11316 </description> 11317 </param> 11318 </parameters> 11319 <errors> 11320 </errors> 11321 </function> 11322 11323 <function id="GetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="147"> 11324 <synopsis>Get Environment Local Storage</synopsis> 11325 <description> 11326 Called by the agent to get the value of the <jvmti/> environment-local 11327 storage. 11328 </description> 11329 <origin>new</origin> 11330 <capabilities> 11331 </capabilities> 11332 <parameters> 11333 <param id="data_ptr"> 11334 <agentbuf><void/></agentbuf> 11335 <description> 11336 Pointer through which the value of the environment local 11337 storage is returned. 11338 If environment-local storage has not been set with 11339 <functionlink id="SetEnvironmentLocalStorage"></functionlink> returned 11340 pointer is <code>NULL</code>. 11341 </description> 11342 </param> 11343 </parameters> 11344 <errors> 11345 </errors> 11346 </function> 11347 11348 <function id="GetVersionNumber" jkernel="yes" phase="any" num="88"> 11349 <synopsis>Get Version Number</synopsis> 11350 <description> 11351 Return the <jvmti/> version via <code>version_ptr</code>. 11352 The return value is the version identifier. 11353 The version identifier includes major, minor and micro 11354 version as well as the interface type. 11355 <constants id="jvmtiVersionInterfaceTypes" label="Version Interface Types" kind="bits"> 11356 <constant id="JVMTI_VERSION_INTERFACE_JNI" num="0x00000000"> 11357 Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for JNI. 11358 </constant> 11359 <constant id="JVMTI_VERSION_INTERFACE_JVMTI" num="0x30000000"> 11360 Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for <jvmti/>. 11361 </constant> 11362 </constants> 11363 <constants id="jvmtiVersionMasks" label="Version Masks" kind="bits"> 11364 <constant id="JVMTI_VERSION_MASK_INTERFACE_TYPE" num="0x70000000"> 11365 Mask to extract interface type. 11366 The value of the version returned by this function masked with 11367 <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> is always 11368 <code>JVMTI_VERSION_INTERFACE_JVMTI</code> 11369 since this is a <jvmti/> function. 11370 </constant> 11371 <constant id="JVMTI_VERSION_MASK_MAJOR" num="0x0FFF0000"> 11372 Mask to extract major version number. 11373 </constant> 11374 <constant id="JVMTI_VERSION_MASK_MINOR" num="0x0000FF00"> 11375 Mask to extract minor version number. 11376 </constant> 11377 <constant id="JVMTI_VERSION_MASK_MICRO" num="0x000000FF"> 11378 Mask to extract micro version number. 11379 </constant> 11380 </constants> 11381 <constants id="jvmtiVersionShifts" label="Version Shifts" kind="bits"> 11382 <constant id="JVMTI_VERSION_SHIFT_MAJOR" num="16"> 11383 Shift to extract major version number. 11384 </constant> 11385 <constant id="JVMTI_VERSION_SHIFT_MINOR" num="8"> 11386 Shift to extract minor version number. 11387 </constant> 11388 <constant id="JVMTI_VERSION_SHIFT_MICRO" num="0"> 11389 Shift to extract micro version number. 11390 </constant> 11391 </constants> 11392 </description> 11393 <origin>jvmdi</origin> 11394 <capabilities> 11395 </capabilities> 11396 <parameters> 11397 <param id="version_ptr"> 11398 <outptr><jint/></outptr> 11399 <description> 11400 On return, points to the <jvmti/> version. 11401 </description> 11402 </param> 11403 </parameters> 11404 <errors> 11405 </errors> 11406 </function> 11407 11408 11409 <function id="GetErrorName" phase="any" num="128"> 11410 <synopsis>Get Error Name</synopsis> 11411 <description> 11412 Return the symbolic name for an 11413 <internallink id="ErrorSection">error code</internallink>. 11414 <p/> 11415 For example 11416 <code>GetErrorName(env, JVMTI_ERROR_NONE, &err_name)</code> 11417 would return in <code>err_name</code> the string 11418 <code>"JVMTI_ERROR_NONE"</code>. 11419 </description> 11420 <origin>new</origin> 11421 <capabilities> 11422 </capabilities> 11423 <parameters> 11424 <param id="error"> 11425 <enum>jvmtiError</enum> 11426 <description> 11427 The error code. 11428 </description> 11429 </param> 11430 <param id="name_ptr"> 11431 <allocbuf><char/></allocbuf> 11432 <description> 11433 On return, points to the error name. 11434 The name is encoded as a 11435 <internallink id="mUTF">modified UTF-8</internallink> string, 11436 but is restricted to the ASCII subset. 11437 </description> 11438 </param> 11439 </parameters> 11440 <errors> 11441 </errors> 11442 </function> 11443 11444 <function id="SetVerboseFlag" phase="any" num="150"> 11445 <synopsis>Set Verbose Flag</synopsis> 11446 <description> 11447 <constants id="jvmtiVerboseFlag" label="Verbose Flag Enumeration" kind="enum"> 11448 <constant id="JVMTI_VERBOSE_OTHER" num="0"> 11449 Verbose output other than the below. 11450 </constant> 11451 <constant id="JVMTI_VERBOSE_GC" num="1"> 11452 Verbose garbage collector output, like that specified with <code>-verbose:gc</code>. 11453 </constant> 11454 <constant id="JVMTI_VERBOSE_CLASS" num="2"> 11455 Verbose class loading output, like that specified with <code>-verbose:class</code>. 11456 </constant> 11457 <constant id="JVMTI_VERBOSE_JNI" num="4"> 11458 Verbose JNI output, like that specified with <code>-verbose:jni</code>. 11459 </constant> 11460 </constants> 11461 Control verbose output. 11462 This is the output which typically is sent to <code>stderr</code>. 11463 </description> 11464 <origin>new</origin> 11465 <capabilities> 11466 </capabilities> 11467 <parameters> 11468 <param id="flag"> 11469 <enum>jvmtiVerboseFlag</enum> 11470 <description> 11471 Which verbose flag to set. 11472 </description> 11473 </param> 11474 <param id="value"> 11475 <jboolean/> 11476 <description> 11477 New value of the flag. 11478 </description> 11479 </param> 11480 </parameters> 11481 <errors> 11482 </errors> 11483 </function> 11484 11485 11486 <function id="GetJLocationFormat" phase="any" num="129"> 11487 <synopsis>Get JLocation Format</synopsis> 11488 <description> 11489 Although the greatest functionality is achieved with location information 11490 referencing the virtual machine bytecode index, the definition of 11491 <code>jlocation</code> has intentionally been left unconstrained to allow VM 11492 implementations that do not have this information. 11493 <p/> 11494 This function describes the representation of <code>jlocation</code> used in this VM. 11495 If the returned format is <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink>, 11496 <code>jlocation</code>s can 11497 be used as in indices into the array returned by 11498 <functionlink id="GetBytecodes"></functionlink>. 11499 <constants id="jvmtiJlocationFormat" label="JLocation Format Enumeration" kind="enum"> 11500 <constant id="JVMTI_JLOCATION_JVMBCI" num="1"> 11501 <code>jlocation</code> values represent virtual machine 11502 bytecode indices--that is, offsets into the 11503 virtual machine code for a method. 11504 </constant> 11505 <constant id="JVMTI_JLOCATION_MACHINEPC" num="2"> 11506 <code>jlocation</code> values represent native machine 11507 program counter values. 11508 </constant> 11509 <constant id="JVMTI_JLOCATION_OTHER" num="0"> 11510 <code>jlocation</code> values have some other representation. 11511 </constant> 11512 </constants> 11513 </description> 11514 <origin>new</origin> 11515 <capabilities> 11516 </capabilities> 11517 <parameters> 11518 <param id="format_ptr"> 11519 <outptr><enum>jvmtiJlocationFormat</enum></outptr> 11520 <description> 11521 On return, points to the format identifier for <code>jlocation</code> values. 11522 </description> 11523 </param> 11524 </parameters> 11525 <errors> 11526 </errors> 11527 </function> 11528 11529 </category> 11530 11531</functionsection> 11532 11533<errorsection label="Error Reference"> 11534 <intro> 11535 Every <jvmti/> function returns a <b><code>jvmtiError</code></b> error code. 11536 <p/> 11537 It is the responsibility of the agent to call <jvmti/> functions with 11538 valid parameters and in the proper context (calling thread is attached, 11539 phase is correct, etc.). 11540 Detecting some error conditions may be difficult, inefficient, or 11541 impossible for an implementation. 11542 The errors listed in 11543 <internallink id="reqerrors">Function Specific Required Errors</internallink> 11544 must be detected by the implementation. 11545 All other errors represent the recommended response to the error 11546 condition. 11547 </intro> 11548 11549 <errorcategory id="universal-error" label="Universal Errors"> 11550 <intro> 11551 The following errors may be returned by any function 11552 </intro> 11553 11554 <errorid id="JVMTI_ERROR_NONE" num="0"> 11555 No error has occurred. This is the error code that is returned 11556 on successful completion of the function. 11557 </errorid> 11558 <errorid id="JVMTI_ERROR_NULL_POINTER" num="100"> 11559 Pointer is unexpectedly <code>NULL</code>. 11560 </errorid> 11561 <errorid id="JVMTI_ERROR_OUT_OF_MEMORY" num="110"> 11562 The function attempted to allocate memory and no more memory was 11563 available for allocation. 11564 </errorid> 11565 <errorid id="JVMTI_ERROR_ACCESS_DENIED" num="111"> 11566 The desired functionality has not been enabled in this virtual machine. 11567 </errorid> 11568 <errorid id="JVMTI_ERROR_UNATTACHED_THREAD" num="115"> 11569 The thread being used to call this function is not attached 11570 to the virtual machine. Calls must be made from attached threads. 11571 See <code>AttachCurrentThread</code> in the JNI invocation API. 11572 </errorid> 11573 <errorid id="JVMTI_ERROR_INVALID_ENVIRONMENT" num="116"> 11574 The <jvmti/> environment provided is no longer connected or is 11575 not an environment. 11576 </errorid> 11577 <errorid id="JVMTI_ERROR_WRONG_PHASE" num="112"> 11578 The desired functionality is not available in the current 11579 <functionlink id="GetPhase">phase</functionlink>. 11580 Always returned if the virtual machine has completed running. 11581 </errorid> 11582 <errorid id="JVMTI_ERROR_INTERNAL" num="113"> 11583 An unexpected internal error has occurred. 11584 </errorid> 11585 </errorcategory> 11586 11587 <errorcategory id="reqerrors" label="Function Specific Required Errors"> 11588 <intro> 11589 The following errors are returned by some <jvmti/> functions and must 11590 be returned by the implementation when the condition occurs. 11591 </intro> 11592 11593 <errorid id="JVMTI_ERROR_INVALID_PRIORITY" num="12"> 11594 Invalid priority. 11595 </errorid> 11596 <errorid id="JVMTI_ERROR_THREAD_NOT_SUSPENDED" num="13"> 11597 Thread was not suspended. 11598 </errorid> 11599 <errorid id="JVMTI_ERROR_THREAD_SUSPENDED" num="14"> 11600 Thread already suspended. 11601 </errorid> 11602 <errorid id="JVMTI_ERROR_THREAD_NOT_ALIVE" num="15"> 11603 This operation requires the thread to be alive--that is, 11604 it must be started and not yet have died. 11605 </errorid> 11606 <errorid id="JVMTI_ERROR_CLASS_NOT_PREPARED" num="22"> 11607 The class has been loaded but not yet prepared. 11608 </errorid> 11609 <errorid id="JVMTI_ERROR_NO_MORE_FRAMES" num="31"> 11610 There are no Java programming language or JNI stack frames at the specified depth. 11611 </errorid> 11612 <errorid id="JVMTI_ERROR_OPAQUE_FRAME" num="32"> 11613 Information about the frame is not available (e.g. for native frames). 11614 </errorid> 11615 <errorid id="JVMTI_ERROR_DUPLICATE" num="40"> 11616 Item already set. 11617 </errorid> 11618 <errorid id="JVMTI_ERROR_NOT_FOUND" num="41"> 11619 Desired element (e.g. field or breakpoint) not found 11620 </errorid> 11621 <errorid id="JVMTI_ERROR_NOT_MONITOR_OWNER" num="51"> 11622 This thread doesn't own the raw monitor. 11623 </errorid> 11624 <errorid id="JVMTI_ERROR_INTERRUPT" num="52"> 11625 The call has been interrupted before completion. 11626 </errorid> 11627 <errorid id="JVMTI_ERROR_UNMODIFIABLE_CLASS" num="79"> 11628 The class cannot be modified. 11629 </errorid> 11630 <errorid id="JVMTI_ERROR_UNMODIFIABLE_MODULE" num="80"> 11631 The module cannot be modified. 11632 </errorid> 11633 <errorid id="JVMTI_ERROR_NOT_AVAILABLE" num="98"> 11634 The functionality is not available in this virtual machine. 11635 </errorid> 11636 <errorid id="JVMTI_ERROR_ABSENT_INFORMATION" num="101"> 11637 The requested information is not available. 11638 </errorid> 11639 <errorid id="JVMTI_ERROR_INVALID_EVENT_TYPE" num="102"> 11640 The specified event type ID is not recognized. 11641 </errorid> 11642 <errorid id="JVMTI_ERROR_NATIVE_METHOD" num="104"> 11643 The requested information is not available for native method. 11644 </errorid> 11645 <errorid id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED" num="106"> 11646 The class loader does not support this operation. 11647 </errorid> 11648 </errorcategory> 11649 11650 <errorcategory id="function-specific-errors" label="Function Specific Agent Errors"> 11651 <intro> 11652 The following errors are returned by some <jvmti/> functions. 11653 They are returned in the event of invalid parameters passed by the 11654 agent or usage in an invalid context. 11655 An implementation is not required to detect these errors. 11656 </intro> 11657 11658 <errorid id="JVMTI_ERROR_INVALID_THREAD" num="10"> 11659 The passed thread is not a valid thread. 11660 </errorid> 11661 <errorid id="JVMTI_ERROR_INVALID_FIELDID" num="25"> 11662 Invalid field. 11663 </errorid> 11664 <errorid id="JVMTI_ERROR_INVALID_MODULE" num="26"> 11665 Invalid module. 11666 </errorid> 11667 <errorid id="JVMTI_ERROR_INVALID_METHODID" num="23"> 11668 Invalid method. 11669 </errorid> 11670 <errorid id="JVMTI_ERROR_INVALID_LOCATION" num="24"> 11671 Invalid location. 11672 </errorid> 11673 <errorid id="JVMTI_ERROR_INVALID_OBJECT" num="20"> 11674 Invalid object. 11675 </errorid> 11676 <errorid id="JVMTI_ERROR_INVALID_CLASS" num="21"> 11677 Invalid class. 11678 </errorid> 11679 <errorid id="JVMTI_ERROR_TYPE_MISMATCH" num="34"> 11680 The variable is not an appropriate type for the function used. 11681 </errorid> 11682 <errorid id="JVMTI_ERROR_INVALID_SLOT" num="35"> 11683 Invalid slot. 11684 </errorid> 11685 <errorid id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY" num="99"> 11686 The capability being used is false in this environment. 11687 </errorid> 11688 <errorid id="JVMTI_ERROR_INVALID_THREAD_GROUP" num="11"> 11689 Thread group invalid. 11690 </errorid> 11691 <errorid id="JVMTI_ERROR_INVALID_MONITOR" num="50"> 11692 Invalid raw monitor. 11693 </errorid> 11694 <errorid id="JVMTI_ERROR_ILLEGAL_ARGUMENT" num="103"> 11695 Illegal argument. 11696 </errorid> 11697 <errorid id="JVMTI_ERROR_INVALID_TYPESTATE" num="65"> 11698 The state of the thread has been modified, and is now inconsistent. 11699 </errorid> 11700 <errorid id="JVMTI_ERROR_UNSUPPORTED_VERSION" num="68"> 11701 A new class file has a version number not supported by this VM. 11702 </errorid> 11703 <errorid id="JVMTI_ERROR_INVALID_CLASS_FORMAT" num="60"> 11704 A new class file is malformed (the VM would return a <code>ClassFormatError</code>). 11705 </errorid> 11706 <errorid id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION" num="61"> 11707 The new class file definitions would lead to a circular 11708 definition (the VM would return a <code>ClassCircularityError</code>). 11709 </errorid> 11710 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED" num="63"> 11711 A new class file would require adding a method. 11712 </errorid> 11713 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED" num="64"> 11714 A new class version changes a field. 11715 </errorid> 11716 <errorid id="JVMTI_ERROR_FAILS_VERIFICATION" num="62"> 11717 The class bytes fail verification. 11718 </errorid> 11719 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED" num="66"> 11720 A direct superclass is different for the new class 11721 version, or the set of directly implemented 11722 interfaces is different. 11723 </errorid> 11724 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED" num="67"> 11725 A new class version does not declare a method 11726 declared in the old class version. 11727 </errorid> 11728 <errorid id="JVMTI_ERROR_NAMES_DONT_MATCH" num="69"> 11729 The class name defined in the new class file is 11730 different from the name in the old class object. 11731 </errorid> 11732 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED" num="70"> 11733 A new class version has different modifiers. 11734 </errorid> 11735 <errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED" num="71"> 11736 A method in the new class version has different modifiers 11737 than its counterpart in the old class version. 11738 </errorid> 11739 </errorcategory> 11740</errorsection> 11741 11742<eventsection label="Events"> 11743 <intro label="Handling Events" id="eventIntro"> 11744 Agents can be informed of many events that occur in application 11745 programs. 11746 <p/> 11747 To handle events, designate a set of callback functions with 11748 <functionlink id="SetEventCallbacks"></functionlink>. 11749 For each event the corresponding callback function will be 11750 called. 11751 Arguments to the callback function provide additional 11752 information about the event. 11753 <p/> 11754 The callback function is usually called from within an application 11755 thread. The <jvmti/> implementation does not 11756 queue events in any way. This means 11757 that event callback functions must be written 11758 carefully. Here are some general guidelines. See 11759 the individual event descriptions for further 11760 suggestions. 11761 <p/> 11762 <ul> 11763 <li>Any exception thrown during the execution of an event callback can 11764 overwrite any current pending exception in the current application thread. 11765 Care must be taken to preserve a pending exception 11766 when an event callback makes a JNI call that might generate an exception. 11767 </li> 11768 <li>Event callback functions must be re-entrant. The <jvmti/> implementation does 11769 not queue events. If an agent needs to process events one at a time, it 11770 can use a raw monitor inside the 11771 event callback functions to serialize event processing. 11772 </li> 11773 <li>Event callback functions that execute JNI's FindClass function to load 11774 classes need to note that FindClass locates the class loader associated 11775 with the current native method. For the purposes of class loading, an 11776 event callback that includes a JNI environment as a parameter to the 11777 callback will treated as if it is a native call, where the native method 11778 is in the class of the event thread's current frame. 11779 </li> 11780 </ul> 11781 <p/> 11782 Some <jvmti/> events identify objects with JNI references. 11783 All references 11784 in <jvmti/> events are JNI local references and will become invalid 11785 after the event callback returns. 11786 Unless stated otherwise, memory referenced by pointers sent in event 11787 callbacks may not be referenced after the event callback returns. 11788 <p/> 11789 Except where stated otherwise, events are delivered on the thread 11790 that caused the event. 11791 Events are sent at the time they occur. 11792 The specification for each event includes the set of 11793 <functionlink id="GetPhase">phases</functionlink> in which it can be sent; 11794 if an event triggering activity occurs during another phase, no event 11795 is sent. 11796 <p/> 11797 A thread that generates an event does not change its execution status 11798 (for example, the event does not cause the thread to be suspended). 11799 If an agent wishes the event to result in suspension, then the agent 11800 is responsible for explicitly suspending the thread with 11801 <functionlink id="SuspendThread"></functionlink>. 11802 <p/> 11803 If an event is enabled in multiple environments, the event will be sent 11804 to each agent in the order that the environments were created. 11805 </intro> 11806 11807 <intro label="Enabling Events" id="enablingevents"> 11808 All events are initially disabled. In order to receive any 11809 event: 11810 <ul> 11811 <li> 11812 If the event requires a capability, that capability must 11813 be added with 11814 <functionlink id="AddCapabilities"></functionlink>. 11815 </li> 11816 <li> 11817 A callback for the event must be set with 11818 <functionlink id="SetEventCallbacks"></functionlink>. 11819 </li> 11820 <li> 11821 The event must be enabled with 11822 <functionlink id="SetEventNotificationMode"></functionlink>. 11823 </li> 11824 </ul> 11825 </intro> 11826 11827 <intro label="Multiple Co-located Events" id="eventorder"> 11828 In many situations it is possible for multiple events to occur 11829 at the same location in one thread. When this happens, all the events 11830 are reported through the event callbacks in the order specified in this section. 11831 <p/> 11832 If the current location is at the entry point of a method, the 11833 <eventlink id="MethodEntry"></eventlink> event is reported before 11834 any other event at the current location in the same thread. 11835 <p/> 11836 If an exception catch has been detected at the current location, 11837 either because it is the beginning of a catch clause or a native method 11838 that cleared a pending exception has returned, the 11839 <code>exceptionCatch</code> event is reported before 11840 any other event at the current location in the same thread. 11841 <p/> 11842 If a <code>singleStep</code> event or 11843 <code>breakpoint</code> event is triggered at the 11844 current location, the event is defined to occur 11845 immediately before the code at the current location is executed. 11846 These events are reported before any events which are triggered 11847 by the execution of code at the current location in the same 11848 thread (specifically: 11849 <code>exception</code>, 11850 <code>fieldAccess</code>, and 11851 <code>fieldModification</code>). 11852 If both a step and breakpoint event are triggered for the same thread and 11853 location, the step event is reported before the breakpoint event. 11854 <p/> 11855 If the current location is the exit point of a method (that is, the last 11856 location before returning to the caller), the 11857 <eventlink id="MethodExit"></eventlink> event and 11858 the <eventlink id="FramePop"></eventlink> event (if requested) 11859 are reported after all other events at the current location in the same 11860 thread. There is no specified ordering of these two events 11861 with respect to each other. 11862 <p/> 11863 Co-located events can be triggered during the processing of some other 11864 event by the agent at the same location in the same thread. 11865 If such an event, of type <i>y</i>, is triggered during the processing of 11866 an event of type <i>x</i>, and if <i>x</i> 11867 precedes <i>y</i> in the ordering specified above, the co-located event 11868 <i>y</i> is reported for the current thread and location. If <i>x</i> does not precede 11869 <i>y</i>, <i>y</i> is not reported for the current thread and location. 11870 For example, if a breakpoint is set at the current location 11871 during the processing of <eventlink id="SingleStep"></eventlink>, 11872 that breakpoint will be reported before the thread moves off the current 11873 location. 11874 <p/>The following events are never considered to be co-located with 11875 other events. 11876 <ul> 11877 <li><eventlink id="VMStart"></eventlink></li> 11878 <li><eventlink id="VMInit"></eventlink></li> 11879 <li><eventlink id="VMDeath"></eventlink></li> 11880 <li><eventlink id="ThreadStart"></eventlink></li> 11881 <li><eventlink id="ThreadEnd"></eventlink></li> 11882 <li><eventlink id="ClassLoad"></eventlink></li> 11883 <li><eventlink id="ClassPrepare"></eventlink></li> 11884 </ul> 11885 </intro> 11886 11887 <intro label="Event Callbacks" id="jvmtiEventCallbacks"> 11888 The event callback structure below is used to specify the handler function 11889 for events. It is set with the 11890 <functionlink id="SetEventCallbacks"></functionlink> function. 11891 </intro> 11892 11893 <event label="Single Step" 11894 id="SingleStep" const="JVMTI_EVENT_SINGLE_STEP" filtered="thread" num="60"> 11895 <description> 11896 Single step events allow the agent to trace thread execution 11897 at the finest granularity allowed by the VM. A single step event is 11898 generated whenever a thread reaches a new location. 11899 Typically, single step events represent the completion of one VM 11900 instruction as defined in <vmspec/>. However, some implementations 11901 may define locations differently. In any case the 11902 <code>method</code> and <code>location</code> 11903 parameters uniquely identify the current location and allow 11904 the mapping to source file and line number when that information is 11905 available. 11906 <p/> 11907 No single step events are generated from within native methods. 11908 </description> 11909 <origin>jvmdi</origin> 11910 <capabilities> 11911 <required id="can_generate_single_step_events"></required> 11912 </capabilities> 11913 <parameters> 11914 <param id="jni_env"> 11915 <outptr> 11916 <struct>JNIEnv</struct> 11917 </outptr> 11918 <description> 11919 The JNI environment of the event (current) thread 11920 </description> 11921 </param> 11922 <param id="thread"> 11923 <jthread/> 11924 <description> 11925 Thread about to execution a new instruction 11926 </description> 11927 </param> 11928 <param id="klass"> 11929 <jclass method="method"/> 11930 <description> 11931 Class of the method about to execute a new instruction 11932 </description> 11933 </param> 11934 <param id="method"> 11935 <jmethodID class="klass"/> 11936 <description> 11937 Method about to execute a new instruction 11938 </description> 11939 </param> 11940 <param id="location"> 11941 <jlocation/> 11942 <description> 11943 Location of the new instruction 11944 </description> 11945 </param> 11946 </parameters> 11947 </event> 11948 11949 <event label="Breakpoint" 11950 id="Breakpoint" const="JVMTI_EVENT_BREAKPOINT" filtered="thread" num="62"> 11951 <description> 11952 Breakpoint events are generated whenever a thread reaches a location 11953 designated as a breakpoint with <functionlink id="SetBreakpoint"></functionlink>. 11954 The <code>method</code> and <code>location</code> 11955 parameters uniquely identify the current location and allow 11956 the mapping to source file and line number when that information is 11957 available. 11958 </description> 11959 <origin>jvmdi</origin> 11960 <capabilities> 11961 <required id="can_generate_breakpoint_events"></required> 11962 </capabilities> 11963 <parameters> 11964 <param id="jni_env"> 11965 <outptr> 11966 <struct>JNIEnv</struct> 11967 </outptr> 11968 <description> 11969 The JNI environment of the event (current) thread. 11970 </description> 11971 </param> 11972 <param id="thread"> 11973 <jthread/> 11974 <description> 11975 Thread that hit the breakpoint 11976 </description> 11977 </param> 11978 <param id="klass"> 11979 <jclass method="method"/> 11980 <description> 11981 Class of the method that hit the breakpoint 11982 </description> 11983 </param> 11984 <param id="method"> 11985 <jmethodID class="klass"/> 11986 <description> 11987 Method that hit the breakpoint 11988 </description> 11989 </param> 11990 <param id="location"> 11991 <jlocation/> 11992 <description> 11993 location of the breakpoint 11994 </description> 11995 </param> 11996 </parameters> 11997 </event> 11998 11999 <event label="Field Access" 12000 id="FieldAccess" const="JVMTI_EVENT_FIELD_ACCESS" filtered="thread" num="63"> 12001 <description> 12002 Field access events are generated whenever a thread accesses 12003 a field that was designated as a watchpoint 12004 with <functionlink id="SetFieldAccessWatch"></functionlink>. 12005 The <code>method</code> and <code>location</code> 12006 parameters uniquely identify the current location and allow 12007 the mapping to source file and line number when that information is 12008 available. 12009 </description> 12010 <origin>jvmdi</origin> 12011 <capabilities> 12012 <required id="can_generate_field_access_events"></required> 12013 </capabilities> 12014 <parameters> 12015 <param id="jni_env"> 12016 <outptr> 12017 <struct>JNIEnv</struct> 12018 </outptr> 12019 <description> 12020 The JNI environment of the event (current) thread 12021 </description> 12022 </param> 12023 <param id="thread"> 12024 <jthread/> 12025 <description> 12026 Thread accessing the field 12027 </description> 12028 </param> 12029 <param id="klass"> 12030 <jclass method="method"/> 12031 <description> 12032 Class of the method where the access is occurring 12033 </description> 12034 </param> 12035 <param id="method"> 12036 <jmethodID class="klass"/> 12037 <description> 12038 Method where the access is occurring 12039 </description> 12040 </param> 12041 <param id="location"> 12042 <jlocation/> 12043 <description> 12044 Location where the access is occurring 12045 </description> 12046 </param> 12047 <param id="field_klass"> 12048 <jclass field="field"/> 12049 <description> 12050 Class of the field being accessed 12051 </description> 12052 </param> 12053 <param id="object"> 12054 <jobject/> 12055 <description> 12056 Object with the field being accessed if the field is an 12057 instance field; <code>NULL</code> otherwise 12058 </description> 12059 </param> 12060 <param id="field"> 12061 <jfieldID class="field_klass"/> 12062 <description> 12063 Field being accessed 12064 </description> 12065 </param> 12066 </parameters> 12067 </event> 12068 12069 <event label="Field Modification" 12070 id="FieldModification" const="JVMTI_EVENT_FIELD_MODIFICATION" filtered="thread" num="64"> 12071 <description> 12072 Field modification events are generated whenever a thread modifies 12073 a field that was designated as a watchpoint 12074 with <functionlink id="SetFieldModificationWatch"></functionlink>. 12075 The <code>method</code> and <code>location</code> 12076 parameters uniquely identify the current location and allow 12077 the mapping to source file and line number when that information is 12078 available. 12079 </description> 12080 <origin>jvmdi</origin> 12081 <capabilities> 12082 <required id="can_generate_field_modification_events"></required> 12083 </capabilities> 12084 <parameters> 12085 <param id="jni_env"> 12086 <outptr> 12087 <struct>JNIEnv</struct> 12088 </outptr> 12089 <description> 12090 The JNI environment of the event (current) thread 12091 </description> 12092 </param> 12093 <param id="thread"> 12094 <jthread/> 12095 <description> 12096 Thread modifying the field 12097 </description> 12098 </param> 12099 <param id="klass"> 12100 <jclass method="method"/> 12101 <description> 12102 Class of the method where the modification is occurring 12103 </description> 12104 </param> 12105 <param id="method"> 12106 <jmethodID class="klass"/> 12107 <description> 12108 Method where the modification is occurring 12109 </description> 12110 </param> 12111 <param id="location"> 12112 <jlocation/> 12113 <description> 12114 Location where the modification is occurring 12115 </description> 12116 </param> 12117 <param id="field_klass"> 12118 <jclass field="field"/> 12119 <description> 12120 Class of the field being modified 12121 </description> 12122 </param> 12123 <param id="object"> 12124 <jobject/> 12125 <description> 12126 Object with the field being modified if the field is an 12127 instance field; <code>NULL</code> otherwise 12128 </description> 12129 </param> 12130 <param id="field"> 12131 <jfieldID class="field_klass"/> 12132 <description> 12133 Field being modified 12134 </description> 12135 </param> 12136 <param id="signature_type"> 12137 <char/> 12138 <description> 12139 Signature type of the new value 12140 </description> 12141 </param> 12142 <param id="new_value"> 12143 <jvalue/> 12144 <description> 12145 The new value 12146 </description> 12147 </param> 12148 </parameters> 12149 </event> 12150 12151 <event label="Frame Pop" 12152 id="FramePop" const="JVMTI_EVENT_FRAME_POP" filtered="thread" num="61"> 12153 <description> 12154 Frame pop events are generated upon exit from a single method 12155 in a single frame as specified 12156 in a call to <functionlink id="NotifyFramePop"></functionlink>. 12157 This is true whether termination is caused by 12158 executing its return instruction 12159 or by throwing an exception to its caller 12160 (see <paramlink id="was_popped_by_exception"></paramlink>). 12161 However, frame pops caused by the <functionlink id="PopFrame"/> 12162 function are not reported. 12163 <p/> 12164 The location reported by <functionlink id="GetFrameLocation"></functionlink> 12165 identifies the executable location in the returning method, 12166 immediately prior to the return. 12167 </description> 12168 <origin>jvmdi</origin> 12169 <capabilities> 12170 <required id="can_generate_frame_pop_events"></required> 12171 </capabilities> 12172 <parameters> 12173 <param id="jni_env"> 12174 <outptr> 12175 <struct>JNIEnv</struct> 12176 </outptr> 12177 <description> 12178 The JNI environment of the event (current) thread 12179 </description> 12180 </param> 12181 <param id="thread"> 12182 <jthread/> 12183 <description> 12184 Thread that is popping the frame 12185 </description> 12186 </param> 12187 <param id="klass"> 12188 <jclass method="method"/> 12189 <description> 12190 Class of the method being popped 12191 </description> 12192 </param> 12193 <param id="method"> 12194 <jmethodID class="klass"/> 12195 <description> 12196 Method being popped 12197 </description> 12198 </param> 12199 <param id="was_popped_by_exception"> 12200 <jboolean/> 12201 <description> 12202 True if frame was popped by a thrown exception. 12203 False if method exited through its return instruction. 12204 </description> 12205 </param> 12206 </parameters> 12207 </event> 12208 12209 <event label="Method Entry" 12210 id="MethodEntry" const="JVMTI_EVENT_METHOD_ENTRY" filtered="thread" num="65"> 12211 <description> 12212 Method entry events are generated upon entry of Java 12213 programming language methods (including native methods). 12214 <p/> 12215 The location reported by <functionlink id="GetFrameLocation"></functionlink> 12216 identifies the initial executable location in 12217 the method. 12218 <p/> 12219 Enabling method 12220 entry or exit events will significantly degrade performance on many platforms and is thus 12221 not advised for performance critical usage (such as profiling). 12222 <internallink id="bci">Bytecode instrumentation</internallink> should be 12223 used in these cases. 12224 </description> 12225 <origin>jvmdi</origin> 12226 <capabilities> 12227 <required id="can_generate_method_entry_events"></required> 12228 </capabilities> 12229 <parameters> 12230 <param id="jni_env"> 12231 <outptr> 12232 <struct>JNIEnv</struct> 12233 </outptr> 12234 <description> 12235 The JNI environment of the event (current) thread 12236 </description> 12237 </param> 12238 <param id="thread"> 12239 <jthread/> 12240 <description> 12241 Thread entering the method 12242 </description> 12243 </param> 12244 <param id="klass"> 12245 <jclass method="method"/> 12246 <description> 12247 Class of the method being entered 12248 </description> 12249 </param> 12250 <param id="method"> 12251 <jmethodID class="klass"/> 12252 <description> 12253 Method being entered 12254 </description> 12255 </param> 12256 </parameters> 12257 </event> 12258 12259 <event label="Method Exit" 12260 id="MethodExit" const="JVMTI_EVENT_METHOD_EXIT" filtered="thread" num="66"> 12261 <description> 12262 Method exit events are generated upon exit from Java 12263 programming language methods (including native methods). 12264 This is true whether termination is caused by 12265 executing its return instruction 12266 or by throwing an exception to its caller 12267 (see <paramlink id="was_popped_by_exception"></paramlink>). 12268 <p/> 12269 The <code>method</code> field uniquely identifies the 12270 method being entered or exited. The <code>frame</code> field provides 12271 access to the stack frame for the method. 12272 <p/> 12273 The location reported by <functionlink id="GetFrameLocation"></functionlink> 12274 identifies the executable location in the returning method 12275 immediately prior to the return. 12276 <p/> 12277 Enabling method 12278 entry or exit events will significantly degrade performance on many platforms and is thus 12279 not advised for performance critical usage (such as profiling). 12280 <internallink id="bci">Bytecode instrumentation</internallink> should be 12281 used in these cases. 12282 </description> 12283 <origin>jvmdi</origin> 12284 <capabilities> 12285 <required id="can_generate_method_exit_events"></required> 12286 </capabilities> 12287 <parameters> 12288 <param id="jni_env"> 12289 <outptr> 12290 <struct>JNIEnv</struct> 12291 </outptr> 12292 <description> 12293 The JNI environment of the event (current) thread 12294 </description> 12295 </param> 12296 <param id="thread"> 12297 <jthread/> 12298 <description> 12299 Thread exiting the method 12300 </description> 12301 </param> 12302 <param id="klass"> 12303 <jclass method="method"/> 12304 <description> 12305 Class of the method being exited 12306 </description> 12307 </param> 12308 <param id="method"> 12309 <jmethodID class="klass"/> 12310 <description> 12311 Method being exited 12312 </description> 12313 </param> 12314 <param id="was_popped_by_exception"> 12315 <jboolean/> 12316 <description> 12317 True if frame was popped by a thrown exception. 12318 False if method exited through its return instruction. 12319 </description> 12320 </param> 12321 <param id="return_value"> 12322 <jvalue/> 12323 <description> 12324 The return value of the method being exited. 12325 Undefined and should not be used if 12326 <paramlink id="was_popped_by_exception"></paramlink> 12327 is true. 12328 </description> 12329 </param> 12330 </parameters> 12331 </event> 12332 12333 <event label="Native Method Bind" phase="any" 12334 id="NativeMethodBind" const="JVMTI_EVENT_NATIVE_METHOD_BIND" num="67"> 12335 <description> 12336 A Native Method Bind event is sent when a VM binds a 12337 Java programming language native method 12338 to the address of a function that implements the native method. 12339 This will occur when the native method is called for the first time 12340 and also occurs when the JNI function <code>RegisterNatives</code> is called. 12341 This event allows the bind to be redirected to an agent-specified 12342 proxy function. 12343 This event is not sent when the native method is unbound. 12344 Typically, this proxy function will need to be specific to a 12345 particular method or, to handle the general case, automatically 12346 generated assembly code, since after instrumentation code is 12347 executed the function at the original binding 12348 address will usually be invoked. 12349 The original binding can be restored or the redirection changed 12350 by use of the JNI function <code>RegisterNatives</code>. 12351 Some events may be sent during the primordial phase, JNI and 12352 most of <jvmti/> cannot be used at this time but the method and 12353 address can be saved for use later. 12354 </description> 12355 <origin>new</origin> 12356 <capabilities> 12357 <required id="can_generate_native_method_bind_events"></required> 12358 </capabilities> 12359 <parameters> 12360 <param id="jni_env"> 12361 <outptr> 12362 <struct>JNIEnv</struct> 12363 </outptr> 12364 <description> 12365 The JNI environment of the event (current) thread 12366 Will be <code>NULL</code> if sent during the primordial 12367 <functionlink id="GetPhase">phase</functionlink>. 12368 </description> 12369 </param> 12370 <param id="thread"> 12371 <jthread/> 12372 <description> 12373 Thread requesting the bind 12374 </description> 12375 </param> 12376 <param id="klass"> 12377 <jclass method="method"/> 12378 <description> 12379 Class of the method being bound 12380 </description> 12381 </param> 12382 <param id="method"> 12383 <jmethodID class="klass"/> 12384 <description> 12385 Native method being bound 12386 </description> 12387 </param> 12388 <param id="address"> 12389 <outptr><void/></outptr> 12390 <description> 12391 The address the VM is about to bind to--that is, the 12392 address of the implementation of the native method 12393 </description> 12394 </param> 12395 <param id="new_address_ptr"> 12396 <agentbuf><void/></agentbuf> 12397 <description> 12398 if the referenced address is changed (that is, if 12399 <code>*new_address_ptr</code> is set), the binding 12400 will instead be made to the supplied address. 12401 </description> 12402 </param> 12403 </parameters> 12404 </event> 12405 12406 <event label="Exception" 12407 id="Exception" const="JVMTI_EVENT_EXCEPTION" filtered="thread" num="58"> 12408 <description> 12409 Exception events are generated whenever an exception is first detected 12410 in a Java programming language method. 12411 Where "exception" means any <code>java.lang.Throwable</code>. 12412 The exception may have been thrown by a Java programming language or native 12413 method, but in the case of native methods, the event is not generated 12414 until the exception is first seen by a Java programming language method. If an exception is 12415 set and cleared in a native method (and thus is never visible to Java programming language code), 12416 no exception event is generated. 12417 <p/> 12418 The <code>method</code> and <code>location</code> 12419 parameters uniquely identify the current location 12420 (where the exception was detected) and allow 12421 the mapping to source file and line number when that information is 12422 available. The <code>exception</code> field identifies the thrown 12423 exception object. The <code>catch_method</code> 12424 and <code>catch_location</code> identify the location of the catch clause, 12425 if any, that handles the thrown exception. If there is no such catch clause, 12426 each field is set to 0. There is no guarantee that the thread will ever 12427 reach this catch clause. If there are native methods on the call stack 12428 between the throw location and the catch clause, the exception may 12429 be reset by one of those native methods. 12430 Similarly, exceptions that are reported as uncaught (<code>catch_klass</code> 12431 et al. set to 0) may in fact be caught by native code. 12432 Agents can check for these occurrences by monitoring 12433 <eventlink id="ExceptionCatch"></eventlink> events. 12434 Note that finally clauses are implemented as catch and re-throw. Therefore they 12435 will be reported in the catch location. 12436 </description> 12437 <origin>jvmdi</origin> 12438 <capabilities> 12439 <required id="can_generate_exception_events"></required> 12440 </capabilities> 12441 <parameters> 12442 <param id="jni_env"> 12443 <outptr> 12444 <struct>JNIEnv</struct> 12445 </outptr> 12446 <description> 12447 The JNI environment of the event (current) thread 12448 </description> 12449 </param> 12450 <param id="thread"> 12451 <jthread/> 12452 <description> 12453 Thread generating the exception 12454 </description> 12455 </param> 12456 <param id="klass"> 12457 <jclass method="method"/> 12458 <description> 12459 Class generating the exception 12460 </description> 12461 </param> 12462 <param id="method"> 12463 <jmethodID class="klass"/> 12464 <description> 12465 Method generating the exception 12466 </description> 12467 </param> 12468 <param id="location"> 12469 <jlocation/> 12470 <description> 12471 Location where exception occurred 12472 </description> 12473 </param> 12474 <param id="exception"> 12475 <jobject/> 12476 <description> 12477 The exception being thrown 12478 </description> 12479 </param> 12480 <param id="catch_klass"> 12481 <jclass method="catch_method"/> 12482 <description> 12483 Class that will catch the exception, or <code>NULL</code> if no known catch 12484 </description> 12485 </param> 12486 <param id="catch_method"> 12487 <jmethodID class="catch_klass"/> 12488 <description> 12489 Method that will catch the exception, or <code>NULL</code> if no known catch 12490 </description> 12491 </param> 12492 <param id="catch_location"> 12493 <jlocation/> 12494 <description> 12495 location which will catch the exception or zero if no known catch 12496 </description> 12497 </param> 12498 </parameters> 12499 </event> 12500 12501 <event label="Exception Catch" 12502 id="ExceptionCatch" const="JVMTI_EVENT_EXCEPTION_CATCH" filtered="thread" num="59"> 12503 <description> 12504 Exception catch events are generated whenever a thrown exception is caught. 12505 Where "exception" means any <code>java.lang.Throwable</code>. 12506 If the exception is caught in a Java programming language method, the event is generated 12507 when the catch clause is reached. If the exception is caught in a native 12508 method, the event is generated as soon as control is returned to a Java programming language 12509 method. Exception catch events are generated for any exception for which 12510 a throw was detected in a Java programming language method. 12511 Note that finally clauses are implemented as catch and re-throw. Therefore they 12512 will generate exception catch events. 12513 <p/> 12514 The <code>method</code> and <code>location</code> 12515 parameters uniquely identify the current location 12516 and allow the mapping to source file and line number when that information is 12517 available. For exceptions caught in a Java programming language method, the 12518 <code>exception</code> object identifies the exception object. Exceptions 12519 caught in native methods are not necessarily available by the time the 12520 exception catch is reported, so the <code>exception</code> field is set 12521 to <code>NULL</code>. 12522 </description> 12523 <origin>jvmdi</origin> 12524 <capabilities> 12525 <required id="can_generate_exception_events"></required> 12526 </capabilities> 12527 <parameters> 12528 <param id="jni_env"> 12529 <outptr> 12530 <struct>JNIEnv</struct> 12531 </outptr> 12532 <description> 12533 The JNI environment of the event (current) thread 12534 </description> 12535 </param> 12536 <param id="thread"> 12537 <jthread/> 12538 <description> 12539 Thread catching the exception 12540 </description> 12541 </param> 12542 <param id="klass"> 12543 <jclass method="method"/> 12544 <description> 12545 Class catching the exception 12546 </description> 12547 </param> 12548 <param id="method"> 12549 <jmethodID class="klass"/> 12550 <description> 12551 Method catching the exception 12552 </description> 12553 </param> 12554 <param id="location"> 12555 <jlocation/> 12556 <description> 12557 Location where exception is being caught 12558 </description> 12559 </param> 12560 <param id="exception"> 12561 <jobject/> 12562 <description> 12563 Exception being caught 12564 </description> 12565 </param> 12566 </parameters> 12567 </event> 12568 12569 <event label="Thread Start" 12570 id="ThreadStart" const="JVMTI_EVENT_THREAD_START" num="52" phase="start"> 12571 <description> 12572 Thread start events are generated by a new thread before its initial 12573 method executes. 12574 <p/> 12575 A thread may be listed in the array returned by 12576 <functionlink id="GetAllThreads"></functionlink> 12577 before its thread start event is generated. 12578 It is possible for other events to be generated 12579 on a thread before its thread start event. 12580 <p/> 12581 The event is sent on the newly started <paramlink id="thread"></paramlink>. 12582 </description> 12583 <origin>jvmdi</origin> 12584 <capabilities> 12585 </capabilities> 12586 <parameters> 12587 <param id="jni_env"> 12588 <outptr> 12589 <struct>JNIEnv</struct> 12590 </outptr> 12591 <description> 12592 The JNI environment of the event (current) thread. 12593 </description> 12594 </param> 12595 <param id="thread"> 12596 <jthread/> 12597 <description> 12598 Thread starting 12599 </description> 12600 </param> 12601 </parameters> 12602 </event> 12603 12604 <event label="Thread End" 12605 id="ThreadEnd" const="JVMTI_EVENT_THREAD_END" filtered="thread" num="53" phase="start"> 12606 <description> 12607 Thread end events are generated by a terminating thread 12608 after its initial method has finished execution. 12609 <p/> 12610 A thread may be listed in the array returned by 12611 <functionlink id="GetAllThreads"></functionlink> 12612 after its thread end event is generated. 12613 No events are generated on a thread 12614 after its thread end event. 12615 <p/> 12616 The event is sent on the dying <paramlink id="thread"></paramlink>. 12617 </description> 12618 <origin>jvmdi</origin> 12619 <capabilities> 12620 </capabilities> 12621 <parameters> 12622 <param id="jni_env"> 12623 <outptr> 12624 <struct>JNIEnv</struct> 12625 </outptr> 12626 <description> 12627 The JNI environment of the event (current) thread. 12628 </description> 12629 </param> 12630 <param id="thread"> 12631 <jthread/> 12632 <description> 12633 Thread ending 12634 </description> 12635 </param> 12636 </parameters> 12637 </event> 12638 12639 <event label="Class Load" 12640 id="ClassLoad" const="JVMTI_EVENT_CLASS_LOAD" filtered="thread" phase="start" num="55"> 12641 <description> 12642 A class load event is generated when a class is first loaded. The order 12643 of class load events generated by a particular thread are guaranteed 12644 to match the order of class loading within that thread. 12645 Array class creation does not generate a class load event. 12646 The creation of a primitive class (for example, java.lang.Integer.TYPE) 12647 does not generate a class load event. 12648 <p/> 12649 This event is sent at an early stage in loading the class. As 12650 a result the class should be used carefully. Note, for example, 12651 that methods and fields are not yet loaded, so queries for methods, 12652 fields, subclasses, and so on will not give correct results. 12653 See "Loading of Classes and Interfaces" in the <i>Java Language 12654 Specification</i>. For most 12655 purposes the <eventlink id="ClassPrepare"></eventlink> event will 12656 be more useful. 12657 </description> 12658 <origin>jvmdi</origin> 12659 <capabilities> 12660 </capabilities> 12661 <parameters> 12662 <param id="jni_env"> 12663 <outptr> 12664 <struct>JNIEnv</struct> 12665 </outptr> 12666 <description> 12667 The JNI environment of the event (current) thread 12668 </description> 12669 </param> 12670 <param id="thread"> 12671 <jthread/> 12672 <description> 12673 Thread loading the class 12674 </description> 12675 </param> 12676 <param id="klass"> 12677 <jclass/> 12678 <description> 12679 Class being loaded 12680 </description> 12681 </param> 12682 </parameters> 12683 </event> 12684 12685 <elide> 12686 <event label="Class Unload" 12687 id="ClassUnload" const="JVMTI_EVENT_CLASS_UNLOAD" num="57"> 12688 <description> 12689 A class unload event is generated when the class is about to be unloaded. 12690 Class unload events take place during garbage collection and must be 12691 handled extremely carefully. The garbage collector holds many locks 12692 and has suspended all other threads, so the event handler cannot depend 12693 on the ability to acquire any locks. The class unload event handler should 12694 do as little as possible, perhaps by queuing information to be processed 12695 later. In particular, the <code>jclass</code> should be used only in 12696 the JNI function <code>isSameObject</code> or in the following <jvmti/> functions: 12697 <ul> 12698 <li><functionlink id="GetClassSignature"></functionlink></li> 12699 <li><functionlink id="GetSourceFileName"></functionlink></li> 12700 <li><functionlink id="IsInterface"></functionlink></li> 12701 <li><functionlink id="IsArrayClass"></functionlink></li> 12702 </ul> 12703 </description> 12704 <origin>jvmdi</origin> 12705 <capabilities> 12706 </capabilities> 12707 <parameters> 12708 <param id="jni_env"> 12709 <outptr> 12710 <struct>JNIEnv</struct> 12711 </outptr> 12712 <description> 12713 The JNI environment of the event (current) thread 12714 </description> 12715 </param> 12716 <param id="thread"> 12717 <jthread/> 12718 <description> 12719 Thread generating the class unload 12720 </description> 12721 </param> 12722 <param id="klass"> 12723 <jclass/> 12724 <description> 12725 Class being unloaded 12726 </description> 12727 </param> 12728 </parameters> 12729 </event> 12730 </elide> 12731 12732 <event label="Class Prepare" 12733 id="ClassPrepare" const="JVMTI_EVENT_CLASS_PREPARE" filtered="thread" phase="start" num="56"> 12734 <description> 12735 A class prepare event is generated when class preparation is complete. 12736 At this point, class fields, methods, and implemented interfaces are 12737 available, and no code from the class has been executed. Since array 12738 classes never have fields or methods, class prepare events are not 12739 generated for them. Class prepare events are not generated for 12740 primitive classes (for example, <code>java.lang.Integer.TYPE</code>). 12741 </description> 12742 <origin>jvmdi</origin> 12743 <capabilities> 12744 </capabilities> 12745 <parameters> 12746 <param id="jni_env"> 12747 <outptr> 12748 <struct>JNIEnv</struct> 12749 </outptr> 12750 <description> 12751 The JNI environment of the event (current) thread 12752 </description> 12753 </param> 12754 <param id="thread"> 12755 <jthread/> 12756 <description> 12757 Thread generating the class prepare 12758 </description> 12759 </param> 12760 <param id="klass"> 12761 <jclass/> 12762 <description> 12763 Class being prepared 12764 </description> 12765 </param> 12766 </parameters> 12767 </event> 12768 12769 <event label="Class File Load Hook" phase="any" 12770 id="ClassFileLoadHook" const="JVMTI_EVENT_CLASS_FILE_LOAD_HOOK" num="54"> 12771 <description> 12772 This event is sent when the VM obtains class file data, 12773 but before it constructs 12774 the in-memory representation for that class. 12775 This event is also sent when the class is being modified by the 12776 <functionlink id="RetransformClasses"/> function or 12777 the <functionlink id="RedefineClasses"/> function, 12778 called in any <jvmti/> environment. 12779 The agent can instrument 12780 the existing class file data sent by the VM to include profiling/debugging hooks. 12781 See the description of 12782 <internallink id="bci">bytecode instrumentation</internallink> 12783 for usage information. 12784 <p/> 12785 When the capabilities 12786 <internallink id="jvmtiCapabilities.can_generate_early_class_hook_events"> 12787 <code>can_generate_early_class_hook_events</code></internallink> and 12788 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events"> 12789 <code>can_generate_all_class_hook_events</code></internallink> 12790 are enabled then this event may be sent in the primordial phase. 12791 Otherwise, this event may be sent before the VM is initialized (the start 12792 <functionlink id="GetPhase">phase</functionlink>). 12793 Some classes might not be compatible 12794 with the function (eg. ROMized classes or implementation defined classes) and this event will 12795 not be generated for these classes. 12796 <p/> 12797 The agent must allocate the space for the modified 12798 class file data buffer 12799 using the memory allocation function 12800 <functionlink id="Allocate"></functionlink> because the 12801 VM is responsible for freeing the new class file data buffer 12802 using <functionlink id="Deallocate"></functionlink>. 12803 <p/> 12804 If the agent wishes to modify the class file, it must set 12805 <code>new_class_data</code> to point 12806 to the newly instrumented class file data buffer and set 12807 <code>new_class_data_len</code> to the length of that 12808 buffer before returning 12809 from this call. If no modification is desired, the agent simply 12810 does not set <code>new_class_data</code>. If multiple agents 12811 have enabled this event the results are chained. That is, if 12812 <code>new_class_data</code> has been set, it becomes the 12813 <code>class_data</code> for the next agent. 12814 <p/> 12815 When handling a class load in the live phase, then the 12816 <functionlink id="GetNamedModule"></functionlink> 12817 function can be used to map class loader and a package name to a module. 12818 When a class is being redefined or retransformed then 12819 <code>class_being_redefined</code> is non <code>NULL</code> and so 12820 the JNI <code>GetModule</code> function can also be used 12821 to obtain the Module. 12822 <p/> 12823 The order that this event is sent to each environment differs 12824 from other events. 12825 This event is sent to environments in the following order: 12826 <ul> 12827 <li><fieldlink id="can_retransform_classes" 12828 struct="jvmtiCapabilities">retransformation 12829 incapable</fieldlink> 12830 environments, in the 12831 order in which they were created 12832 </li> 12833 <li><fieldlink id="can_retransform_classes" 12834 struct="jvmtiCapabilities">retransformation 12835 capable</fieldlink> 12836 environments, in the 12837 order in which they were created 12838 </li> 12839 </ul> 12840 When triggered by <functionlink id="RetransformClasses"/>, 12841 this event is sent only to <fieldlink id="can_retransform_classes" 12842 struct="jvmtiCapabilities">retransformation 12843 capable</fieldlink> 12844 environments. 12845 </description> 12846 <origin>jvmpi</origin> 12847 <capabilities> 12848 <capability id="can_generate_all_class_hook_events"></capability> 12849 <capability id="can_generate_early_class_hook_events"></capability> 12850 </capabilities> 12851 <parameters> 12852 <param id="jni_env"> 12853 <outptr> 12854 <struct>JNIEnv</struct> 12855 </outptr> 12856 <description> 12857 The JNI environment of the event (current) thread. 12858 </description> 12859 </param> 12860 <param id="class_being_redefined"> 12861 <jclass/> 12862 <description> 12863 The class being 12864 <functionlink id="RedefineClasses">redefined</functionlink> or 12865 <functionlink id="RetransformClasses">retransformed</functionlink>. 12866 <code>NULL</code> if sent by class load. 12867 </description> 12868 </param> 12869 <param id="loader"> 12870 <jobject/> 12871 <description> 12872 The class loader loading the class. 12873 <code>NULL</code> if the bootstrap class loader. 12874 </description> 12875 </param> 12876 <param id="name"> 12877 <vmbuf><char/></vmbuf> 12878 <description> 12879 Name of class being loaded as a VM internal qualified name 12880 (for example, "java/util/List"), encoded as a 12881 <internallink id="mUTF">modified UTF-8</internallink> string. 12882 Note: if the class is defined with a <code>NULL</code> name or 12883 without a name specified, <code>name</code> will be <code>NULL</code>. 12884 </description> 12885 </param> 12886 <param id="protection_domain"> 12887 <jobject/> 12888 <description> 12889 The <code>ProtectionDomain</code> of the class. 12890 </description> 12891 </param> 12892 <param id="class_data_len"> 12893 <jint/> 12894 <description> 12895 Length of current class file data buffer. 12896 </description> 12897 </param> 12898 <param id="class_data"> 12899 <vmbuf><uchar/></vmbuf> 12900 <description> 12901 Pointer to the current class file data buffer. 12902 </description> 12903 </param> 12904 <param id="new_class_data_len"> 12905 <outptr><jint/></outptr> 12906 <description> 12907 Pointer to the length of the new class file data buffer. 12908 </description> 12909 </param> 12910 <param id="new_class_data"> 12911 <agentbuf incount="new_class_data_len"><uchar/></agentbuf> 12912 <description> 12913 Pointer to the pointer to the instrumented class file data buffer. 12914 </description> 12915 </param> 12916 </parameters> 12917 </event> 12918 12919 <event label="VM Start Event" 12920 id="VMStart" const="JVMTI_EVENT_VM_START" num="57" phase="start"> 12921 <description> 12922 The VM start event signals the start of the VM. 12923 At this time JNI is live but the VM is not yet fully initialized. 12924 Once this event is generated, the agent is free to call any JNI function. 12925 This event signals the beginning of the start phase, 12926 <jvmti/> functions permitted in the start phase may be called. 12927 <p/> 12928 The timing of this event may depend on whether the agent has added the 12929 <internallink id="jvmtiCapabilities.can_generate_early_vmstart"> 12930 <code>can_generate_early_vmstart</code></internallink> capability or not. 12931 If the capability has been added then the VM posts the event as early 12932 as possible. The VM is capable of executing bytecode but it may not have 12933 initialized to the point where it can load classes in modules other than 12934 <code>java.base</code>, or even arbitrary classes in <code>java.base</code>. 12935 Agents that do load-time instrumentation in this 12936 phase must take great care when instrumenting code that potentially 12937 executes in this phase. Extreme care should also be taken with JNI 12938 <code>FindClass</code> as it may not be possible to load classes and attempts 12939 to do so may result in unpredictable behavior, maybe even stability issues 12940 on some VM implementations. 12941 If the capability has not been added then the VM delays posting this 12942 event until it is capable of loading classes in modules other than 12943 <code>java.base</code> or the VM has completed its initialization. 12944 Agents that create more than one JVM TI environment, where the 12945 capability is added to some but not all environments, may observe the 12946 start phase beginning earlier in the JVM TI environments that possess 12947 the capabilty. 12948 <p/> 12949 In the case of VM start-up failure, this event will not be sent. 12950 </description> 12951 <origin>jvmdi</origin> 12952 <capabilities> 12953 </capabilities> 12954 <parameters> 12955 <param id="jni_env"> 12956 <outptr> 12957 <struct>JNIEnv</struct> 12958 </outptr> 12959 <description> 12960 The JNI environment of the event (current) thread. 12961 </description> 12962 </param> 12963 </parameters> 12964 </event> 12965 12966 <event label="VM Initialization Event" 12967 id="VMInit" const="JVMTI_EVENT_VM_INIT" num="50"> 12968 <description> 12969 The VM initialization event signals the completion of VM initialization. Once 12970 this event is generated, the agent is free to call any JNI or <jvmti/> 12971 function. The VM initialization event can be preceded by or can be concurrent 12972 with other events, but 12973 the preceding events should be handled carefully, if at all, because the 12974 VM has not completed its initialization. The thread start event for the 12975 main application thread is guaranteed not to occur until after the 12976 handler for the VM initialization event returns. 12977 <p/> 12978 In the case of VM start-up failure, this event will not be sent. 12979 </description> 12980 <origin>jvmdi</origin> 12981 <capabilities> 12982 </capabilities> 12983 <parameters> 12984 <param id="jni_env"> 12985 <outptr> 12986 <struct>JNIEnv</struct> 12987 </outptr> 12988 <description> 12989 The JNI environment of the event (current) thread. 12990 </description> 12991 </param> 12992 <param id="thread"> 12993 <jthread/> 12994 <description> 12995 The initial thread 12996 </description> 12997 </param> 12998 </parameters> 12999 </event> 13000 13001 <event label="VM Death Event" 13002 id="VMDeath" const="JVMTI_EVENT_VM_DEATH" num="51"> 13003 <description> 13004 The VM death event notifies the agent of the termination of the VM. 13005 No events will occur after the VMDeath event. 13006 <p/> 13007 In the case of VM start-up failure, this event will not be sent. 13008 Note that <internallink id="onunload">Agent_OnUnload</internallink> 13009 will still be called in these cases. 13010 </description> 13011 <origin>jvmdi</origin> 13012 <capabilities> 13013 </capabilities> 13014 <parameters> 13015 <param id="jni_env"> 13016 <outptr> 13017 <struct>JNIEnv</struct> 13018 </outptr> 13019 <description> 13020 The JNI environment of the event (current) thread 13021 </description> 13022 </param> 13023 </parameters> 13024 </event> 13025 13026 <event label="Compiled Method Load" phase="start" 13027 id="CompiledMethodLoad" const="JVMTI_EVENT_COMPILED_METHOD_LOAD" num="68"> 13028 <description> 13029 Sent when a method is compiled and loaded into memory by the VM. 13030 If it is unloaded, the <eventlink id="CompiledMethodUnload"/> event is sent. 13031 If it is moved, the <eventlink id="CompiledMethodUnload"/> event is sent, 13032 followed by a new <code>CompiledMethodLoad</code> event. 13033 Note that a single method may have multiple compiled forms, and that 13034 this event will be sent for each form. 13035 Note also that several methods may be inlined into a single 13036 address range, and that this event will be sent for each method. 13037 <p/> 13038 These events can be sent after their initial occurrence with 13039 <functionlink id="GenerateEvents"></functionlink>. 13040 </description> 13041 <origin>jvmpi</origin> 13042 <typedef id="jvmtiAddrLocationMap" label="Native address to location entry"> 13043 <field id="start_address"> 13044 <vmbuf><void/></vmbuf> 13045 <description> 13046 Starting native address of code corresponding to a location 13047 </description> 13048 </field> 13049 <field id="location"> 13050 <jlocation/> 13051 <description> 13052 Corresponding location. See 13053 <functionlink id="GetJLocationFormat"></functionlink> 13054 for the meaning of location. 13055 </description> 13056 </field> 13057 </typedef> 13058 <capabilities> 13059 <required id="can_generate_compiled_method_load_events"></required> 13060 </capabilities> 13061 <parameters> 13062 <param id="klass"> 13063 <jclass method="method"/> 13064 <description> 13065 Class of the method being compiled and loaded 13066 </description> 13067 </param> 13068 <param id="method"> 13069 <jmethodID class="klass"/> 13070 <description> 13071 Method being compiled and loaded 13072 </description> 13073 </param> 13074 <param id="code_size"> 13075 <jint/> 13076 <description> 13077 Size of compiled code 13078 </description> 13079 </param> 13080 <param id="code_addr"> 13081 <vmbuf><void/></vmbuf> 13082 <description> 13083 Address where compiled method code is loaded 13084 </description> 13085 </param> 13086 <param id="map_length"> 13087 <jint/> 13088 <description> 13089 Number of <typelink id="jvmtiAddrLocationMap"></typelink> 13090 entries in the address map. 13091 Zero if mapping information cannot be supplied. 13092 </description> 13093 </param> 13094 <param id="map"> 13095 <vmbuf><struct>jvmtiAddrLocationMap</struct></vmbuf> 13096 <description> 13097 Map from native addresses to location. 13098 The native address range of each entry is from 13099 <fieldlink id="start_address" struct="jvmtiAddrLocationMap"></fieldlink> 13100 to <code>start_address-1</code> of the next entry. 13101 <code>NULL</code> if mapping information cannot be supplied. 13102 </description> 13103 </param> 13104 <param id="compile_info"> 13105 <vmbuf><void/></vmbuf> 13106 <description> 13107 VM-specific compilation information. 13108 The referenced compile information is managed by the VM 13109 and must not depend on the agent for collection. 13110 A VM implementation defines the content and lifetime 13111 of the information. 13112 </description> 13113 </param> 13114 </parameters> 13115 </event> 13116 13117 <event label="Compiled Method Unload" phase="start" 13118 id="CompiledMethodUnload" const="JVMTI_EVENT_COMPILED_METHOD_UNLOAD" num="69"> 13119 <description> 13120 Sent when a compiled method is unloaded from memory. 13121 This event might not be sent on the thread which performed the unload. 13122 This event may be sent sometime after the unload occurs, but 13123 will be sent before the memory is reused 13124 by a newly generated compiled method. This event may be sent after 13125 the class is unloaded. 13126 </description> 13127 <origin>jvmpi</origin> 13128 <capabilities> 13129 <required id="can_generate_compiled_method_load_events"></required> 13130 </capabilities> 13131 <parameters> 13132 <param id="klass"> 13133 <jclass method="method"/> 13134 <description> 13135 Class of the compiled method being unloaded. 13136 </description> 13137 </param> 13138 <param id="method"> 13139 <jmethodID class="klass"/> 13140 <description> 13141 Compiled method being unloaded. 13142 For identification of the compiled method only -- the class 13143 may be unloaded and therefore the method should not be used 13144 as an argument to further JNI or <jvmti/> functions. 13145 </description> 13146 </param> 13147 <param id="code_addr"> 13148 <vmbuf><void/></vmbuf> 13149 <description> 13150 Address where compiled method code was loaded. 13151 For identification of the compiled method only -- 13152 the space may have been reclaimed. 13153 </description> 13154 </param> 13155 </parameters> 13156 </event> 13157 13158 <event label="Dynamic Code Generated" phase="any" 13159 id="DynamicCodeGenerated" const="JVMTI_EVENT_DYNAMIC_CODE_GENERATED" num="70"> 13160 <description> 13161 Sent when a component of the virtual machine is generated dynamically. 13162 This does not correspond to Java programming language code that is 13163 compiled--see <eventlink id="CompiledMethodLoad"></eventlink>. 13164 This is for native code--for example, an interpreter that is generated 13165 differently depending on command-line options. 13166 <p/> 13167 Note that this event has no controlling capability. 13168 If a VM cannot generate these events, it simply does not send any. 13169 <p/> 13170 These events can be sent after their initial occurrence with 13171 <functionlink id="GenerateEvents"></functionlink>. 13172 </description> 13173 <origin>jvmpi</origin> 13174 <capabilities> 13175 </capabilities> 13176 <parameters> 13177 <param id="name"> 13178 <vmbuf><char/></vmbuf> 13179 <description> 13180 Name of the code, encoded as a 13181 <internallink id="mUTF">modified UTF-8</internallink> string. 13182 Intended for display to an end-user. 13183 The name might not be unique. 13184 </description> 13185 </param> 13186 <param id="address"> 13187 <vmbuf><void/></vmbuf> 13188 <description> 13189 Native address of the code 13190 </description> 13191 </param> 13192 <param id="length"> 13193 <jint/> 13194 <description> 13195 Length in bytes of the code 13196 </description> 13197 </param> 13198 </parameters> 13199 </event> 13200 13201 <event label="Data Dump Request" 13202 id="DataDumpRequest" const="JVMTI_EVENT_DATA_DUMP_REQUEST" num="71"> 13203 <description> 13204 Sent by the VM to request the agent to dump its data. This 13205 is just a hint and the agent need not react to this event. 13206 This is useful for processing command-line signals from users. For 13207 example, in the Java 2 SDK a CTRL-Break on Win32 and a CTRL-\ on Solaris 13208 causes the VM to send this event to the agent. 13209 </description> 13210 <origin>jvmpi</origin> 13211 <capabilities> 13212 </capabilities> 13213 <parameters> 13214 </parameters> 13215 </event> 13216 13217 <event label="Monitor Contended Enter" 13218 id="MonitorContendedEnter" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTER" filtered="thread" num="75"> 13219 <description> 13220 Sent when a thread is attempting to enter a Java programming language 13221 monitor already acquired by another thread. 13222 </description> 13223 <origin>jvmpi</origin> 13224 <capabilities> 13225 <required id="can_generate_monitor_events"></required> 13226 </capabilities> 13227 <parameters> 13228 <param id="jni_env"> 13229 <outptr> 13230 <struct>JNIEnv</struct> 13231 </outptr> 13232 <description> 13233 The JNI environment of the event (current) thread 13234 </description> 13235 </param> 13236 <param id="thread"> 13237 <jthread/> 13238 <description> 13239 JNI local reference to the thread 13240 attempting to enter the monitor 13241 </description> 13242 </param> 13243 <param id="object"> 13244 <jobject/> 13245 <description> 13246 JNI local reference to the monitor 13247 </description> 13248 </param> 13249 </parameters> 13250 </event> 13251 13252 <event label="Monitor Contended Entered" 13253 id="MonitorContendedEntered" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTERED" filtered="thread" num="76"> 13254 <description> 13255 Sent when a thread enters a Java programming language 13256 monitor after waiting for it to be released by another thread. 13257 </description> 13258 <origin>jvmpi</origin> 13259 <capabilities> 13260 <required id="can_generate_monitor_events"></required> 13261 </capabilities> 13262 <parameters> 13263 <param id="jni_env"> 13264 <outptr> 13265 <struct>JNIEnv</struct> 13266 </outptr> 13267 <description> 13268 The JNI environment of the event (current) thread 13269 </description> 13270 </param> 13271 <param id="thread"> 13272 <jthread/> 13273 <description> 13274 JNI local reference to the thread entering 13275 the monitor 13276 </description> 13277 </param> 13278 <param id="object"> 13279 <jobject/> 13280 <description> 13281 JNI local reference to the monitor 13282 </description> 13283 </param> 13284 </parameters> 13285 </event> 13286 13287 <event label="Monitor Wait" 13288 id="MonitorWait" const="JVMTI_EVENT_MONITOR_WAIT" filtered="thread" num="73"> 13289 <description> 13290 Sent when a thread is about to wait on an object. 13291 </description> 13292 <origin>jvmpi</origin> 13293 <capabilities> 13294 <required id="can_generate_monitor_events"></required> 13295 </capabilities> 13296 <parameters> 13297 <param id="jni_env"> 13298 <outptr> 13299 <struct>JNIEnv</struct> 13300 </outptr> 13301 <description> 13302 The JNI environment of the event (current) thread 13303 </description> 13304 </param> 13305 <param id="thread"> 13306 <jthread/> 13307 <description> 13308 JNI local reference to the thread about to wait 13309 </description> 13310 </param> 13311 <param id="object"> 13312 <jobject/> 13313 <description> 13314 JNI local reference to the monitor 13315 </description> 13316 </param> 13317 <param id="timeout"> 13318 <jlong/> 13319 <description> 13320 The number of milliseconds the thread will wait 13321 </description> 13322 </param> 13323 </parameters> 13324 </event> 13325 13326 <event label="Monitor Waited" 13327 id="MonitorWaited" const="JVMTI_EVENT_MONITOR_WAITED" filtered="thread" num="74"> 13328 <description> 13329 Sent when a thread finishes waiting on an object. 13330 </description> 13331 <origin>jvmpi</origin> 13332 <capabilities> 13333 <required id="can_generate_monitor_events"></required> 13334 </capabilities> 13335 <parameters> 13336 <param id="jni_env"> 13337 <outptr> 13338 <struct>JNIEnv</struct> 13339 </outptr> 13340 <description> 13341 The JNI environment of the event (current) thread 13342 </description> 13343 </param> 13344 <param id="thread"> 13345 <jthread/> 13346 <description> 13347 JNI local reference to the thread that was finished waiting 13348 </description> 13349 </param> 13350 <param id="object"> 13351 <jobject/> 13352 <description> 13353 JNI local reference to the monitor. 13354 </description> 13355 </param> 13356 <param id="timed_out"> 13357 <jboolean/> 13358 <description> 13359 True if the monitor timed out 13360 </description> 13361 </param> 13362 </parameters> 13363 </event> 13364 13365 <event label="Resource Exhausted" 13366 id="ResourceExhausted" const="JVMTI_EVENT_RESOURCE_EXHAUSTED" num="80" 13367 since="1.1"> 13368 <description> 13369 Sent when a VM resource needed by a running application has been exhausted. 13370 Except as required by the optional capabilities, the set of resources 13371 which report exhaustion is implementation dependent. 13372 <p/> 13373 The following bit flags define the properties of the resource exhaustion: 13374 <constants id="jvmtiResourceExhaustionFlags" 13375 label="Resource Exhaustion Flags" 13376 kind="bits" 13377 since="1.1"> 13378 <constant id="JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR" num="0x0001"> 13379 After this event returns, the VM will throw a 13380 <code>java.lang.OutOfMemoryError</code>. 13381 </constant> 13382 <constant id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP" num="0x0002"> 13383 The VM was unable to allocate memory from the <tm>Java</tm> 13384 platform <i>heap</i>. 13385 The <i>heap</i> is the runtime 13386 data area from which memory for all class instances and 13387 arrays are allocated. 13388 </constant> 13389 <constant id="JVMTI_RESOURCE_EXHAUSTED_THREADS" num="0x0004"> 13390 The VM was unable to create a thread. 13391 </constant> 13392 </constants> 13393 </description> 13394 <origin>new</origin> 13395 <capabilities> 13396 <capability id="can_generate_resource_exhaustion_heap_events"> 13397 Can generate events when the VM is unable to allocate memory from the 13398 <internallink id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP">heap</internallink>. 13399 </capability> 13400 <capability id="can_generate_resource_exhaustion_threads_events"> 13401 Can generate events when the VM is unable to 13402 <internallink id="JVMTI_RESOURCE_EXHAUSTED_THREADS">create 13403 a thread</internallink>. 13404 </capability> 13405 </capabilities> 13406 <parameters> 13407 <param id="jni_env"> 13408 <outptr> 13409 <struct>JNIEnv</struct> 13410 </outptr> 13411 <description> 13412 The JNI environment of the event (current) thread 13413 </description> 13414 </param> 13415 <param id="flags"> 13416 <jint/> 13417 <description> 13418 Flags defining the properties of the of resource exhaustion 13419 as specified by the 13420 <internallink id="jvmtiResourceExhaustionFlags">Resource 13421 Exhaustion Flags</internallink>. 13422 </description> 13423 </param> 13424 <param id="reserved"> 13425 <vmbuf><void/></vmbuf> 13426 <description> 13427 Reserved. 13428 </description> 13429 </param> 13430 <param id="description"> 13431 <vmbuf><char/></vmbuf> 13432 <description> 13433 Description of the resource exhaustion, encoded as a 13434 <internallink id="mUTF">modified UTF-8</internallink> string. 13435 </description> 13436 </param> 13437 </parameters> 13438 </event> 13439 13440 <event label="VM Object Allocation" 13441 id="VMObjectAlloc" const="JVMTI_EVENT_VM_OBJECT_ALLOC" num="84"> 13442 <description> 13443 Sent when a method causes the virtual machine to allocate an 13444 Object visible to Java programming language code and the 13445 allocation is not detectable by other intrumentation mechanisms. 13446 Generally object allocation should be detected by instrumenting 13447 the bytecodes of allocating methods. 13448 Object allocation generated in native code by JNI function 13449 calls should be detected using 13450 <internallink id="jniIntercept">JNI function interception</internallink>. 13451 Some methods might not have associated bytecodes and are not 13452 native methods, they instead are executed directly by the 13453 VM. These methods should send this event. 13454 Virtual machines which are incapable of bytecode instrumentation 13455 for some or all of their methods can send this event. 13456 <p/> 13457 Typical examples where this event might be sent: 13458 <ul> 13459 <li>Reflection -- for example, <code>java.lang.Class.newInstance()</code></li> 13460 <li>Methods not represented by bytecodes -- for example, VM intrinsics and 13461 J2ME preloaded classes</li> 13462 </ul> 13463 Cases where this event would not be generated: 13464 <ul> 13465 <li>Allocation due to bytecodes -- for example, the <code>new</code> 13466 and <code>newarray</code> VM instructions</li> 13467 <li>Allocation due to JNI function calls -- for example, 13468 <code>AllocObject</code></li> 13469 <li>Allocations during VM initialization</li> 13470 <li>VM internal objects</li> 13471 </ul> 13472 </description> 13473 <origin>new</origin> 13474 <capabilities> 13475 <required id="can_generate_vm_object_alloc_events"></required> 13476 </capabilities> 13477 <parameters> 13478 <param id="jni_env"> 13479 <outptr> 13480 <struct>JNIEnv</struct> 13481 </outptr> 13482 <description> 13483 The JNI environment of the event (current) thread 13484 </description> 13485 </param> 13486 <param id="thread"> 13487 <jthread/> 13488 <description> 13489 Thread allocating the object. 13490 </description> 13491 </param> 13492 <param id="object"> 13493 <jobject/> 13494 <description> 13495 JNI local reference to the object that was allocated 13496 </description> 13497 </param> 13498 <param id="object_klass"> 13499 <jclass/> 13500 <description> 13501 JNI local reference to the class of the object 13502 </description> 13503 </param> 13504 <param id="size"> 13505 <jlong/> 13506 <description> 13507 Size of the object (in bytes). See <functionlink id="GetObjectSize"/>. 13508 </description> 13509 </param> 13510 </parameters> 13511 </event> 13512 13513 <event label="Object Free" 13514 id="ObjectFree" const="JVMTI_EVENT_OBJECT_FREE" num="83"> 13515 <description> 13516 An Object Free event is sent when the garbage collector frees an object. 13517 Events are only sent for tagged objects--see 13518 <internallink id="Heap">heap functions</internallink>. 13519 <p/> 13520 The event handler must not use JNI functions and 13521 must not use <jvmti/> functions except those which 13522 specifically allow such use (see the raw monitor, memory management, 13523 and environment local storage functions). 13524 </description> 13525 <origin>new</origin> 13526 <capabilities> 13527 <required id="can_generate_object_free_events"></required> 13528 </capabilities> 13529 <parameters> 13530 <param id="tag"> 13531 <jlong/> 13532 <description> 13533 The freed object's tag 13534 </description> 13535 </param> 13536 </parameters> 13537 </event> 13538 13539 <event label="Garbage Collection Start" 13540 id="GarbageCollectionStart" const="JVMTI_EVENT_GARBAGE_COLLECTION_START" num="81"> 13541 <description> 13542 A Garbage Collection Start event is sent when a 13543 garbage collection pause begins. 13544 Only stop-the-world collections are reported--that is, collections during 13545 which all threads cease to modify the state of the Java virtual machine. 13546 This means that some collectors will never generate these events. 13547 This event is sent while the VM is still stopped, thus 13548 the event handler must not use JNI functions and 13549 must not use <jvmti/> functions except those which 13550 specifically allow such use (see the raw monitor, memory management, 13551 and environment local storage functions). 13552 <p/> 13553 This event is always sent as a matched pair with 13554 <eventlink id="GarbageCollectionFinish"/> 13555 (assuming both events are enabled) and no garbage collection 13556 events will occur between them. 13557 </description> 13558 <origin>new</origin> 13559 <capabilities> 13560 <required id="can_generate_garbage_collection_events"></required> 13561 </capabilities> 13562 <parameters> 13563 </parameters> 13564 </event> 13565 13566 <event label="Garbage Collection Finish" 13567 id="GarbageCollectionFinish" const="JVMTI_EVENT_GARBAGE_COLLECTION_FINISH" num="82"> 13568 <description> 13569 A Garbage Collection Finish event is sent when a 13570 garbage collection pause ends. 13571 This event is sent while the VM is still stopped, thus 13572 the event handler must not use JNI functions and 13573 must not use <jvmti/> functions except those which 13574 specifically allow such use (see the raw monitor, memory management, 13575 and environment local storage functions). 13576 <p/> 13577 Some agents may need to do post garbage collection operations that 13578 require the use of the disallowed <jvmti/> or JNI functions. For these 13579 cases an agent thread can be created which waits on a raw monitor, 13580 and the handler for the Garbage Collection Finish event simply 13581 notifies the raw monitor 13582 <p/> 13583 This event is always sent as a matched pair with 13584 <eventlink id="GarbageCollectionStart"/> (assuming both events are enabled). 13585 <issue> 13586 The most important use of this event is to provide timing information, 13587 and thus additional information is not required. However, 13588 information about the collection which is "free" should be included - 13589 what that information is needs to be determined. 13590 </issue> 13591 </description> 13592 <origin>new</origin> 13593 <capabilities> 13594 <required id="can_generate_garbage_collection_events"></required> 13595 </capabilities> 13596 <parameters> 13597 </parameters> 13598 </event> 13599 13600 <elide> 13601 <event label="Verbose Output" phase="any" 13602 id="VerboseOutput" const="JVMTI_EVENT_VERBOSE_OUTPUT" num="85"> 13603 <description> 13604 Send verbose messages as strings. 13605 <issue> 13606 This format is extremely fragile, as it can change with each 13607 platform, collector and version. Alternatives include: 13608 <ul> 13609 <li>building off Java programming language M and M APIs</li> 13610 <li>XML</li> 13611 <li>key/value pairs</li> 13612 <li>removing it</li> 13613 </ul> 13614 </issue> 13615 <issue> 13616 Though this seemed trivial to implement. 13617 In the RI it appears this will be quite complex. 13618 </issue> 13619 </description> 13620 <origin>new</origin> 13621 <capabilities> 13622 </capabilities> 13623 <parameters> 13624 <param id="flag"> 13625 <enum>jvmtiVerboseFlag</enum> 13626 <description> 13627 Which verbose output is being sent. 13628 </description> 13629 </param> 13630 <param id="message"> 13631 <vmbuf><char/></vmbuf> 13632 <description> 13633 Message text, encoded as a 13634 <internallink id="mUTF">modified UTF-8</internallink> string. 13635 </description> 13636 </param> 13637 </parameters> 13638 </event> 13639 </elide> 13640 13641</eventsection> 13642 13643<datasection> 13644 <intro> 13645 <jvmti/> extends the data types defined by JNI. 13646 </intro> 13647 <basetypes id="jniTypes" label="JNI Types Used in the JVM Tool Interface"> 13648 <basetype id="jboolean"> 13649 <description> 13650 Holds a Java programming language <code>boolean</code>. 13651 Unsigned 8 bits. 13652 </description> 13653 </basetype> 13654 <basetype id="jchar"> 13655 <description> 13656 Holds a Java programming language <code>char</code>. 13657 Unsigned 16 bits. 13658 </description> 13659 </basetype> 13660 <basetype id="jint"> 13661 <description> 13662 Holds a Java programming language <code>int</code>. 13663 Signed 32 bits. 13664 </description> 13665 </basetype> 13666 <basetype id="jlong"> 13667 <description> 13668 Holds a Java programming language <code>long</code>. 13669 Signed 64 bits. 13670 </description> 13671 </basetype> 13672 <basetype id="jfloat"> 13673 <description> 13674 Holds a Java programming language <code>float</code>. 13675 32 bits. 13676 </description> 13677 </basetype> 13678 <basetype id="jdouble"> 13679 <description> 13680 Holds a Java programming language <code>double</code>. 13681 64 bits. 13682 </description> 13683 </basetype> 13684 <basetype id="jobject"> 13685 <description> 13686 Holds a Java programming language object. 13687 </description> 13688 </basetype> 13689 <basetype id="jclass"> 13690 <description> 13691 Holds a Java programming language class. 13692 </description> 13693 </basetype> 13694 <basetype id="jvalue"> 13695 <description> 13696 Is a union of all primitive types and <code>jobject</code>. Thus, holds any Java 13697 programming language value. 13698 </description> 13699 </basetype> 13700 <basetype id="jfieldID"> 13701 <description> 13702 Identifies a Java programming language field. 13703 <code>jfieldID</code>s returned by <jvmti/> functions and events may be 13704 safely stored. 13705 </description> 13706 </basetype> 13707 <basetype id="jmethodID"> 13708 <description> 13709 Identifies a Java programming language method, initializer, or constructor. 13710 <code>jmethodID</code>s returned by <jvmti/> functions and events may be 13711 safely stored. However, if the class is unloaded, they become invalid 13712 and must not be used. 13713 </description> 13714 </basetype> 13715 <basetype id="JNIEnv"> 13716 <description> 13717 Pointer to the JNI function table. Pointer to this (<code>JNIEnv *</code>) 13718 is a JNI environment. 13719 </description> 13720 </basetype> 13721 </basetypes> 13722 13723 <basetypes id="jvmtiTypes" label="JVM Tool Interface Base Types"> 13724 <basetype id="jvmtiEnv"> 13725 <description> 13726 The <jvmti/> <internallink id="environments">environment</internallink> pointer. 13727 See the <internallink id="FunctionSection">Function Section</internallink>. 13728 <code>jvmtiEnv</code> points to the 13729 <internallink id="FunctionTable">function table</internallink> pointer. 13730 </description> 13731 </basetype> 13732 <basetype id="jthread"> 13733 <definition>typedef jobject jthread;</definition> 13734 <description> 13735 Subtype of <datalink id="jobject"></datalink> that holds a thread. 13736 </description> 13737 </basetype> 13738 <basetype id="jthreadGroup"> 13739 <definition>typedef jobject jthreadGroup;</definition> 13740 <description> 13741 Subtype of <datalink id="jobject"></datalink> that holds a thread group. 13742 </description> 13743 </basetype> 13744 <basetype id="jlocation"> 13745 <definition>typedef jlong jlocation;</definition> 13746 <description> 13747 A 64 bit value, representing a monotonically increasing 13748 executable position within a method. 13749 <code>-1</code> indicates a native method. 13750 See <functionlink id="GetJLocationFormat"></functionlink> for the format on a 13751 given VM. 13752 </description> 13753 </basetype> 13754 <basetype id="jrawMonitorID"> 13755 <definition>struct _jrawMonitorID; 13756typedef struct _jrawMonitorID *jrawMonitorID;</definition> 13757 <description> 13758 A raw monitor. 13759 </description> 13760 </basetype> 13761 <basetype id="jvmtiError"> 13762 <description> 13763 Holds an error return code. 13764 See the <internallink id="ErrorSection">Error section</internallink> for possible values. 13765 <example> 13766typedef enum { 13767 JVMTI_ERROR_NONE = 0, 13768 JVMTI_ERROR_INVALID_THREAD = 10, 13769 ... 13770} jvmtiError; 13771</example> 13772 </description> 13773 </basetype> 13774 <basetype id="jvmtiEvent"> 13775 <description> 13776 An identifier for an event type. 13777 See the <internallink id="EventSection">Event section</internallink> for possible values. 13778 It is guaranteed that future versions of this specification will 13779 never assign zero as an event type identifier. 13780<example> 13781typedef enum { 13782 JVMTI_EVENT_SINGLE_STEP = 1, 13783 JVMTI_EVENT_BREAKPOINT = 2, 13784 ... 13785} jvmtiEvent; 13786</example> 13787 </description> 13788 </basetype> 13789 <basetype id="jvmtiEventCallbacks"> 13790 <description> 13791 The callbacks used for events. 13792<example> 13793typedef struct { 13794 jvmtiEventVMInit VMInit; 13795 jvmtiEventVMDeath VMDeath; 13796 ... 13797} jvmtiEventCallbacks; 13798</example> 13799 See <internallink id="jvmtiEventCallbacks">event callbacks</internallink> 13800 for the complete structure. 13801 <p/> 13802 Where, for example, the VM initialization callback is defined: 13803<example> 13804typedef void (JNICALL *jvmtiEventVMInit) 13805 (jvmtiEnv *jvmti_env, 13806 JNIEnv* jni_env, 13807 jthread thread); 13808</example> 13809 See the individual events for the callback function definition. 13810 </description> 13811 </basetype> 13812 <basetype id="jniNativeInterface"> 13813 <definition>typedef struct JNINativeInterface_ jniNativeInterface;</definition> 13814 <description> 13815 Typedef for the JNI function table <code>JNINativeInterface</code> 13816 defined in the 13817 <externallink id="jni/functions.html#interface-function-table"> 13818 JNI Specification</externallink>. 13819 The JNI reference implementation defines this with an underscore. 13820 </description> 13821 </basetype> 13822 </basetypes> 13823 13824</datasection> 13825 13826<issuessection label="Issues"> 13827 <intro id="suspendRequired" label="Resolved Issue: Suspend - Required or Automatic"> 13828 JVMDI requires that the agent suspend threads before calling 13829 certain sensitive functions. JVMPI requires garbage collection to be 13830 disabled before calling certain sensitive functions. 13831 It was suggested that rather than have this requirement, that 13832 VM place itself in a suitable state before performing an 13833 operation. This makes considerable sense since each VM 13834 knows its requirements and can most easily arrange a 13835 safe state. 13836 <p/> 13837 The ability to externally suspend/resume threads will, of 13838 course, remain. The ability to enable/disable garbage collection will not. 13839 <p/> 13840 This issue is resolved--suspend will not 13841 be required. The spec has been updated to reflect this. 13842 </intro> 13843 13844 <intro id="stackSampling" label="Resolved Issue: Call Stack Sampling"> 13845 There are a variety of approaches to sampling call stacks. 13846 The biggest bifurcation is between VM controlled and agent 13847 controlled. 13848 <p/> 13849 This issue is resolved--agent controlled 13850 sampling will be the approach. 13851 </intro> 13852 13853 <intro id="threadRepresentation" label="Resolved Issue: Thread Representation"> 13854 JVMDI represents threads as jthread. JVMPI primarily 13855 uses JNIEnv* to represent threads. 13856 <p/> 13857 The Expert Group has chosen jthread as the representation 13858 for threads in <jvmti/>. 13859 JNIEnv* is sent by 13860 events since it is needed to JNI functions. JNIEnv, per the 13861 JNI spec, are not supposed to be used outside their thread. 13862 </intro> 13863 13864 <intro id="design" label="Resolved Issue: Method Representation"> 13865 The JNI spec allows an implementation to depend on jclass/jmethodID 13866 pairs, rather than simply a jmethodID, to reference a method. 13867 JVMDI, for consistency, choose the same representation. 13868 JVMPI, however, specifies that a jmethodID alone maps to a 13869 method. Both of the Sun <tm>J2SE</tm> virtual machines (Classic and <tm>HotSpot</tm>) store 13870 pointers in jmethodIDs, and as a result, a jmethodID is sufficient. 13871 In fact, any JVM implementation that supports JVMPI must have 13872 such a representation. 13873 <jvmti/> will use jmethodID as a unique representation of a method 13874 (no jclass is used). 13875 There should be efficiency gains, particularly in 13876 functionality like stack dumping, to this representation. 13877 <p/> 13878 Note that fields were not used in JVMPI and that the access profile 13879 of fields differs from methods--for implementation efficiency 13880 reasons, a jclass/jfieldID pair will still be needed for field 13881 reference. 13882 </intro> 13883 13884 <intro id="localReferenceIssue" label="Resolved Issue: Local References"> 13885 Functions return local references. 13886 </intro> 13887 13888 <intro id="frameRep" label="Resolved Issue: Representation of frames"> 13889 In JVMDI, a frame ID is used to represent a frame. Problem with this 13890 is that a VM must track when a frame becomes invalid, a far better 13891 approach, and the one used in <jvmti/>, is to reference frames by depth. 13892 </intro> 13893 13894 <intro id="requiredCapabilities" label="Issue: Required Capabilities"> 13895 Currently, having a required capabilities means that the functionality 13896 is optional. Capabilities are useful even for required functionality 13897 since they can inform the VM is needed set-up. Thus, there should be 13898 a set of capabilities that a conformant implementation must provide 13899 (if requested during Agent_OnLoad). 13900 </intro> 13901 13902 <intro id="taghint" label="Proposal: add tag hint function"> 13903 A hint of the percentage of objects that will be tagged would 13904 help the VM pick a good implementation. 13905 </intro> 13906 13907 <intro id="moreMonitorQueries" label="Request: More Monitor Quires"> 13908 How difficult or easy would be to extend the monitor_info category to include 13909 <pre> 13910 - current number of monitors 13911 - enumeration of monitors 13912 - enumeration of threads waiting on a given monitor 13913 </pre> 13914 The reason for my question is the fact that current get_monitor_info support 13915 requires the agent to specify a given thread to get the info which is probably 13916 OK in the profiling/debugging space, while in the monitoring space the agent 13917 could be watching the monitor list and then decide which thread to ask for 13918 the info. You might ask why is this important for monitoring .... I think it 13919 can aid in the detection/prediction of application contention caused by hot-locks. 13920 </intro> 13921</issuessection> 13922 13923<changehistory id="ChangeHistory" update="09/05/07"> 13924 <intro> 13925 The <jvmti/> specification is an evolving document with major, minor, 13926 and micro version numbers. 13927 A released version of the specification is uniquely identified 13928 by its major and minor version. 13929 The functions, events, and capabilities in this specification 13930 indicate a "Since" value which is the major and minor version in 13931 which it was introduced. 13932 The version of the specification implemented by the VM can 13933 be retrieved at runtime with the <functionlink id="GetVersionNumber"/> 13934 function. 13935 </intro> 13936 <change date="14 Nov 2002"> 13937 Converted to XML document. 13938 </change> 13939 <change date="14 Nov 2002"> 13940 Elided heap dump functions (for now) since what was there 13941 was wrong. 13942 </change> 13943 <change date="18 Nov 2002"> 13944 Added detail throughout. 13945 </change> 13946 <change date="18 Nov 2002"> 13947 Changed JVMTI_THREAD_STATUS_RUNNING to JVMTI_THREAD_STATUS_RUNNABLE. 13948 </change> 13949 <change date="19 Nov 2002"> 13950 Added AsyncGetStackTrace. 13951 </change> 13952 <change date="19 Nov 2002"> 13953 Added jframeID return to GetStackTrace. 13954 </change> 13955 <change date="19 Nov 2002"> 13956 Elided GetCurrentFrame and GetCallingFrame functions (for now) since what was there 13957 since they are redundant with GetStackTrace. 13958 </change> 13959 <change date="19 Nov 2002"> 13960 Elided ClearAllBreakpoints since it has always been redundant. 13961 </change> 13962 <change date="19 Nov 2002"> 13963 Added GetSystemProperties. 13964 </change> 13965 <change date="19 Nov 2002"> 13966 Changed the thread local storage functions to use jthread. 13967 </change> 13968 <change date="20 Nov 2002"> 13969 Added GetJLocationFormat. 13970 </change> 13971 <change date="22 Nov 2002"> 13972 Added events and introductory text. 13973 </change> 13974 <change date="22 Nov 2002"> 13975 Cross reference type and constant definitions. 13976 </change> 13977 <change date="24 Nov 2002"> 13978 Added DTD. 13979 </change> 13980 <change date="24 Nov 2002"> 13981 Added capabilities function section. 13982 </change> 13983 <change date="29 Nov 2002"> 13984 Assign capabilities to each function and event. 13985 </change> 13986 <change date="29 Nov 2002"> 13987 Add <internallink id="jniIntercept">JNI interception functions</internallink>. 13988 </change> 13989 <change date="30 Nov 2002"> 13990 Auto generate SetEventNotificationMode capabilities. 13991 </change> 13992 <change date="30 Nov 2002"> 13993 Add <eventlink id="VMObjectAlloc"></eventlink> event. 13994 </change> 13995 <change date="30 Nov 2002"> 13996 Add <eventlink id="DynamicCodeGenerated"></eventlink> event. 13997 </change> 13998 <change date="30 Nov 2002"> 13999 Add const to declarations. 14000 </change> 14001 <change date="30 Nov 2002"> 14002 Change method exit and frame pop to send on exception. 14003 </change> 14004 <change date="1 Dec 2002"> 14005 Add ForceGarbageCollection. 14006 </change> 14007 <change date="2 Dec 2002"> 14008 Redo Xrun section; clarify GetStackTrace and add example; 14009 Fix width problems; use "agent" consistently. 14010 </change> 14011 <change date="8 Dec 2002"> 14012 Remove previous start-up intro. 14013 Add <internallink id="environments"><jvmti/> Environments</internallink> 14014 section. 14015 </change> 14016 <change date="8 Dec 2002"> 14017 Add <functionlink id="DisposeEnvironment"></functionlink>. 14018 </change> 14019 <change date="9 Dec 2002"> 14020 Numerous minor updates. 14021 </change> 14022 <change date="15 Dec 2002"> 14023 Add heap profiling functions added: 14024 get/set annotation, iterate live objects/heap. 14025 Add heap profiling functions place holder added: 14026 heap roots. 14027 Heap profiling event added: object free. 14028 Heap profiling event redesigned: vm object allocation. 14029 Heap profiling event placeholders added: garbage collection start/finish. 14030 Native method bind event added. 14031 </change> 14032 <change date="19 Dec 2002"> 14033 Revamp suspend/resume functions. 14034 Add origin information with jvmdi tag. 14035 Misc fixes. 14036 </change> 14037 <change date="24 Dec 2002"> 14038 Add semantics to types. 14039 </change> 14040 <change date="27 Dec 2002"> 14041 Add local reference section. 14042 Autogenerate parameter descriptions from types. 14043 </change> 14044 <change date="28 Dec 2002"> 14045 Document that RunAgentThread sends threadStart. 14046 </change> 14047 <change date="29 Dec 2002"> 14048 Remove redundant local ref and dealloc warning. 14049 Convert GetRawMonitorName to allocated buffer. 14050 Add GenerateEvents. 14051 </change> 14052 <change date="30 Dec 2002"> 14053 Make raw monitors a type and rename to "jrawMonitorID". 14054 </change> 14055 <change date="1 Jan 2003"> 14056 Include origin information. 14057 Clean-up JVMDI issue references. 14058 Remove Deallocate warnings which are now automatically generated. 14059 </change> 14060 <change date="2 Jan 2003"> 14061 Fix representation issues for jthread. 14062 </change> 14063 <change date="3 Jan 2003"> 14064 Make capabilities buffered out to 64 bits - and do it automatically. 14065 </change> 14066 <change date="4 Jan 2003"> 14067 Make constants which are enumeration into enum types. 14068 Parameters now of enum type. 14069 Clean-up and index type section. 14070 Replace remaining datadef entities with callback. 14071 </change> 14072 <change date="7 Jan 2003"> 14073 Correct GenerateEvents description. 14074 More internal semantics work. 14075 </change> 14076 <change date="9 Jan 2003"> 14077 Replace previous GetSystemProperties with two functions 14078 which use allocated information instead fixed. 14079 Add SetSystemProperty. 14080 More internal semantics work. 14081 </change> 14082 <change date="12 Jan 2003"> 14083 Add varargs to end of SetEventNotificationMode. 14084 </change> 14085 <change date="20 Jan 2003"> 14086 Finish fixing spec to reflect that alloc sizes are jlong. 14087 </change> 14088 <change date="22 Jan 2003"> 14089 Allow NULL as RunAgentThread arg. 14090 </change> 14091 <change date="22 Jan 2003"> 14092 Fixed names to standardized naming convention 14093 Removed AsyncGetStackTrace. 14094 </change> 14095 <change date="29 Jan 2003"> 14096 Since we are using jthread, removed GetThread. 14097 </change> 14098 <change date="31 Jan 2003"> 14099 Change GetFieldName to allow NULLs like GetMethodName. 14100 </change> 14101 <change date="29 Feb 2003" version="v40"> 14102 Rewrite the introductory text, adding sections on 14103 start-up, environments and bytecode instrumentation. 14104 Change the command line arguments per EG discussions. 14105 Add an introduction to the capabilities section. 14106 Add the extension mechanism category and functions. 14107 Mark for deletion, but clarified anyhow, SuspendAllThreads. 14108 Rename IterateOverLiveObjects to IterateOverReachableObjects and 14109 change the text accordingly. 14110 Clarify IterateOverHeap. 14111 Clarify CompiledMethodLoad. 14112 Discuss prerequisite state for Calling Functions. 14113 Clarify SetAllocationHooks. 14114 Added issues ("To be resolved:") through-out. 14115 And so on... 14116 </change> 14117 <change date="6 Mar 2003" version="v41"> 14118 Remove struct from the call to GetOwnedMonitorInfo. 14119 Automatically generate most error documentation, remove 14120 (rather broken) hand written error doc. 14121 Better describe capability use (empty initial set). 14122 Add min value to jint params. 14123 Remove the capability can_access_thread_local_storage. 14124 Rename error JVMTI_ERROR_NOT_IMPLEMENTED to JVMTI_ERROR_MUST_POSSESS_CAPABILITY; 14125 same for *NOT_IMPLEMENTED. 14126 Description fixes. 14127 </change> 14128 <change date="8 Mar 2003" version="v42"> 14129 Rename GetClassSignature to GetClassName. 14130 Rename IterateOverClassObjects to IterateOverInstancesOfClass. 14131 Remove GetMaxStack (operand stack isn't used in <jvmti/>). 14132 Description fixes: define launch-time, remove native frame pop 14133 from PopFrame, and assorted clarifications. 14134 </change> 14135 <change date="8 Mar 2003" version="v43"> 14136 Fix minor editing problem. 14137 </change> 14138 <change date="10 Mar 2003" version="v44"> 14139 Add phase information. 14140 Remap (compact) event numbers. 14141 </change> 14142 <change date="11 Mar 2003" version="v45"> 14143 More phase information - allow "any". 14144 Elide raw monitor queries and events. 14145 Minor description fixes. 14146 </change> 14147 <change date="12 Mar 2003" version="v46"> 14148 Add GetPhase. 14149 Use "phase" through document. 14150 Elide GetRawMonitorName. 14151 Elide GetObjectMonitors. 14152 </change> 14153 <change date="12 Mar 2003" version="v47"> 14154 Fixes from link, XML, and spell checking. 14155 Auto-generate the callback structure. 14156 </change> 14157 <change date="13 Mar 2003" version="v48"> 14158 One character XML fix. 14159 </change> 14160 <change date="13 Mar 2003" version="v49"> 14161 Change function parameter names to be consistent with 14162 event parameters (fooBarBaz becomes foo_bar_baz). 14163 </change> 14164 <change date="14 Mar 2003" version="v50"> 14165 Fix broken link. Fix thread markers. 14166 </change> 14167 <change date="14 Mar 2003" version="v51"> 14168 Change constants so they are under 128 to workaround 14169 compiler problems. 14170 </change> 14171 <change date="23 Mar 2003" version="v52"> 14172 Overhaul capabilities. Separate GetStackTrace into 14173 GetStackTrace and GetStackFrames. 14174 </change> 14175 <change date="8 Apr 2003" version="v54"> 14176 Use depth instead of jframeID to reference frames. 14177 Remove the now irrelevant GetCurrentFrame, GetCallerFrame and GetStackFrames. 14178 Remove frame arg from events. 14179 </change> 14180 <change date="9 Apr 2003" version="v55"> 14181 Remove GetObjectWithAnnotation since tests show bufferred approach more efficient. 14182 Add missing annotation_count to GetObjectsWithAnnotations 14183 </change> 14184 <change date="10 Apr 2003" version="v56"> 14185 Remove confusing parenthetical statement in GetObjectsWithAnnotations 14186 </change> 14187 <change date="13 Apr 2003" version="v58"> 14188 Replace jclass/jmethodID representation of method with simply jmethodID; 14189 Pass JvmtiEnv* as first arg of every event; remove JNIEnv* where inappropriate. 14190 Replace can_access_frames with can_access_local_variables; remove from purely stack access. 14191 Use can_get_synthetic_attribute; fix description. 14192 Clarify that zero length arrays must be deallocated. 14193 Clarify RelinquishCapabilities. 14194 Generalize JVMTI_ERROR_VM_DEAD to JVMTI_ERROR_WRONG_PHASE. 14195 </change> 14196 <change date="27 Apr 2003" version="v59"> 14197 Remove lingering indirect references to OBSOLETE_METHOD_ID. 14198 </change> 14199 <change date="4 May 2003" version="v60"> 14200 Allow DestroyRawMonitor during OnLoad. 14201 </change> 14202 <change date="7 May 2003" version="v61"> 14203 Added not monitor owner error return to DestroyRawMonitor. 14204 </change> 14205 <change date="13 May 2003" version="v62"> 14206 Clarify semantics of raw monitors. 14207 Change flags on <code>GetThreadStatus</code>. 14208 <code>GetClassLoader</code> return NULL for the bootstrap class loader. 14209 Add <code>GetClassName</code> issue. 14210 Define local variable signature. 14211 Disallow zero in annotations array of <code>GetObjectsWithAnnotations</code>. 14212 Remove over specification in <code>GetObjectsWithAnnotations</code>. 14213 Elide <code>SetAllocationHooks</code>. 14214 Elide <code>SuspendAllThreads</code>. 14215 </change> 14216 <change date="14 May 2003" version="v63"> 14217 Define the data type <code>jvmtiEventCallbacks</code>. 14218 Zero length allocations return NULL. 14219 Keep SetAllocationHooks in JVMDI, but remove from <jvmti/>. 14220 Add JVMTI_THREAD_STATUS_FLAG_INTERRUPTED. 14221 </change> 14222 <change date="15 May 2003" version="v64"> 14223 Better wording, per review. 14224 </change> 14225 <change date="15 May 2003" version="v65"> 14226 First Alpha. 14227 Make jmethodID and jfieldID unique, jclass not used. 14228 </change> 14229 <change date="27 May 2003" version="v66"> 14230 Fix minor XSLT errors. 14231 </change> 14232 <change date="13 June 2003" version="v67"> 14233 Undo making jfieldID unique (jmethodID still is). 14234 </change> 14235 <change date="17 June 2003" version="v68"> 14236 Changes per June 11th Expert Group meeting -- 14237 Overhaul Heap functionality: single callback, 14238 remove GetHeapRoots, add reachable iterators, 14239 and rename "annotation" to "tag". 14240 NULL thread parameter on most functions is current 14241 thread. 14242 Add timers. 14243 Remove ForceExit. 14244 Add GetEnvironmentLocalStorage. 14245 Add verbose flag and event. 14246 Add AddToBootstrapClassLoaderSearch. 14247 Update ClassFileLoadHook. 14248 </change> 14249 <change date="18 June 2003" version="v69"> 14250 Clean up issues sections. 14251 Rename GetClassName back to GetClassSignature and 14252 fix description. 14253 Add generic signature to GetClassSignature, 14254 GetFieldSignature, GetMethodSignature, and 14255 GetLocalVariableTable. 14256 Elide EstimateCostOfCapabilities. 14257 Clarify that the system property functions operate 14258 on the VM view of system properties. 14259 Clarify Agent_OnLoad. 14260 Remove "const" from JNIEnv* in events. 14261 Add metadata accessors. 14262 </change> 14263 <change date="18 June 2003" version="v70"> 14264 Add start_depth to GetStackTrace. 14265 Move system properties to a new category. 14266 Add GetObjectSize. 14267 Remove "X" from command line flags. 14268 XML, HTML, and spell check corrections. 14269 </change> 14270 <change date="19 June 2003" version="v71"> 14271 Fix JVMTI_HEAP_ROOT_THREAD to be 6. 14272 Make each synopsis match the function name. 14273 Fix unclear wording. 14274 </change> 14275 <change date="26 June 2003" version="v72"> 14276 SetThreadLocalStorage and SetEnvironmentLocalStorage should allow value 14277 to be set to NULL. 14278 NotifyFramePop, GetFrameLocationm and all the local variable operations 14279 needed to have their wording about frames fixed. 14280 Grammar and clarity need to be fixed throughout. 14281 Capitalization and puntuation need to be consistent. 14282 Need micro version number and masks for accessing major, minor, and micro. 14283 The error code lists should indicate which must be returned by 14284 an implementation. 14285 The command line properties should be visible in the properties functions. 14286 Disallow popping from the current thread. 14287 Allow implementations to return opaque frame error when they cannot pop. 14288 The NativeMethodBind event should be sent during any phase. 14289 The DynamicCodeGenerated event should be sent during any phase. 14290 The following functions should be allowed to operate before VMInit: 14291 Set/GetEnvironmentLocalStorage 14292 GetMethodDeclaringClass 14293 GetClassSignature 14294 GetClassModifiers 14295 IsInterface 14296 IsArrayClass 14297 GetMethodName 14298 GetMethodModifiers 14299 GetMaxLocals 14300 GetArgumentsSize 14301 GetLineNumberTable 14302 GetMethodLocation 14303 IsMethodNative 14304 IsMethodSynthetic. 14305 Other changes (to XSL): 14306 Argument description should show asterisk after not before pointers. 14307 NotifyFramePop, GetFrameLocationm and all the local variable operations 14308 should hsve the NO_MORE_FRAMES error added. 14309 Not alive threads should have a different error return than invalid thread. 14310 </change> 14311 <change date="7 July 2003" version="v73"> 14312 VerboseOutput event was missing message parameter. 14313 Minor fix-ups. 14314 </change> 14315 <change date="14 July 2003" version="v74"> 14316 Technical Publications Department corrections. 14317 Allow thread and environment local storage to be set to NULL. 14318 </change> 14319 <change date="23 July 2003" version="v75"> 14320 Use new Agent_OnLoad rather than overloaded JVM_OnLoad. 14321 Add JNICALL to callbacks (XSL). 14322 Document JNICALL requirement for both events and callbacks (XSL). 14323 Restrict RedefineClasses to methods and attributes. 14324 Elide the VerboseOutput event. 14325 VMObjectAlloc: restrict when event is sent and remove method parameter. 14326 Finish loose ends from Tech Pubs edit. 14327 </change> 14328 <change date="24 July 2003" version="v76"> 14329 Change ClassFileLoadHook event to send the class instead of a boolean of redefine. 14330 </change> 14331 <change date="24 July 2003" version="v77"> 14332 XML fixes. 14333 Minor text clarifications and corrections. 14334 </change> 14335 <change date="24 July 2003" version="v78"> 14336 Remove GetExceptionHandlerTable and GetThrownExceptions from <jvmti/>. 14337 Clarify that stack frames are JVM Spec frames. 14338 Split can_get_source_info into can_get_source_file_name, can_get_line_numbers, 14339 and can_get_source_debug_extension. 14340 PopFrame cannot have a native calling method. 14341 Removed incorrect statement in GetClassloaderClasses 14342 (see <vmspec chapter="4.4"/>). 14343 </change> 14344 <change date="24 July 2003" version="v79"> 14345 XML and text fixes. 14346 Move stack frame description into Stack Frame category. 14347 </change> 14348 <change date="26 July 2003" version="v80"> 14349 Allow NULL (means bootstrap loader) for GetClassloaderClasses. 14350 Add new heap reference kinds for references from classes. 14351 Add timer information struct and query functions. 14352 Add AvailableProcessors. 14353 Rename GetOtherThreadCpuTime to GetThreadCpuTime. 14354 Explicitly add JVMTI_ERROR_INVALID_THREAD and JVMTI_ERROR_THREAD_NOT_ALIVE 14355 to SetEventNotification mode. 14356 Add initial thread to the VM_INIT event. 14357 Remove platform assumptions from AddToBootstrapClassLoaderSearch. 14358 </change> 14359 <change date="26 July 2003" version="v81"> 14360 Grammar and clarity changes per review. 14361 </change> 14362 <change date="27 July 2003" version="v82"> 14363 More grammar and clarity changes per review. 14364 Add Agent_OnUnload. 14365 </change> 14366 <change date="28 July 2003" version="v83"> 14367 Change return type of Agent_OnUnload to void. 14368 </change> 14369 <change date="28 July 2003" version="v84"> 14370 Rename JVMTI_REFERENCE_ARRAY to JVMTI_REFERENCE_ARRAY_ELEMENT. 14371 </change> 14372 <change date="28 July 2003" version="v85"> 14373 Steal java.lang.Runtime.availableProcessors() wording for 14374 AvailableProcessors(). 14375 Guarantee that zero will never be an event ID. 14376 Remove some issues which are no longer issues. 14377 Per review, rename and more completely document the timer 14378 information functions. 14379 </change> 14380 <change date="29 July 2003" version="v86"> 14381 Non-spec visible change to XML controlled implementation: 14382 SetThreadLocalStorage must run in VM mode. 14383 </change> 14384 <change date="5 August 2003" version="0.1.87"> 14385 Add GetErrorName. 14386 Add varargs warning to jvmtiExtensionEvent. 14387 Remove "const" on the jvmtiEnv* of jvmtiExtensionEvent. 14388 Remove unused can_get_exception_info capability. 14389 Pass jvmtiEnv* and JNIEnv* to the jvmtiStartFunction. 14390 Fix jvmtiExtensionFunctionInfo.func declared type. 14391 Extension function returns error code. 14392 Use new version numbering. 14393 </change> 14394 <change date="5 August 2003" version="0.2.88"> 14395 Remove the ClassUnload event. 14396 </change> 14397 <change date="8 August 2003" version="0.2.89"> 14398 Heap reference iterator callbacks return an enum that 14399 allows outgoing object references to be ignored. 14400 Allow JNIEnv as a param type to extension events/functions. 14401 </change> 14402 <change date="15 August 2003" version="0.2.90"> 14403 Fix a typo. 14404 </change> 14405 <change date="2 September 2003" version="0.2.91"> 14406 Remove all metadata functions: GetClassMetadata, 14407 GetFieldMetadata, and GetMethodMetadata. 14408 </change> 14409 <change date="1 October 2003" version="0.2.92"> 14410 Mark the functions Allocate. Deallocate, RawMonitor*, 14411 SetEnvironmentLocalStorage, and GetEnvironmentLocalStorage 14412 as safe for use in heap callbacks and GC events. 14413 </change> 14414 <change date="24 November 2003" version="0.2.93"> 14415 Add pass through opaque user data pointer to heap iterate 14416 functions and callbacks. 14417 In the CompiledMethodUnload event, send the code address. 14418 Add GarbageCollectionOccurred event. 14419 Add constant pool reference kind. 14420 Mark the functions CreateRawMonitor and DestroyRawMonitor 14421 as safe for use in heap callbacks and GC events. 14422 Clarify: VMDeath, GetCurrentThreadCpuTimerInfo, 14423 GetThreadCpuTimerInfo, IterateOverReachableObjects, 14424 IterateOverObjectsReachableFromObject, GetTime and 14425 JVMTI_ERROR_NULL_POINTER. 14426 Add missing errors to: GenerateEvents and 14427 AddToBootstrapClassLoaderSearch. 14428 Fix description of ClassFileLoadHook name parameter. 14429 In heap callbacks and GC/ObjectFree events, specify 14430 that only explicitly allowed functions can be called. 14431 Allow GetCurrentThreadCpuTimerInfo, GetCurrentThreadCpuTime, 14432 GetTimerInfo, and GetTime during callback. 14433 Allow calling SetTag/GetTag during the onload phase. 14434 SetEventNotificationMode, add: error attempted inappropriate 14435 thread level control. 14436 Remove jvmtiExceptionHandlerEntry. 14437 Fix handling of native methods on the stack -- 14438 location_ptr param of GetFrameLocation, remove 14439 JVMTI_ERROR_OPAQUE_FRAME from GetFrameLocation, 14440 jvmtiFrameInfo.location, and jlocation. 14441 Remove typo (from JVMPI) implying that the MonitorWaited 14442 event is sent on sleep. 14443 </change> 14444 <change date="25 November 2003" version="0.2.94"> 14445 Clarifications and typos. 14446 </change> 14447 <change date="3 December 2003" version="0.2.95"> 14448 Allow NULL user_data in heap iterators. 14449 </change> 14450 <change date="28 January 2004" version="0.2.97"> 14451 Add GetThreadState, deprecate GetThreadStatus. 14452 </change> 14453 <change date="29 January 2004" version="0.2.98"> 14454 INVALID_SLOT and TYPE_MISMATCH errors should be optional. 14455 </change> 14456 <change date="12 February 2004" version="0.2.102"> 14457 Remove MonitorContendedExit. 14458 Added JNIEnv parameter to VMObjectAlloc. 14459 Clarified definition of class_tag and referrer_index 14460 parameters to heap callbacks. 14461 </change> 14462 <change date="16 Febuary 2004" version="0.2.103"> 14463 Document JAVA_TOOL_OPTIONS. 14464 </change> 14465 <change date="17 Febuary 2004" version="0.2.105"> 14466 Divide start phase into primordial and start. 14467 Add VMStart event 14468 Change phase associations of functions and events. 14469 </change> 14470 <change date="18 Febuary 2004" version="0.3.6"> 14471 Elide deprecated GetThreadStatus. 14472 Bump minor version, subtract 100 from micro version 14473 </change> 14474 <change date="18 Febuary 2004" version="0.3.7"> 14475 Document that timer nanosecond values are unsigned. 14476 Clarify text having to do with native methods. 14477 </change> 14478 <change date="19 Febuary 2004" version="0.3.8"> 14479 Fix typos. 14480 Remove elided deprecated GetThreadStatus. 14481 </change> 14482 <change date="23 Febuary 2004" version="0.3.9"> 14483 Require NotifyFramePop to act on suspended threads. 14484 </change> 14485 <change date="24 Febuary 2004" version="0.3.10"> 14486 Add capabilities 14487 (<internallink id="jvmtiCapabilities.can_redefine_any_class" 14488 ><code>can_redefine_any_class</code></internallink> 14489 and 14490 <internallink id="jvmtiCapabilities.can_generate_all_class_hook_events" 14491 ><code>can_generate_all_class_hook_events</code></internallink>) 14492 and an error (<errorlink id="JVMTI_ERROR_UNMODIFIABLE_CLASS"></errorlink>) 14493 which allow some classes to be unmodifiable. 14494 </change> 14495 <change date="28 Febuary 2004" version="0.3.11"> 14496 Add JVMTI_ERROR_MUST_POSSESS_CAPABILITY to SetEventNotificationMode. 14497 </change> 14498 <change date="8 March 2004" version="0.3.12"> 14499 Clarified CompiledMethodUnload so that it is clear the event 14500 may be posted after the class has been unloaded. 14501 </change> 14502 <change date="5 March 2004" version="0.3.13"> 14503 Change the size parameter of VMObjectAlloc to jlong to match GetObjectSize. 14504 </change> 14505 <change date="13 March 2004" version="0.3.14"> 14506 Added guideline for the use of the JNI FindClass function in event 14507 callback functions. 14508 </change> 14509 <change date="15 March 2004" version="0.3.15"> 14510 Add GetAllStackTraces and GetThreadListStackTraces. 14511 </change> 14512 <change date="19 March 2004" version="0.3.16"> 14513 ClassLoad and ClassPrepare events can be posted during start phase. 14514 </change> 14515 <change date="25 March 2004" version="0.3.17"> 14516 Add JVMTI_ERROR_NATIVE_METHOD to GetLineNumberTable, GetLocalVariableTable, 14517 GetMaxLocals, GetArgumentsSize, GetMethodLocation, GetBytecodes. 14518 </change> 14519 <change date="29 March 2004" version="0.3.18"> 14520 Return the timer kind in the timer information structure. 14521 </change> 14522 <change date="31 March 2004" version="0.3.19"> 14523 Spec clarifications: 14524 JVMTI_THREAD_STATE_IN_NATIVE might not include JNI or <jvmti/>. 14525 ForceGarbageCollection does not run finalizers. 14526 The context of the specification is the Java platform. 14527 Warn about early instrumentation. 14528 </change> 14529 <change date="1 April 2004" version="0.3.20"> 14530 Refinements to the above clarifications and 14531 Clarify that an error returned by Agent_OnLoad terminates the VM. 14532 </change> 14533 <change date="1 April 2004" version="0.3.21"> 14534 Array class creation does not generate a class load event. 14535 </change> 14536 <change date="7 April 2004" version="0.3.22"> 14537 Align thread state hierarchy more closely with java.lang.Thread.State. 14538 </change> 14539 <change date="12 April 2004" version="0.3.23"> 14540 Clarify the documentation of thread state. 14541 </change> 14542 <change date="19 April 2004" version="0.3.24"> 14543 Remove GarbageCollectionOccurred event -- can be done by agent. 14544 </change> 14545 <change date="22 April 2004" version="0.3.25"> 14546 Define "command-line option". 14547 </change> 14548 <change date="29 April 2004" version="0.3.26"> 14549 Describe the intended use of bytecode instrumentation. 14550 Fix description of extension event first parameter. 14551 </change> 14552 <change date="30 April 2004" version="0.3.27"> 14553 Clarification and typos. 14554 </change> 14555 <change date="18 May 2004" version="0.3.28"> 14556 Remove DataDumpRequest event. 14557 </change> 14558 <change date="18 May 2004" version="0.3.29"> 14559 Clarify RawMonitorWait with zero timeout. 14560 Clarify thread state after RunAgentThread. 14561 </change> 14562 <change date="24 May 2004" version="0.3.30"> 14563 Clean-up: fix bad/old links, etc. 14564 </change> 14565 <change date="30 May 2004" version="0.3.31"> 14566 Clarifications including: 14567 All character strings are modified UTF-8. 14568 Agent thread visibiity. 14569 Meaning of obsolete method version. 14570 Thread invoking heap callbacks, 14571 </change> 14572 <change date="1 June 2004" version="1.0.32"> 14573 Bump major.minor version numbers to "1.0". 14574 </change> 14575 <change date="2 June 2004" version="1.0.33"> 14576 Clarify interaction between ForceGarbageCollection 14577 and ObjectFree. 14578 </change> 14579 <change date="6 June 2004" version="1.0.34"> 14580 Restrict AddToBootstrapClassLoaderSearch and 14581 SetSystemProperty to the OnLoad phase only. 14582 </change> 14583 <change date="11 June 2004" version="1.0.35"> 14584 Fix typo in SetTag. 14585 </change> 14586 <change date="18 June 2004" version="1.0.36"> 14587 Fix trademarks. 14588 Add missing parameter in example GetThreadState usage. 14589 </change> 14590 <change date="4 August 2004" version="1.0.37"> 14591 Copyright updates. 14592 </change> 14593 <change date="5 November 2004" version="1.0.38"> 14594 Add missing function table layout. 14595 Add missing description of C++ member function format of functions. 14596 Clarify that name in CFLH can be NULL. 14597 Released as part of <tm>J2SE</tm> 5.0. 14598 </change> 14599 <change date="24 April 2005" version="1.1.47"> 14600 Bump major.minor version numbers to "1.1". 14601 Add ForceEarlyReturn* functions. 14602 Add GetOwnedMonitorStackDepthInfo function. 14603 Add GetCurrentThread function. 14604 Add "since" version marker. 14605 Add AddToSystemClassLoaderSearch. 14606 Allow AddToBootstrapClassLoaderSearch be used in live phase. 14607 Fix historic rubbish in the descriptions of the heap_object_callback 14608 parameter of IterateOverHeap and IterateOverInstancesOfClass functions; 14609 disallow NULL for this parameter. 14610 Clarify, correct and make consistent: wording about current thread, 14611 opaque frames and insufficient number of frames in PopFrame. 14612 Consistently use "current frame" rather than "topmost". 14613 Clarify the JVMTI_ERROR_TYPE_MISMATCH errors in GetLocal* and SetLocal* 14614 by making them compatible with those in ForceEarlyReturn*. 14615 Many other clarifications and wording clean ups. 14616 </change> 14617 <change date="25 April 2005" version="1.1.48"> 14618 Add GetConstantPool. 14619 Switch references to the first edition of the VM Spec, to the seconds edition. 14620 </change> 14621 <change date="26 April 2005" version="1.1.49"> 14622 Clarify minor/major version order in GetConstantPool. 14623 </change> 14624 <change date="26 April 2005" version="1.1.50"> 14625 Add SetNativeMethodPrefix and SetNativeMethodPrefixes. 14626 Reassign GetOwnedMonitorStackDepthInfo to position 153. 14627 Break out Class Loader Search in its own documentation category. 14628 Deal with overly long lines in XML source. 14629 </change> 14630 <change date="29 April 2005" version="1.1.51"> 14631 Allow agents be started in the live phase. 14632 Added paragraph about deploying agents. 14633 </change> 14634 <change date="30 April 2005" version="1.1.52"> 14635 Add specification description to SetNativeMethodPrefix(es). 14636 Better define the conditions on GetConstantPool. 14637 </change> 14638 <change date="30 April 2005" version="1.1.53"> 14639 Break out the GetClassVersionNumber function from GetConstantPool. 14640 Clean-up the references to the VM Spec. 14641 </change> 14642 <change date="1 May 2005" version="1.1.54"> 14643 Allow SetNativeMethodPrefix(es) in any phase. 14644 Add clarifications about the impact of redefinition on GetConstantPool. 14645 </change> 14646 <change date="2 May 2005" version="1.1.56"> 14647 Various clarifications to SetNativeMethodPrefix(es). 14648 </change> 14649 <change date="2 May 2005" version="1.1.57"> 14650 Add missing performance warning to the method entry event. 14651 </change> 14652 <change date="5 May 2005" version="1.1.58"> 14653 Remove internal JVMDI support. 14654 </change> 14655 <change date="8 May 2005" version="1.1.59"> 14656 Add <functionlink id="RetransformClasses"/>. 14657 Revamp the bytecode instrumentation documentation. 14658 Change <functionlink id="IsMethodObsolete"/> to no longer 14659 require the can_redefine_classes capability. 14660 </change> 14661 <change date="11 May 2005" version="1.1.63"> 14662 Clarifications for retransformation. 14663 </change> 14664 <change date="11 May 2005" version="1.1.64"> 14665 Clarifications for retransformation, per review. 14666 Lock "retransformation (in)capable" at class load enable time. 14667 </change> 14668 <change date="4 June 2005" version="1.1.67"> 14669 Add new heap functionity which supports reporting primitive values, 14670 allows setting the referrer tag, and has more powerful filtering: 14671 FollowReferences, IterateThroughHeap, and their associated 14672 callbacks, structs, enums, and constants. 14673 </change> 14674 <change date="4 June 2005" version="1.1.68"> 14675 Clarification. 14676 </change> 14677 <change date="6 June 2005" version="1.1.69"> 14678 FollowReferences, IterateThroughHeap: Put callbacks in a struct; 14679 Add missing error codes; reduce bits in the visit control flags. 14680 </change> 14681 <change date="14 June 2005" version="1.1.70"> 14682 More on new heap functionity: spec clean-up per review. 14683 </change> 14684 <change date="15 June 2005" version="1.1.71"> 14685 More on new heap functionity: Rename old heap section to Heap (1.0). 14686 </change> 14687 <change date="21 June 2005" version="1.1.72"> 14688 Fix typos. 14689 </change> 14690 <change date="27 June 2005" version="1.1.73"> 14691 Make referrer info structure a union. 14692 </change> 14693 <change date="9 September 2005" version="1.1.74"> 14694 In new heap functions: 14695 Add missing superclass reference kind. 14696 Use a single scheme for computing field indexes. 14697 Remove outdated references to struct based referrer info. 14698 </change> 14699 <change date="12 September 2005" version="1.1.75"> 14700 Don't callback during FollowReferences on frivolous java.lang.Object superclass. 14701 </change> 14702 <change date="13 September 2005" version="1.1.76"> 14703 In string primitive callback, length now Unicode length. 14704 In array and string primitive callbacks, value now "const". 14705 Note possible compiler impacts on setting JNI function table. 14706 </change> 14707 <change date="13 September 2005" version="1.1.77"> 14708 GetClassVersionNumbers() and GetConstantPool() should return 14709 error on array or primitive class. 14710 </change> 14711 <change date="14 September 2005" version="1.1.78"> 14712 Grammar fixes. 14713 </change> 14714 <change date="26 September 2005" version="1.1.79"> 14715 Add IsModifiableClass query. 14716 </change> 14717 <change date="9 February 2006" version="1.1.81"> 14718 Add referrer_class_tag parameter to jvmtiHeapReferenceCallback. 14719 </change> 14720 <change date="13 February 2006" version="1.1.82"> 14721 Doc fixes: update can_redefine_any_class to include retransform. 14722 Clarify that exception events cover all Throwables. 14723 In GetStackTrace, no test is done for start_depth too big if start_depth is zero, 14724 Clarify fields reported in Primitive Field Callback -- static vs instance. 14725 Repair confusing names of heap types, including callback names. 14726 Require consistent usage of stack depth in the face of thread launch methods. 14727 Note incompatibility of <jvmti/> memory management with other systems. 14728 </change> 14729 <change date="14 February 2006" version="1.1.85"> 14730 Fix typos and missing renames. 14731 </change> 14732 <change date="13 March 2006" version="1.1.86"> 14733 Clarify that jmethodIDs and jfieldIDs can be saved. 14734 Clarify that Iterate Over Instances Of Class includes subclasses. 14735 </change> 14736 <change date="14 March 2006" version="1.1.87"> 14737 Better phrasing. 14738 </change> 14739 <change date="16 March 2006" version="1.1.88"> 14740 Match the referrer_index for static fields in Object Reference Callback 14741 with the Reference Implementation (and all other known implementations); 14742 that is, make it match the definition for instance fields. 14743 In GetThreadListStackTraces, add JVMTI_ERROR_INVALID_THREAD to cover 14744 an invalid thread in the list; and specify that not started threads 14745 return empty stacks. 14746 </change> 14747 <change date="17 March 2006" version="1.1.89"> 14748 Typo. 14749 </change> 14750 <change date="25 March 2006" version="1.1.90"> 14751 Typo. 14752 </change> 14753 <change date="6 April 2006" version="1.1.91"> 14754 Remove restrictions on AddToBootstrapClassLoaderSearch and 14755 AddToSystemClassLoaderSearch. 14756 </change> 14757 <change date="1 May 2006" version="1.1.93"> 14758 Changed spec to return -1 for monitor stack depth for the 14759 implementation which can not determine stack depth. 14760 </change> 14761 <change date="3 May 2006" version="1.1.94"> 14762 Corrections for readability and accuracy courtesy of Alan Pratt of IBM. 14763 List the object relationships reported in FollowReferences. 14764 </change> 14765 <change date="5 May 2006" version="1.1.95"> 14766 Clarify the object relationships reported in FollowReferences. 14767 </change> 14768 <change date="28 June 2006" version="1.1.98"> 14769 Clarify DisposeEnvironment; add warning. 14770 Fix typos in SetLocalXXX "retrieve" => "set". 14771 Clarify that native method prefixes must remain set while used. 14772 Clarify that exactly one Agent_OnXXX is called per agent. 14773 Clarify that library loading is independent from start-up. 14774 Remove ambiguous reference to Agent_OnLoad in the Agent_OnUnload spec. 14775 </change> 14776 <change date="31 July 2006" version="1.1.99"> 14777 Clarify the interaction between functions and exceptions. 14778 Clarify and give examples of field indices. 14779 Remove confusing "That is" sentence from MonitorWait and MonitorWaited events. 14780 Update links to point to Java 6. 14781 </change> 14782 <change date="6 August 2006" version="1.1.102"> 14783 Add ResourceExhaustedEvent. 14784 </change> 14785 <change date="11 October 2012" version="1.2.2"> 14786 Fixed the "HTTP" and "Missing Anchor" errors reported by the LinkCheck tool. 14787 </change> 14788 <change date="19 June 2013" version="1.2.3"> 14789 Added support for statically linked agents. 14790 </change> 14791 <change date="13 October 2016" version="9.0.0"> 14792 Support for modules: 14793 - The majorversion is 9 now 14794 - The ClassFileLoadHook events are not sent during the primordial phase anymore. 14795 - Allow CompiledMethodLoad events at start phase 14796 - Add new capabilities: 14797 - can_generate_early_vmstart 14798 - can_generate_early_class_hook_events 14799 - Add new functions: 14800 - GetAllModules 14801 - AddModuleReads, AddModuleExports, AddModuleOpens, AddModuleUses, AddModuleProvides 14802 - IsModifiableModule 14803 Clarified can_redefine_any_classes, can_retransform_any_classes and IsModifiableClass API to 14804 disallow some implementation defined classes. 14805 </change> 14806 <change date="12 February 2017" version="9.0.0"> 14807 Minor update for GetCurrentThread function: 14808 - The function may return NULL in the start phase if the 14809 can_generate_early_vmstart capability is enabled. 14810 </change> 14811</changehistory> 14812 14813</specification> 14814<!-- Keep this comment at the end of the file 14815Local variables: 14816mode: sgml 14817sgml-omittag:t 14818sgml-shorttag:t 14819sgml-namecase-general:t 14820sgml-general-insert-case:lower 14821sgml-minimize-attributes:nil 14822sgml-always-quote-attributes:t 14823sgml-indent-step:2 14824sgml-indent-data:t 14825sgml-parent-document:nil 14826sgml-exposed-tags:nil 14827sgml-local-catalogs:nil 14828sgml-local-ecat-files:nil 14829End: 14830--> 14831