jvmtiImpl.hpp revision 3602:da91efe96a93
1/* 2 * Copyright (c) 1999, 2012, 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_JVMTIIMPL_HPP 26#define SHARE_VM_PRIMS_JVMTIIMPL_HPP 27 28#ifndef JVMTI_KERNEL 29 30#include "classfile/systemDictionary.hpp" 31#include "jvmtifiles/jvmti.h" 32#include "oops/objArrayOop.hpp" 33#include "prims/jvmtiEnvThreadState.hpp" 34#include "prims/jvmtiEventController.hpp" 35#include "prims/jvmtiTrace.hpp" 36#include "prims/jvmtiUtil.hpp" 37#include "runtime/stackValueCollection.hpp" 38#include "runtime/vm_operations.hpp" 39 40// 41// Forward Declarations 42// 43 44class JvmtiBreakpoint; 45class JvmtiBreakpoints; 46 47 48/////////////////////////////////////////////////////////////// 49// 50// class GrowableCache, GrowableElement 51// Used by : JvmtiBreakpointCache 52// Used by JVMTI methods: none directly. 53// 54// GrowableCache is a permanent CHeap growable array of <GrowableElement *> 55// 56// In addition, the GrowableCache maintains a NULL terminated cache array of type address 57// that's created from the element array using the function: 58// address GrowableElement::getCacheValue(). 59// 60// Whenever the GrowableArray changes size, the cache array gets recomputed into a new C_HEAP allocated 61// block of memory. Additionally, every time the cache changes its position in memory, the 62// void (*_listener_fun)(void *this_obj, address* cache) 63// gets called with the cache's new address. This gives the user of the GrowableCache a callback 64// to update its pointer to the address cache. 65// 66 67class GrowableElement : public CHeapObj<mtInternal> { 68public: 69 virtual address getCacheValue() =0; 70 virtual bool equals(GrowableElement* e) =0; 71 virtual bool lessThan(GrowableElement *e)=0; 72 virtual GrowableElement *clone() =0; 73 virtual void oops_do(OopClosure* f) =0; 74}; 75 76class GrowableCache VALUE_OBJ_CLASS_SPEC { 77 78private: 79 // Object pointer passed into cache & listener functions. 80 void *_this_obj; 81 82 // Array of elements in the collection 83 GrowableArray<GrowableElement *> *_elements; 84 85 // Parallel array of cached values 86 address *_cache; 87 88 // Listener for changes to the _cache field. 89 // Called whenever the _cache field has it's value changed 90 // (but NOT when cached elements are recomputed). 91 void (*_listener_fun)(void *, address*); 92 93 static bool equals(void *, GrowableElement *); 94 95 // recache all elements after size change, notify listener 96 void recache(); 97 98public: 99 GrowableCache(); 100 ~GrowableCache(); 101 102 void initialize(void *this_obj, void listener_fun(void *, address*) ); 103 104 // number of elements in the collection 105 int length(); 106 // get the value of the index element in the collection 107 GrowableElement* at(int index); 108 // find the index of the element, -1 if it doesn't exist 109 int find(GrowableElement* e); 110 // append a copy of the element to the end of the collection, notify listener 111 void append(GrowableElement* e); 112 // insert a copy of the element using lessthan(), notify listener 113 void insert(GrowableElement* e); 114 // remove the element at index, notify listener 115 void remove (int index); 116 // clear out all elements and release all heap space, notify listener 117 void clear(); 118 // apply f to every element and update the cache 119 void oops_do(OopClosure* f); 120 // update the cache after a full gc 121 void gc_epilogue(); 122}; 123 124 125/////////////////////////////////////////////////////////////// 126// 127// class JvmtiBreakpointCache 128// Used by : JvmtiBreakpoints 129// Used by JVMTI methods: none directly. 130// Note : typesafe wrapper for GrowableCache of JvmtiBreakpoint 131// 132 133class JvmtiBreakpointCache : public CHeapObj<mtInternal> { 134 135private: 136 GrowableCache _cache; 137 138public: 139 JvmtiBreakpointCache() {} 140 ~JvmtiBreakpointCache() {} 141 142 void initialize(void *this_obj, void listener_fun(void *, address*) ) { 143 _cache.initialize(this_obj,listener_fun); 144 } 145 146 int length() { return _cache.length(); } 147 JvmtiBreakpoint& at(int index) { return (JvmtiBreakpoint&) *(_cache.at(index)); } 148 int find(JvmtiBreakpoint& e) { return _cache.find((GrowableElement *) &e); } 149 void append(JvmtiBreakpoint& e) { _cache.append((GrowableElement *) &e); } 150 void remove (int index) { _cache.remove(index); } 151 void clear() { _cache.clear(); } 152 void oops_do(OopClosure* f) { _cache.oops_do(f); } 153 void gc_epilogue() { _cache.gc_epilogue(); } 154}; 155 156 157/////////////////////////////////////////////////////////////// 158// 159// class JvmtiBreakpoint 160// Used by : JvmtiBreakpoints 161// Used by JVMTI methods: SetBreakpoint, ClearBreakpoint, ClearAllBreakpoints 162// Note: Extends GrowableElement for use in a GrowableCache 163// 164// A JvmtiBreakpoint describes a location (class, method, bci) to break at. 165// 166 167typedef void (Method::*method_action)(int _bci); 168 169class JvmtiBreakpoint : public GrowableElement { 170private: 171 Method* _method; 172 int _bci; 173 Bytecodes::Code _orig_bytecode; 174 oop _class_loader; 175 176public: 177 JvmtiBreakpoint(); 178 JvmtiBreakpoint(Method* m_method, jlocation location); 179 bool equals(JvmtiBreakpoint& bp); 180 bool lessThan(JvmtiBreakpoint &bp); 181 void copy(JvmtiBreakpoint& bp); 182 bool is_valid(); 183 address getBcp(); 184 void each_method_version_do(method_action meth_act); 185 void set(); 186 void clear(); 187 void print(); 188 189 Method* method() { return _method; } 190 191 // GrowableElement implementation 192 address getCacheValue() { return getBcp(); } 193 bool lessThan(GrowableElement* e) { Unimplemented(); return false; } 194 bool equals(GrowableElement* e) { return equals((JvmtiBreakpoint&) *e); } 195 void oops_do(OopClosure* f) { 196 // Mark the method loader as live 197 f->do_oop(&_class_loader); 198 } 199 GrowableElement *clone() { 200 JvmtiBreakpoint *bp = new JvmtiBreakpoint(); 201 bp->copy(*this); 202 return bp; 203 } 204}; 205 206 207/////////////////////////////////////////////////////////////// 208// 209// class VM_ChangeBreakpoints 210// Used by : JvmtiBreakpoints 211// Used by JVMTI methods: none directly. 212// Note: A Helper class. 213// 214// VM_ChangeBreakpoints implements a VM_Operation for ALL modifications to the JvmtiBreakpoints class. 215// 216 217class VM_ChangeBreakpoints : public VM_Operation { 218private: 219 JvmtiBreakpoints* _breakpoints; 220 int _operation; 221 JvmtiBreakpoint* _bp; 222 223public: 224 enum { SET_BREAKPOINT=0, CLEAR_BREAKPOINT=1, CLEAR_ALL_BREAKPOINT=2 }; 225 226 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation) { 227 _breakpoints = breakpoints; 228 _bp = NULL; 229 _operation = operation; 230 assert(breakpoints != NULL, "breakpoints != NULL"); 231 assert(operation == CLEAR_ALL_BREAKPOINT, "unknown breakpoint operation"); 232 } 233 VM_ChangeBreakpoints(JvmtiBreakpoints* breakpoints, int operation, JvmtiBreakpoint *bp) { 234 _breakpoints = breakpoints; 235 _bp = bp; 236 _operation = operation; 237 assert(breakpoints != NULL, "breakpoints != NULL"); 238 assert(bp != NULL, "bp != NULL"); 239 assert(operation == SET_BREAKPOINT || operation == CLEAR_BREAKPOINT , "unknown breakpoint operation"); 240 } 241 242 VMOp_Type type() const { return VMOp_ChangeBreakpoints; } 243 void doit(); 244 void oops_do(OopClosure* f); 245}; 246 247 248/////////////////////////////////////////////////////////////// 249// 250// class JvmtiBreakpoints 251// Used by : JvmtiCurrentBreakpoints 252// Used by JVMTI methods: none directly 253// Note: A Helper class 254// 255// JvmtiBreakpoints is a GrowableCache of JvmtiBreakpoint. 256// All changes to the GrowableCache occur at a safepoint using VM_ChangeBreakpoints. 257// 258// Because _bps is only modified at safepoints, its possible to always use the 259// cached byte code pointers from _bps without doing any synchronization (see JvmtiCurrentBreakpoints). 260// 261// It would be possible to make JvmtiBreakpoints a static class, but I've made it 262// CHeap allocated to emphasize its similarity to JvmtiFramePops. 263// 264 265class JvmtiBreakpoints : public CHeapObj<mtInternal> { 266private: 267 268 JvmtiBreakpointCache _bps; 269 270 // These should only be used by VM_ChangeBreakpoints 271 // to insure they only occur at safepoints. 272 // Todo: add checks for safepoint 273 friend class VM_ChangeBreakpoints; 274 void set_at_safepoint(JvmtiBreakpoint& bp); 275 void clear_at_safepoint(JvmtiBreakpoint& bp); 276 void clearall_at_safepoint(); 277 278 static void do_element(GrowableElement *e); 279 280public: 281 JvmtiBreakpoints(void listener_fun(void *, address *)); 282 ~JvmtiBreakpoints(); 283 284 int length(); 285 void oops_do(OopClosure* f); 286 void print(); 287 288 int set(JvmtiBreakpoint& bp); 289 int clear(JvmtiBreakpoint& bp); 290 void clearall_in_class_at_safepoint(Klass* klass); 291 void clearall(); 292 void gc_epilogue(); 293}; 294 295 296/////////////////////////////////////////////////////////////// 297// 298// class JvmtiCurrentBreakpoints 299// 300// A static wrapper class for the JvmtiBreakpoints that provides: 301// 1. a fast inlined function to check if a byte code pointer is a breakpoint (is_breakpoint). 302// 2. a function for lazily creating the JvmtiBreakpoints class (this is not strictly necessary, 303// but I'm copying the code from JvmtiThreadState which needs to lazily initialize 304// JvmtiFramePops). 305// 3. An oops_do entry point for GC'ing the breakpoint array. 306// 307 308class JvmtiCurrentBreakpoints : public AllStatic { 309 310private: 311 312 // Current breakpoints, lazily initialized by get_jvmti_breakpoints(); 313 static JvmtiBreakpoints *_jvmti_breakpoints; 314 315 // NULL terminated cache of byte-code pointers corresponding to current breakpoints. 316 // Updated only at safepoints (with listener_fun) when the cache is moved. 317 // It exists only to make is_breakpoint fast. 318 static address *_breakpoint_list; 319 static inline void set_breakpoint_list(address *breakpoint_list) { _breakpoint_list = breakpoint_list; } 320 static inline address *get_breakpoint_list() { return _breakpoint_list; } 321 322 // Listener for the GrowableCache in _jvmti_breakpoints, updates _breakpoint_list. 323 static void listener_fun(void *this_obj, address *cache); 324 325public: 326 static void initialize(); 327 static void destroy(); 328 329 // lazily create _jvmti_breakpoints and _breakpoint_list 330 static JvmtiBreakpoints& get_jvmti_breakpoints(); 331 332 // quickly test whether the bcp matches a cached breakpoint in the list 333 static inline bool is_breakpoint(address bcp); 334 335 static void oops_do(OopClosure* f); 336 static void gc_epilogue(); 337}; 338 339// quickly test whether the bcp matches a cached breakpoint in the list 340bool JvmtiCurrentBreakpoints::is_breakpoint(address bcp) { 341 address *bps = get_breakpoint_list(); 342 if (bps == NULL) return false; 343 for ( ; (*bps) != NULL; bps++) { 344 if ((*bps) == bcp) return true; 345 } 346 return false; 347} 348 349/////////////////////////////////////////////////////////////// 350// The get/set local operations must only be done by the VM thread 351// because the interpreter version needs to access oop maps, which can 352// only safely be done by the VM thread 353// 354// I'm told that in 1.5 oop maps are now protected by a lock and 355// we could get rid of the VM op 356// However if the VM op is removed then the target thread must 357// be suspended AND a lock will be needed to prevent concurrent 358// setting of locals to the same java thread. This lock is needed 359// to prevent compiledVFrames from trying to add deferred updates 360// to the thread simultaneously. 361// 362class VM_GetOrSetLocal : public VM_Operation { 363 protected: 364 JavaThread* _thread; 365 JavaThread* _calling_thread; 366 jint _depth; 367 jint _index; 368 BasicType _type; 369 jvalue _value; 370 javaVFrame* _jvf; 371 bool _set; 372 373 // It is possible to get the receiver out of a non-static native wrapper 374 // frame. Use VM_GetReceiver to do this. 375 virtual bool getting_receiver() const { return false; } 376 377 jvmtiError _result; 378 379 vframe* get_vframe(); 380 javaVFrame* get_java_vframe(); 381 bool check_slot_type(javaVFrame* vf); 382 383public: 384 // Constructor for non-object getter 385 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type); 386 387 // Constructor for object or non-object setter 388 VM_GetOrSetLocal(JavaThread* thread, jint depth, jint index, BasicType type, jvalue value); 389 390 // Constructor for object getter 391 VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, 392 int index); 393 394 VMOp_Type type() const { return VMOp_GetOrSetLocal; } 395 jvalue value() { return _value; } 396 jvmtiError result() { return _result; } 397 398 bool doit_prologue(); 399 void doit(); 400 bool allow_nested_vm_operations() const; 401 const char* name() const { return "get/set locals"; } 402 403 // Check that the klass is assignable to a type with the given signature. 404 static bool is_assignable(const char* ty_sign, Klass* klass, Thread* thread); 405}; 406 407class VM_GetReceiver : public VM_GetOrSetLocal { 408 protected: 409 virtual bool getting_receiver() const { return true; } 410 411 public: 412 VM_GetReceiver(JavaThread* thread, JavaThread* calling_thread, jint depth); 413 const char* name() const { return "get receiver"; } 414}; 415 416 417/////////////////////////////////////////////////////////////// 418// 419// class JvmtiSuspendControl 420// 421// Convenience routines for suspending and resuming threads. 422// 423// All attempts by JVMTI to suspend and resume threads must go through the 424// JvmtiSuspendControl interface. 425// 426// methods return true if successful 427// 428class JvmtiSuspendControl : public AllStatic { 429public: 430 // suspend the thread, taking it to a safepoint 431 static bool suspend(JavaThread *java_thread); 432 // resume the thread 433 static bool resume(JavaThread *java_thread); 434 435 static void print(); 436}; 437 438#endif // !JVMTI_KERNEL 439 440/** 441 * When a thread (such as the compiler thread or VM thread) cannot post a 442 * JVMTI event itself because the event needs to be posted from a Java 443 * thread, then it can defer the event to the Service thread for posting. 444 * The information needed to post the event is encapsulated into this class 445 * and then enqueued onto the JvmtiDeferredEventQueue, where the Service 446 * thread will pick it up and post it. 447 * 448 * This is currently only used for posting compiled-method-load and unload 449 * events, which we don't want posted from the compiler thread. 450 */ 451class JvmtiDeferredEvent VALUE_OBJ_CLASS_SPEC { 452 friend class JvmtiDeferredEventQueue; 453 private: 454 typedef enum { 455 TYPE_NONE, 456 TYPE_COMPILED_METHOD_LOAD, 457 TYPE_COMPILED_METHOD_UNLOAD, 458 TYPE_DYNAMIC_CODE_GENERATED 459 } Type; 460 461 Type _type; 462 union { 463 nmethod* compiled_method_load; 464 struct { 465 nmethod* nm; 466 jmethodID method_id; 467 const void* code_begin; 468 } compiled_method_unload; 469 struct { 470 const char* name; 471 const void* code_begin; 472 const void* code_end; 473 } dynamic_code_generated; 474 } _event_data; 475 476 JvmtiDeferredEvent(Type t) : _type(t) {} 477 478 public: 479 480 JvmtiDeferredEvent() : _type(TYPE_NONE) {} 481 482 // Factory methods 483 static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm) 484 KERNEL_RETURN_(JvmtiDeferredEvent()); 485 static JvmtiDeferredEvent compiled_method_unload_event(nmethod* nm, 486 jmethodID id, const void* code) KERNEL_RETURN_(JvmtiDeferredEvent()); 487 static JvmtiDeferredEvent dynamic_code_generated_event( 488 const char* name, const void* begin, const void* end) 489 KERNEL_RETURN_(JvmtiDeferredEvent()); 490 491 // Actually posts the event. 492 void post() KERNEL_RETURN; 493}; 494 495/** 496 * Events enqueued on this queue wake up the Service thread which dequeues 497 * and posts the events. The Service_lock is required to be held 498 * when operating on the queue (except for the "pending" events). 499 */ 500class JvmtiDeferredEventQueue : AllStatic { 501 friend class JvmtiDeferredEvent; 502 private: 503 class QueueNode : public CHeapObj<mtInternal> { 504 private: 505 JvmtiDeferredEvent _event; 506 QueueNode* _next; 507 508 public: 509 QueueNode(const JvmtiDeferredEvent& event) 510 : _event(event), _next(NULL) {} 511 512 const JvmtiDeferredEvent& event() const { return _event; } 513 QueueNode* next() const { return _next; } 514 515 void set_next(QueueNode* next) { _next = next; } 516 }; 517 518 static QueueNode* _queue_head; // Hold Service_lock to access 519 static QueueNode* _queue_tail; // Hold Service_lock to access 520 static volatile QueueNode* _pending_list; // Uses CAS for read/update 521 522 // Transfers events from the _pending_list to the _queue. 523 static void process_pending_events() KERNEL_RETURN; 524 525 public: 526 // Must be holding Service_lock when calling these 527 static bool has_events() KERNEL_RETURN_(false); 528 static void enqueue(const JvmtiDeferredEvent& event) KERNEL_RETURN; 529 static JvmtiDeferredEvent dequeue() KERNEL_RETURN_(JvmtiDeferredEvent()); 530 531 // Used to enqueue events without using a lock, for times (such as during 532 // safepoint) when we can't or don't want to lock the Service_lock. 533 // 534 // Events will be held off to the side until there's a call to 535 // dequeue(), enqueue(), or process_pending_events() (all of which require 536 // the holding of the Service_lock), and will be enqueued at that time. 537 static void add_pending_event(const JvmtiDeferredEvent&) KERNEL_RETURN; 538}; 539 540// Utility macro that checks for NULL pointers: 541#define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); } 542 543#endif // SHARE_VM_PRIMS_JVMTIIMPL_HPP 544