1/* 2 * Copyright (c) 1998, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25#ifndef SHARE_VM_PRIMS_JVMTIEXPORT_HPP 26#define SHARE_VM_PRIMS_JVMTIEXPORT_HPP 27 28#include "jvmtifiles/jvmti.h" 29#include "memory/allocation.hpp" 30#include "memory/iterator.hpp" 31#include "oops/oop.hpp" 32#include "oops/oopsHierarchy.hpp" 33#include "runtime/frame.hpp" 34#include "runtime/handles.hpp" 35#include "utilities/globalDefinitions.hpp" 36#include "utilities/growableArray.hpp" 37#include "utilities/macros.hpp" 38 39// Must be included after jvmti.h. 40#include "code/jvmticmlr.h" 41 42// Forward declarations 43 44class JvmtiEventControllerPrivate; 45class JvmtiManageCapabilities; 46class JvmtiEnv; 47class JvmtiThreadState; 48 49#define JVMTI_SUPPORT_FLAG(key) \ 50 private: \ 51 static bool _##key; \ 52 public: \ 53 inline static void set_##key(bool on) { \ 54 JVMTI_ONLY(_##key = (on != 0)); \ 55 NOT_JVMTI(report_unsupported(on)); \ 56 } \ 57 inline static bool key() { \ 58 JVMTI_ONLY(return _##key); \ 59 NOT_JVMTI(return false); \ 60 } 61 62 63// This class contains the JVMTI interface for the rest of hotspot. 64// 65class JvmtiExport : public AllStatic { 66 friend class VMStructs; 67 friend class CompileReplay; 68 69 private: 70 71#if INCLUDE_JVMTI 72 static int _field_access_count; 73 static int _field_modification_count; 74 75 static bool _can_access_local_variables; 76 static bool _can_hotswap_or_post_breakpoint; 77 static bool _can_modify_any_class; 78 static bool _can_walk_any_space; 79#endif // INCLUDE_JVMTI 80 81 JVMTI_SUPPORT_FLAG(can_get_source_debug_extension) 82 JVMTI_SUPPORT_FLAG(can_maintain_original_method_order) 83 JVMTI_SUPPORT_FLAG(can_post_interpreter_events) 84 JVMTI_SUPPORT_FLAG(can_post_on_exceptions) 85 JVMTI_SUPPORT_FLAG(can_post_breakpoint) 86 JVMTI_SUPPORT_FLAG(can_post_field_access) 87 JVMTI_SUPPORT_FLAG(can_post_field_modification) 88 JVMTI_SUPPORT_FLAG(can_post_method_entry) 89 JVMTI_SUPPORT_FLAG(can_post_method_exit) 90 JVMTI_SUPPORT_FLAG(can_pop_frame) 91 JVMTI_SUPPORT_FLAG(can_force_early_return) 92 93 JVMTI_SUPPORT_FLAG(early_vmstart_recorded) 94 95 friend class JvmtiEventControllerPrivate; // should only modify these flags 96 JVMTI_SUPPORT_FLAG(should_post_single_step) 97 JVMTI_SUPPORT_FLAG(should_post_field_access) 98 JVMTI_SUPPORT_FLAG(should_post_field_modification) 99 JVMTI_SUPPORT_FLAG(should_post_class_load) 100 JVMTI_SUPPORT_FLAG(should_post_class_prepare) 101 JVMTI_SUPPORT_FLAG(should_post_class_unload) 102 JVMTI_SUPPORT_FLAG(should_post_native_method_bind) 103 JVMTI_SUPPORT_FLAG(should_post_compiled_method_load) 104 JVMTI_SUPPORT_FLAG(should_post_compiled_method_unload) 105 JVMTI_SUPPORT_FLAG(should_post_dynamic_code_generated) 106 JVMTI_SUPPORT_FLAG(should_post_monitor_contended_enter) 107 JVMTI_SUPPORT_FLAG(should_post_monitor_contended_entered) 108 JVMTI_SUPPORT_FLAG(should_post_monitor_wait) 109 JVMTI_SUPPORT_FLAG(should_post_monitor_waited) 110 JVMTI_SUPPORT_FLAG(should_post_data_dump) 111 JVMTI_SUPPORT_FLAG(should_post_garbage_collection_start) 112 JVMTI_SUPPORT_FLAG(should_post_garbage_collection_finish) 113 JVMTI_SUPPORT_FLAG(should_post_on_exceptions) 114 115 // ------ the below maybe don't have to be (but are for now) 116 // fixed conditions here ------------ 117 // any events can be enabled 118 JVMTI_SUPPORT_FLAG(should_post_thread_life) 119 JVMTI_SUPPORT_FLAG(should_post_object_free) 120 JVMTI_SUPPORT_FLAG(should_post_resource_exhausted) 121 122 // we are holding objects on the heap - need to talk to GC - e.g. 123 // breakpoint info 124 JVMTI_SUPPORT_FLAG(should_clean_up_heap_objects) 125 JVMTI_SUPPORT_FLAG(should_post_vm_object_alloc) 126 127 // If flag cannot be implemented, give an error if on=true 128 static void report_unsupported(bool on); 129 130 // these should only be called by the friend class 131 friend class JvmtiManageCapabilities; 132 inline static void set_can_modify_any_class(bool on) { 133 JVMTI_ONLY(_can_modify_any_class = (on != 0);) 134 } 135 inline static void set_can_access_local_variables(bool on) { 136 JVMTI_ONLY(_can_access_local_variables = (on != 0);) 137 } 138 inline static void set_can_hotswap_or_post_breakpoint(bool on) { 139 JVMTI_ONLY(_can_hotswap_or_post_breakpoint = (on != 0);) 140 } 141 inline static void set_can_walk_any_space(bool on) { 142 JVMTI_ONLY(_can_walk_any_space = (on != 0);) 143 } 144 145 enum { 146 JVMTI_VERSION_MASK = 0x70000000, 147 JVMTI_VERSION_VALUE = 0x30000000, 148 JVMDI_VERSION_VALUE = 0x20000000 149 }; 150 151 static void post_field_modification(JavaThread *thread, Method* method, address location, 152 Klass* field_klass, Handle object, jfieldID field, 153 char sig_type, jvalue *value); 154 155 156 // posts a DynamicCodeGenerated event (internal/private implementation). 157 // The public post_dynamic_code_generated* functions make use of the 158 // internal implementation. Also called from JvmtiDeferredEvent::post() 159 static void post_dynamic_code_generated_internal(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN; 160 161 private: 162 163 // GenerateEvents support to allow posting of CompiledMethodLoad and 164 // DynamicCodeGenerated events for a given environment. 165 friend class JvmtiCodeBlobEvents; 166 167 static void post_compiled_method_load(JvmtiEnv* env, const jmethodID method, const jint length, 168 const void *code_begin, const jint map_length, 169 const jvmtiAddrLocationMap* map) NOT_JVMTI_RETURN; 170 static void post_dynamic_code_generated(JvmtiEnv* env, const char *name, const void *code_begin, 171 const void *code_end) NOT_JVMTI_RETURN; 172 173 // The RedefineClasses() API breaks some invariants in the "regular" 174 // system. For example, there are sanity checks when GC'ing nmethods 175 // that require the containing class to be unloading. However, when a 176 // method is redefined, the old method and nmethod can become GC'able 177 // without the containing class unloading. The state of becoming 178 // GC'able can be asynchronous to the RedefineClasses() call since 179 // the old method may still be running and cannot be GC'ed until 180 // after all old invocations have finished. Additionally, a method 181 // that has not been redefined may have an nmethod that depends on 182 // the redefined method. The dependent nmethod will get deopted in 183 // this case and may also be GC'able without the containing class 184 // being unloaded. 185 // 186 // This flag indicates whether RedefineClasses() has ever redefined 187 // one or more classes during the lifetime of the VM. The flag should 188 // only be set by the friend class and can be queried by other sub 189 // systems as needed to relax invariant checks. 190 static bool _has_redefined_a_class; 191 friend class VM_RedefineClasses; 192 inline static void set_has_redefined_a_class() { 193 JVMTI_ONLY(_has_redefined_a_class = true;) 194 } 195 // Flag to indicate if the compiler has recorded all dependencies. When the 196 // can_redefine_classes capability is enabled in the OnLoad phase then the compiler 197 // records all dependencies from startup. However if the capability is first 198 // enabled some time later then the dependencies recorded by the compiler 199 // are incomplete. This flag is used by RedefineClasses to know if the 200 // dependency information is complete or not. 201 static bool _all_dependencies_are_recorded; 202 203 public: 204 inline static bool has_redefined_a_class() { 205 JVMTI_ONLY(return _has_redefined_a_class); 206 NOT_JVMTI(return false); 207 } 208 209 inline static bool all_dependencies_are_recorded() { 210 return _all_dependencies_are_recorded; 211 } 212 213 inline static void set_all_dependencies_are_recorded(bool on) { 214 _all_dependencies_are_recorded = (on != 0); 215 } 216 217 // Add read edges to the unnamed modules of the bootstrap and app class loaders 218 static void add_default_read_edges(Handle h_module, TRAPS) NOT_JVMTI_RETURN; 219 220 // Add a read edge to the module 221 static jvmtiError add_module_reads(Handle module, Handle to_module, TRAPS); 222 223 // Updates a module to export a package 224 static jvmtiError add_module_exports(Handle module, Handle pkg_name, Handle to_module, TRAPS); 225 226 // Updates a module to open a package 227 static jvmtiError add_module_opens(Handle module, Handle pkg_name, Handle to_module, TRAPS); 228 229 // Add a used service to the module 230 static jvmtiError add_module_uses(Handle module, Handle service, TRAPS); 231 232 // Add a service provider to the module 233 static jvmtiError add_module_provides(Handle module, Handle service, Handle impl_class, TRAPS); 234 235 // let JVMTI know that the JVM_OnLoad code is running 236 static void enter_onload_phase() NOT_JVMTI_RETURN; 237 238 // let JVMTI know that the VM isn't up yet (and JVM_OnLoad code isn't running) 239 static void enter_primordial_phase() NOT_JVMTI_RETURN; 240 241 // let JVMTI know that the VM isn't up yet but JNI is live 242 static void enter_early_start_phase() NOT_JVMTI_RETURN; 243 static void enter_start_phase() NOT_JVMTI_RETURN; 244 245 // let JVMTI know that the VM is fully up and running now 246 static void enter_live_phase() NOT_JVMTI_RETURN; 247 248 // ------ can_* conditions (below) are set at OnLoad and never changed ------------ 249 inline static bool can_modify_any_class() { 250 JVMTI_ONLY(return _can_modify_any_class); 251 NOT_JVMTI(return false); 252 } 253 inline static bool can_access_local_variables() { 254 JVMTI_ONLY(return _can_access_local_variables); 255 NOT_JVMTI(return false); 256 } 257 inline static bool can_hotswap_or_post_breakpoint() { 258 JVMTI_ONLY(return _can_hotswap_or_post_breakpoint); 259 NOT_JVMTI(return false); 260 } 261 inline static bool can_walk_any_space() { 262 JVMTI_ONLY(return _can_walk_any_space); 263 NOT_JVMTI(return false); 264 } 265 266 // field access management 267 static address get_field_access_count_addr() NOT_JVMTI_RETURN_(0); 268 269 // field modification management 270 static address get_field_modification_count_addr() NOT_JVMTI_RETURN_(0); 271 272 // ----------------- 273 274 static bool is_jvmti_version(jint version) { 275 JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMTI_VERSION_VALUE); 276 NOT_JVMTI(return false); 277 } 278 static bool is_jvmdi_version(jint version) { 279 JVMTI_ONLY(return (version & JVMTI_VERSION_MASK) == JVMDI_VERSION_VALUE); 280 NOT_JVMTI(return false); 281 } 282 static jint get_jvmti_interface(JavaVM *jvm, void **penv, jint version) NOT_JVMTI_RETURN_(0); 283 static void decode_version_values(jint version, int * major, int * minor, 284 int * micro) NOT_JVMTI_RETURN; 285 286 // single stepping management methods 287 static void at_single_stepping_point(JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN; 288 static void expose_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN; 289 static bool hide_single_stepping(JavaThread *thread) NOT_JVMTI_RETURN_(false); 290 291 // Methods that notify the debugger that something interesting has happened in the VM. 292 static void post_early_vm_start () NOT_JVMTI_RETURN; 293 static void post_vm_start () NOT_JVMTI_RETURN; 294 static void post_vm_initialized () NOT_JVMTI_RETURN; 295 static void post_vm_death () NOT_JVMTI_RETURN; 296 297 static void post_single_step (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN; 298 static void post_raw_breakpoint (JavaThread *thread, Method* method, address location) NOT_JVMTI_RETURN; 299 300 static void post_exception_throw (JavaThread *thread, Method* method, address location, oop exception) NOT_JVMTI_RETURN; 301 static void notice_unwind_due_to_exception (JavaThread *thread, Method* method, address location, oop exception, bool in_handler_frame) NOT_JVMTI_RETURN; 302 303 static oop jni_GetField_probe (JavaThread *thread, jobject jobj, 304 oop obj, Klass* klass, jfieldID fieldID, bool is_static) 305 NOT_JVMTI_RETURN_(NULL); 306 static oop jni_GetField_probe_nh (JavaThread *thread, jobject jobj, 307 oop obj, Klass* klass, jfieldID fieldID, bool is_static) 308 NOT_JVMTI_RETURN_(NULL); 309 static void post_field_access_by_jni (JavaThread *thread, oop obj, 310 Klass* klass, jfieldID fieldID, bool is_static) NOT_JVMTI_RETURN; 311 static void post_field_access (JavaThread *thread, Method* method, 312 address location, Klass* field_klass, Handle object, jfieldID field) NOT_JVMTI_RETURN; 313 static oop jni_SetField_probe (JavaThread *thread, jobject jobj, 314 oop obj, Klass* klass, jfieldID fieldID, bool is_static, char sig_type, 315 jvalue *value) NOT_JVMTI_RETURN_(NULL); 316 static oop jni_SetField_probe_nh (JavaThread *thread, jobject jobj, 317 oop obj, Klass* klass, jfieldID fieldID, bool is_static, char sig_type, 318 jvalue *value) NOT_JVMTI_RETURN_(NULL); 319 static void post_field_modification_by_jni(JavaThread *thread, oop obj, 320 Klass* klass, jfieldID fieldID, bool is_static, char sig_type, 321 jvalue *value); 322 static void post_raw_field_modification(JavaThread *thread, Method* method, 323 address location, Klass* field_klass, Handle object, jfieldID field, 324 char sig_type, jvalue *value) NOT_JVMTI_RETURN; 325 326 static void post_method_entry (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN; 327 static void post_method_exit (JavaThread *thread, Method* method, frame current_frame) NOT_JVMTI_RETURN; 328 329 static void post_class_load (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN; 330 static void post_class_unload (Klass* klass) NOT_JVMTI_RETURN; 331 static void post_class_prepare (JavaThread *thread, Klass* klass) NOT_JVMTI_RETURN; 332 333 static void post_thread_start (JavaThread *thread) NOT_JVMTI_RETURN; 334 static void post_thread_end (JavaThread *thread) NOT_JVMTI_RETURN; 335 336 // Support for java.lang.instrument agent loading. 337 static bool _should_post_class_file_load_hook; 338 inline static void set_should_post_class_file_load_hook(bool on) { _should_post_class_file_load_hook = on; } 339 inline static bool should_post_class_file_load_hook() { 340 JVMTI_ONLY(return _should_post_class_file_load_hook); 341 NOT_JVMTI(return false;) 342 } 343 // Return true if the class was modified by the hook. 344 static bool post_class_file_load_hook(Symbol* h_name, Handle class_loader, 345 Handle h_protection_domain, 346 unsigned char **data_ptr, unsigned char **end_ptr, 347 JvmtiCachedClassFileData **cache_ptr) NOT_JVMTI_RETURN_(false); 348 static void post_native_method_bind(Method* method, address* function_ptr) NOT_JVMTI_RETURN; 349 static void post_compiled_method_load(nmethod *nm) NOT_JVMTI_RETURN; 350 static void post_dynamic_code_generated(const char *name, const void *code_begin, const void *code_end) NOT_JVMTI_RETURN; 351 352 // used to post a CompiledMethodUnload event 353 static void post_compiled_method_unload(jmethodID mid, const void *code_begin) NOT_JVMTI_RETURN; 354 355 // similiar to post_dynamic_code_generated except that it can be used to 356 // post a DynamicCodeGenerated event while holding locks in the VM. Any event 357 // posted using this function is recorded by the enclosing event collector 358 // -- JvmtiDynamicCodeEventCollector. 359 static void post_dynamic_code_generated_while_holding_locks(const char* name, address code_begin, address code_end) NOT_JVMTI_RETURN; 360 361 static void post_garbage_collection_finish() NOT_JVMTI_RETURN; 362 static void post_garbage_collection_start() NOT_JVMTI_RETURN; 363 static void post_data_dump() NOT_JVMTI_RETURN; 364 static void post_monitor_contended_enter(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN; 365 static void post_monitor_contended_entered(JavaThread *thread, ObjectMonitor *obj_mntr) NOT_JVMTI_RETURN; 366 static void post_monitor_wait(JavaThread *thread, oop obj, jlong timeout) NOT_JVMTI_RETURN; 367 static void post_monitor_waited(JavaThread *thread, ObjectMonitor *obj_mntr, jboolean timed_out) NOT_JVMTI_RETURN; 368 static void post_object_free(JvmtiEnv* env, jlong tag) NOT_JVMTI_RETURN; 369 static void post_resource_exhausted(jint resource_exhausted_flags, const char* detail) NOT_JVMTI_RETURN; 370 static void record_vm_internal_object_allocation(oop object) NOT_JVMTI_RETURN; 371 // Post objects collected by vm_object_alloc_event_collector. 372 static void post_vm_object_alloc(JavaThread *thread, oop object) NOT_JVMTI_RETURN; 373 // Collects vm internal objects for later event posting. 374 inline static void vm_object_alloc_event_collector(oop object) { 375 if (should_post_vm_object_alloc()) { 376 record_vm_internal_object_allocation(object); 377 } 378 } 379 inline static void post_array_size_exhausted() { 380 if (should_post_resource_exhausted()) { 381 post_resource_exhausted(JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR, 382 "Requested array size exceeds VM limit"); 383 } 384 } 385 386 static void cleanup_thread (JavaThread* thread) NOT_JVMTI_RETURN; 387 static void clear_detected_exception (JavaThread* thread) NOT_JVMTI_RETURN; 388 389 static void oops_do(OopClosure* f) NOT_JVMTI_RETURN; 390 static void weak_oops_do(BoolObjectClosure* b, OopClosure* f) NOT_JVMTI_RETURN; 391 static void gc_epilogue() NOT_JVMTI_RETURN; 392 393 static void transition_pending_onload_raw_monitors() NOT_JVMTI_RETURN; 394 395#if INCLUDE_SERVICES 396 // attach support 397 static jint load_agent_library(const char *agent, const char *absParam, const char *options, outputStream* out) NOT_JVMTI_RETURN_(JNI_ERR); 398#endif 399 400 // SetNativeMethodPrefix support 401 static char** get_all_native_method_prefixes(int* count_ptr) NOT_JVMTI_RETURN_(NULL); 402}; 403 404// Support class used by JvmtiDynamicCodeEventCollector and others. It 405// describes a single code blob by name and address range. 406class JvmtiCodeBlobDesc : public CHeapObj<mtInternal> { 407 private: 408 char _name[64]; 409 address _code_begin; 410 address _code_end; 411 412 public: 413 JvmtiCodeBlobDesc(const char *name, address code_begin, address code_end) { 414 assert(name != NULL, "all code blobs must be named"); 415 strncpy(_name, name, sizeof(_name)); 416 _name[sizeof(_name)-1] = '\0'; 417 _code_begin = code_begin; 418 _code_end = code_end; 419 } 420 char* name() { return _name; } 421 address code_begin() { return _code_begin; } 422 address code_end() { return _code_end; } 423}; 424 425// JvmtiEventCollector is a helper class to setup thread for 426// event collection. 427class JvmtiEventCollector : public StackObj { 428 private: 429 JvmtiEventCollector* _prev; // Save previous one to support nested event collector. 430 431 public: 432 void setup_jvmti_thread_state(); // Set this collector in current thread. 433 void unset_jvmti_thread_state(); // Reset previous collector in current thread. 434 virtual bool is_dynamic_code_event() { return false; } 435 virtual bool is_vm_object_alloc_event(){ return false; } 436 JvmtiEventCollector *get_prev() { return _prev; } 437}; 438 439// A JvmtiDynamicCodeEventCollector is a helper class for the JvmtiExport 440// interface. It collects "dynamic code generated" events that are posted 441// while holding locks. When the event collector goes out of scope the 442// events will be posted. 443// 444// Usage :- 445// 446// { 447// JvmtiDynamicCodeEventCollector event_collector; 448// : 449// { MutexLocker ml(...) 450// : 451// JvmtiExport::post_dynamic_code_generated_while_holding_locks(...) 452// } 453// // event collector goes out of scope => post events to profiler. 454// } 455 456class JvmtiDynamicCodeEventCollector : public JvmtiEventCollector { 457 private: 458 GrowableArray<JvmtiCodeBlobDesc*>* _code_blobs; // collected code blob events 459 460 friend class JvmtiExport; 461 void register_stub(const char* name, address start, address end); 462 463 public: 464 JvmtiDynamicCodeEventCollector() NOT_JVMTI_RETURN; 465 ~JvmtiDynamicCodeEventCollector() NOT_JVMTI_RETURN; 466 bool is_dynamic_code_event() { return true; } 467 468}; 469 470// Used to record vm internally allocated object oops and post 471// vm object alloc event for objects visible to java world. 472// Constructor enables JvmtiThreadState flag and all vm allocated 473// objects are recorded in a growable array. When destructor is 474// called the vm object alloc event is posted for each objects 475// visible to java world. 476// See jvm.cpp file for its usage. 477// 478class JvmtiVMObjectAllocEventCollector : public JvmtiEventCollector { 479 private: 480 GrowableArray<oop>* _allocated; // field to record vm internally allocated object oop. 481 bool _enable; // This flag is enabled in constructor and disabled 482 // in destructor before posting event. To avoid 483 // collection of objects allocated while running java code inside 484 // agent post_vm_object_alloc() event handler. 485 486 //GC support 487 void oops_do(OopClosure* f); 488 489 friend class JvmtiExport; 490 // Record vm allocated object oop. 491 inline void record_allocation(oop obj); 492 493 //GC support 494 static void oops_do_for_all_threads(OopClosure* f); 495 496 public: 497 JvmtiVMObjectAllocEventCollector() NOT_JVMTI_RETURN; 498 ~JvmtiVMObjectAllocEventCollector() NOT_JVMTI_RETURN; 499 bool is_vm_object_alloc_event() { return true; } 500 501 bool is_enabled() { return _enable; } 502 void set_enabled(bool on) { _enable = on; } 503}; 504 505 506 507// Marker class to disable the posting of VMObjectAlloc events 508// within its scope. 509// 510// Usage :- 511// 512// { 513// NoJvmtiVMObjectAllocMark njm; 514// : 515// // VMObjAlloc event will not be posted 516// JvmtiExport::vm_object_alloc_event_collector(obj); 517// : 518// } 519 520class NoJvmtiVMObjectAllocMark : public StackObj { 521 private: 522 // enclosing collector if enabled, NULL otherwise 523 JvmtiVMObjectAllocEventCollector *_collector; 524 525 bool was_enabled() { return _collector != NULL; } 526 527 public: 528 NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN; 529 ~NoJvmtiVMObjectAllocMark() NOT_JVMTI_RETURN; 530}; 531 532 533// Base class for reporting GC events to JVMTI. 534class JvmtiGCMarker : public StackObj { 535 public: 536 JvmtiGCMarker() NOT_JVMTI_RETURN; 537 ~JvmtiGCMarker() NOT_JVMTI_RETURN; 538}; 539 540// JvmtiHideSingleStepping is a helper class for hiding 541// internal single step events. 542class JvmtiHideSingleStepping : public StackObj { 543 private: 544 bool _single_step_hidden; 545 JavaThread * _thread; 546 547 public: 548 JvmtiHideSingleStepping(JavaThread * thread) { 549 assert(thread != NULL, "sanity check"); 550 551 _single_step_hidden = false; 552 _thread = thread; 553 if (JvmtiExport::should_post_single_step()) { 554 _single_step_hidden = JvmtiExport::hide_single_stepping(_thread); 555 } 556 } 557 558 ~JvmtiHideSingleStepping() { 559 if (_single_step_hidden) { 560 JvmtiExport::expose_single_stepping(_thread); 561 } 562 } 563}; 564 565#endif // SHARE_VM_PRIMS_JVMTIEXPORT_HPP 566