threadService.hpp revision 0:a61af66fc99e
1/* 2 * Copyright 2003-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25class OopClosure; 26class ThreadDumpResult; 27class ThreadStackTrace; 28class ThreadSnapshot; 29class StackFrameInfo; 30class ThreadConcurrentLocks; 31class DeadlockCycle; 32 33// VM monitoring and management support for the thread and 34// synchronization subsystem 35// 36// Thread contention monitoring is disabled by default. 37// When enabled, the VM will begin measuring the accumulated 38// elapsed time a thread blocked on synchronization. 39// 40class ThreadService : public AllStatic { 41private: 42 // These counters could be moved to Threads class 43 static PerfCounter* _total_threads_count; 44 static PerfVariable* _live_threads_count; 45 static PerfVariable* _peak_threads_count; 46 static PerfVariable* _daemon_threads_count; 47 48 // These 2 counters are atomically incremented once the thread is exiting. 49 // They will be atomically decremented when ThreadService::remove_thread is called. 50 static volatile int _exiting_threads_count; 51 static volatile int _exiting_daemon_threads_count; 52 53 static bool _thread_monitoring_contention_enabled; 54 static bool _thread_cpu_time_enabled; 55 56 // Need to keep the list of thread dump result that 57 // keep references to methodOop since thread dump can be 58 // requested by multiple threads concurrently. 59 static ThreadDumpResult* _threaddump_list; 60 61public: 62 static void init(); 63 static void add_thread(JavaThread* thread, bool daemon); 64 static void remove_thread(JavaThread* thread, bool daemon); 65 static void current_thread_exiting(JavaThread* jt); 66 67 static bool set_thread_monitoring_contention(bool flag); 68 static bool is_thread_monitoring_contention() { return _thread_monitoring_contention_enabled; } 69 70 static bool set_thread_cpu_time_enabled(bool flag); 71 static bool is_thread_cpu_time_enabled() { return _thread_cpu_time_enabled; } 72 73 static jlong get_total_thread_count() { return _total_threads_count->get_value(); } 74 static jlong get_peak_thread_count() { return _peak_threads_count->get_value(); } 75 static jlong get_live_thread_count() { return _live_threads_count->get_value() - _exiting_threads_count; } 76 static jlong get_daemon_thread_count() { return _daemon_threads_count->get_value() - _exiting_daemon_threads_count; } 77 78 static int exiting_threads_count() { return _exiting_threads_count; } 79 static int exiting_daemon_threads_count() { return _exiting_daemon_threads_count; } 80 81 // Support for thread dump 82 static void add_thread_dump(ThreadDumpResult* dump); 83 static void remove_thread_dump(ThreadDumpResult* dump); 84 85 static Handle get_current_contended_monitor(JavaThread* thread); 86 87 // This function is called by JVM_DumpThreads. 88 static Handle dump_stack_traces(GrowableArray<instanceHandle>* threads, 89 int num_threads, TRAPS); 90 91 static void reset_peak_thread_count(); 92 static void reset_contention_count_stat(JavaThread* thread); 93 static void reset_contention_time_stat(JavaThread* thread); 94 95 static DeadlockCycle* find_deadlocks_at_safepoint(bool object_monitors_only); 96 97 // GC support 98 static void oops_do(OopClosure* f); 99}; 100 101// Per-thread Statistics for synchronization 102class ThreadStatistics : public CHeapObj { 103private: 104 // The following contention statistics are only updated by 105 // the thread owning these statistics when contention occurs. 106 107 jlong _contended_enter_count; 108 elapsedTimer _contended_enter_timer; 109 jlong _monitor_wait_count; 110 elapsedTimer _monitor_wait_timer; 111 jlong _sleep_count; 112 elapsedTimer _sleep_timer; 113 114 115 // These two reset flags are set to true when another thread 116 // requests to reset the statistics. The actual statistics 117 // are reset when the thread contention occurs and attempts 118 // to update the statistics. 119 bool _count_pending_reset; 120 bool _timer_pending_reset; 121 122 // Keep accurate times for potentially recursive class operations 123 int _class_init_recursion_count; 124 int _class_verify_recursion_count; 125 int _class_link_recursion_count; 126 127 // utility functions 128 void check_and_reset_count() { 129 if (!_count_pending_reset) return; 130 _contended_enter_count = 0; 131 _monitor_wait_count = 0; 132 _sleep_count = 0; 133 _count_pending_reset = 0; 134 } 135 void check_and_reset_timer() { 136 if (!_timer_pending_reset) return; 137 _contended_enter_timer.reset(); 138 _monitor_wait_timer.reset(); 139 _sleep_timer.reset(); 140 _timer_pending_reset = 0; 141 } 142 143public: 144 ThreadStatistics(); 145 146 jlong contended_enter_count() { return (_count_pending_reset ? 0 : _contended_enter_count); } 147 jlong contended_enter_ticks() { return (_timer_pending_reset ? 0 : _contended_enter_timer.active_ticks()); } 148 jlong monitor_wait_count() { return (_count_pending_reset ? 0 : _monitor_wait_count); } 149 jlong monitor_wait_ticks() { return (_timer_pending_reset ? 0 : _monitor_wait_timer.active_ticks()); } 150 jlong sleep_count() { return (_count_pending_reset ? 0 : _sleep_count); } 151 jlong sleep_ticks() { return (_timer_pending_reset ? 0 : _sleep_timer.active_ticks()); } 152 153 void monitor_wait() { check_and_reset_count(); _monitor_wait_count++; } 154 void monitor_wait_begin() { check_and_reset_timer(); _monitor_wait_timer.start(); } 155 void monitor_wait_end() { _monitor_wait_timer.stop(); check_and_reset_timer(); } 156 157 void thread_sleep() { check_and_reset_count(); _sleep_count++; } 158 void thread_sleep_begin() { check_and_reset_timer(); _sleep_timer.start(); } 159 void thread_sleep_end() { _sleep_timer.stop(); check_and_reset_timer(); } 160 161 void contended_enter() { check_and_reset_count(); _contended_enter_count++; } 162 void contended_enter_begin() { check_and_reset_timer(); _contended_enter_timer.start(); } 163 void contended_enter_end() { _contended_enter_timer.stop(); check_and_reset_timer(); } 164 165 void reset_count_stat() { _count_pending_reset = true; } 166 void reset_time_stat() { _timer_pending_reset = true; } 167 168 int* class_init_recursion_count_addr() { return &_class_init_recursion_count; } 169 int* class_verify_recursion_count_addr() { return &_class_verify_recursion_count; } 170 int* class_link_recursion_count_addr() { return &_class_link_recursion_count; } 171}; 172 173// Thread snapshot to represent the thread state and statistics 174class ThreadSnapshot : public CHeapObj { 175private: 176 JavaThread* _thread; 177 oop _threadObj; 178 java_lang_Thread::ThreadStatus _thread_status; 179 180 bool _is_ext_suspended; 181 bool _is_in_native; 182 183 jlong _contended_enter_ticks; 184 jlong _contended_enter_count; 185 jlong _monitor_wait_ticks; 186 jlong _monitor_wait_count; 187 jlong _sleep_ticks; 188 jlong _sleep_count; 189 oop _blocker_object; 190 oop _blocker_object_owner; 191 192 ThreadStackTrace* _stack_trace; 193 ThreadConcurrentLocks* _concurrent_locks; 194 ThreadSnapshot* _next; 195 196public: 197 // Dummy snapshot 198 ThreadSnapshot() : _thread(NULL), _threadObj(NULL), _stack_trace(NULL), _concurrent_locks(NULL), _next(NULL), 199 _blocker_object(NULL), _blocker_object_owner(NULL) {}; 200 ThreadSnapshot(JavaThread* thread); 201 ~ThreadSnapshot(); 202 203 java_lang_Thread::ThreadStatus thread_status() { return _thread_status; } 204 205 oop threadObj() const { return _threadObj; } 206 207 void set_next(ThreadSnapshot* n) { _next = n; } 208 209 bool is_ext_suspended() { return _is_ext_suspended; } 210 bool is_in_native() { return _is_in_native; } 211 212 jlong contended_enter_count() { return _contended_enter_count; } 213 jlong contended_enter_ticks() { return _contended_enter_ticks; } 214 jlong monitor_wait_count() { return _monitor_wait_count; } 215 jlong monitor_wait_ticks() { return _monitor_wait_ticks; } 216 jlong sleep_count() { return _sleep_count; } 217 jlong sleep_ticks() { return _sleep_ticks; } 218 219 220 oop blocker_object() { return _blocker_object; } 221 oop blocker_object_owner() { return _blocker_object_owner; } 222 223 ThreadSnapshot* next() const { return _next; } 224 ThreadStackTrace* get_stack_trace() { return _stack_trace; } 225 ThreadConcurrentLocks* get_concurrent_locks() { return _concurrent_locks; } 226 227 void dump_stack_at_safepoint(int max_depth, bool with_locked_monitors); 228 void set_concurrent_locks(ThreadConcurrentLocks* l) { _concurrent_locks = l; } 229 void oops_do(OopClosure* f); 230}; 231 232class ThreadStackTrace : public CHeapObj { 233 private: 234 JavaThread* _thread; 235 int _depth; // number of stack frames added 236 bool _with_locked_monitors; 237 GrowableArray<StackFrameInfo*>* _frames; 238 GrowableArray<oop>* _jni_locked_monitors; 239 240 public: 241 242 ThreadStackTrace(JavaThread* thread, bool with_locked_monitors); 243 ~ThreadStackTrace(); 244 245 StackFrameInfo* stack_frame_at(int i) { return _frames->at(i); } 246 int get_stack_depth() { return _depth; } 247 248 void add_stack_frame(javaVFrame* jvf); 249 void dump_stack_at_safepoint(int max_depth); 250 Handle allocate_fill_stack_trace_element_array(TRAPS); 251 void oops_do(OopClosure* f); 252 GrowableArray<oop>* jni_locked_monitors() { return _jni_locked_monitors; } 253 int num_jni_locked_monitors() { return (_jni_locked_monitors != NULL ? _jni_locked_monitors->length() : 0); } 254 255 bool is_owned_monitor_on_stack(oop object); 256 void add_jni_locked_monitor(oop object) { _jni_locked_monitors->append(object); } 257}; 258 259// StackFrameInfo for keeping methodOop and bci during 260// stack walking for later construction of StackTraceElement[] 261// Java instances 262class StackFrameInfo : public CHeapObj { 263 private: 264 methodOop _method; 265 int _bci; 266 GrowableArray<oop>* _locked_monitors; // list of object monitors locked by this frame 267 268 public: 269 270 StackFrameInfo(javaVFrame* jvf, bool with_locked_monitors); 271 ~StackFrameInfo() { 272 if (_locked_monitors != NULL) { 273 delete _locked_monitors; 274 } 275 }; 276 methodOop method() const { return _method; } 277 int bci() const { return _bci; } 278 void oops_do(OopClosure* f); 279 280 int num_locked_monitors() { return (_locked_monitors != NULL ? _locked_monitors->length() : 0); } 281 GrowableArray<oop>* locked_monitors() { return _locked_monitors; } 282 283 void print_on(outputStream* st) const; 284}; 285 286class ThreadConcurrentLocks : public CHeapObj { 287private: 288 GrowableArray<instanceOop>* _owned_locks; 289 ThreadConcurrentLocks* _next; 290 JavaThread* _thread; 291 public: 292 ThreadConcurrentLocks(JavaThread* thread); 293 ~ThreadConcurrentLocks(); 294 295 void add_lock(instanceOop o); 296 void set_next(ThreadConcurrentLocks* n) { _next = n; } 297 ThreadConcurrentLocks* next() { return _next; } 298 JavaThread* java_thread() { return _thread; } 299 GrowableArray<instanceOop>* owned_locks() { return _owned_locks; } 300 void oops_do(OopClosure* f); 301}; 302 303class ConcurrentLocksDump : public StackObj { 304 private: 305 ThreadConcurrentLocks* _map; 306 ThreadConcurrentLocks* _last; // Last ThreadConcurrentLocks in the map 307 bool _retain_map_on_free; 308 309 void build_map(GrowableArray<oop>* aos_objects); 310 void add_lock(JavaThread* thread, instanceOop o); 311 312 public: 313 ConcurrentLocksDump(bool retain_map_on_free) : _map(NULL), _last(NULL), _retain_map_on_free(retain_map_on_free) {}; 314 ConcurrentLocksDump() : _map(NULL), _last(NULL), _retain_map_on_free(false) {}; 315 ~ConcurrentLocksDump(); 316 317 void dump_at_safepoint(); 318 ThreadConcurrentLocks* thread_concurrent_locks(JavaThread* thread); 319 void print_locks_on(JavaThread* t, outputStream* st); 320}; 321 322class ThreadDumpResult : public StackObj { 323 private: 324 int _num_threads; 325 int _num_snapshots; 326 ThreadSnapshot* _snapshots; 327 ThreadSnapshot* _last; 328 ThreadDumpResult* _next; 329 public: 330 ThreadDumpResult(); 331 ThreadDumpResult(int num_threads); 332 ~ThreadDumpResult(); 333 334 void add_thread_snapshot(ThreadSnapshot* ts); 335 void set_next(ThreadDumpResult* next) { _next = next; } 336 ThreadDumpResult* next() { return _next; } 337 int num_threads() { return _num_threads; } 338 int num_snapshots() { return _num_snapshots; } 339 ThreadSnapshot* snapshots() { return _snapshots; } 340 void oops_do(OopClosure* f); 341}; 342 343class DeadlockCycle : public CHeapObj { 344 private: 345 bool _is_deadlock; 346 GrowableArray<JavaThread*>* _threads; 347 DeadlockCycle* _next; 348 public: 349 DeadlockCycle(); 350 ~DeadlockCycle(); 351 352 DeadlockCycle* next() { return _next; } 353 void set_next(DeadlockCycle* d) { _next = d; } 354 void add_thread(JavaThread* t) { _threads->append(t); } 355 void reset() { _is_deadlock = false; _threads->clear(); } 356 void set_deadlock(bool value) { _is_deadlock = value; } 357 bool is_deadlock() { return _is_deadlock; } 358 int num_threads() { return _threads->length(); } 359 GrowableArray<JavaThread*>* threads() { return _threads; } 360 void print_on(outputStream* st) const; 361}; 362 363// Utility class to get list of java threads. 364class ThreadsListEnumerator : public StackObj { 365private: 366 GrowableArray<instanceHandle>* _threads_array; 367public: 368 ThreadsListEnumerator(Thread* cur_thread, 369 bool include_jvmti_agent_threads = false, 370 bool include_jni_attaching_threads = true); 371 int num_threads() { return _threads_array->length(); } 372 instanceHandle get_threadObj(int index) { return _threads_array->at(index); } 373}; 374 375 376// abstract utility class to set new thread states, and restore previous after the block exits 377class JavaThreadStatusChanger : public StackObj { 378 private: 379 java_lang_Thread::ThreadStatus _old_state; 380 JavaThread* _java_thread; 381 bool _is_alive; 382 383 void save_old_state(JavaThread* java_thread) { 384 _java_thread = java_thread; 385 _is_alive = is_alive(java_thread); 386 if (is_alive()) { 387 _old_state = java_lang_Thread::get_thread_status(_java_thread->threadObj()); 388 } 389 } 390 391 public: 392 static void set_thread_status(JavaThread* java_thread, 393 java_lang_Thread::ThreadStatus state) { 394 java_lang_Thread::set_thread_status(java_thread->threadObj(), state); 395 } 396 397 void set_thread_status(java_lang_Thread::ThreadStatus state) { 398 if (is_alive()) { 399 set_thread_status(_java_thread, state); 400 } 401 } 402 403 JavaThreadStatusChanger(JavaThread* java_thread, 404 java_lang_Thread::ThreadStatus state) { 405 save_old_state(java_thread); 406 set_thread_status(state); 407 } 408 409 JavaThreadStatusChanger(JavaThread* java_thread) { 410 save_old_state(java_thread); 411 } 412 413 ~JavaThreadStatusChanger() { 414 set_thread_status(_old_state); 415 } 416 417 static bool is_alive(JavaThread* java_thread) { 418 return java_thread != NULL && java_thread->threadObj() != NULL; 419 } 420 421 bool is_alive() { 422 return _is_alive; 423 } 424}; 425 426// Change status to waiting on an object (timed or indefinite) 427class JavaThreadInObjectWaitState : public JavaThreadStatusChanger { 428 private: 429 ThreadStatistics* _stat; 430 bool _active; 431 432 public: 433 JavaThreadInObjectWaitState(JavaThread *java_thread, bool timed) : 434 JavaThreadStatusChanger(java_thread, 435 timed ? java_lang_Thread::IN_OBJECT_WAIT_TIMED : java_lang_Thread::IN_OBJECT_WAIT) { 436 if (is_alive()) { 437 _stat = java_thread->get_thread_stat(); 438 _active = ThreadService::is_thread_monitoring_contention(); 439 _stat->monitor_wait(); 440 if (_active) { 441 _stat->monitor_wait_begin(); 442 } 443 } else { 444 _active = false; 445 } 446 } 447 448 ~JavaThreadInObjectWaitState() { 449 if (_active) { 450 _stat->monitor_wait_end(); 451 } 452 } 453}; 454 455// Change status to parked (timed or indefinite) 456class JavaThreadParkedState : public JavaThreadStatusChanger { 457 private: 458 ThreadStatistics* _stat; 459 bool _active; 460 461 public: 462 JavaThreadParkedState(JavaThread *java_thread, bool timed) : 463 JavaThreadStatusChanger(java_thread, 464 timed ? java_lang_Thread::PARKED_TIMED : java_lang_Thread::PARKED) { 465 if (is_alive()) { 466 _stat = java_thread->get_thread_stat(); 467 _active = ThreadService::is_thread_monitoring_contention(); 468 _stat->monitor_wait(); 469 if (_active) { 470 _stat->monitor_wait_begin(); 471 } 472 } else { 473 _active = false; 474 } 475 } 476 477 ~JavaThreadParkedState() { 478 if (_active) { 479 _stat->monitor_wait_end(); 480 } 481 } 482}; 483 484// Change status to blocked on (re-)entering a synchronization block 485class JavaThreadBlockedOnMonitorEnterState : public JavaThreadStatusChanger { 486 private: 487 ThreadStatistics* _stat; 488 bool _active; 489 490 static bool contended_enter_begin(JavaThread *java_thread) { 491 set_thread_status(java_thread, java_lang_Thread::BLOCKED_ON_MONITOR_ENTER); 492 ThreadStatistics* stat = java_thread->get_thread_stat(); 493 stat->contended_enter(); 494 bool active = ThreadService::is_thread_monitoring_contention(); 495 if (active) { 496 stat->contended_enter_begin(); 497 } 498 return active; 499 } 500 501 public: 502 // java_thread is waiting thread being blocked on monitor reenter. 503 // Current thread is the notifying thread which holds the monitor. 504 static bool wait_reenter_begin(JavaThread *java_thread, ObjectMonitor *obj_m) { 505 assert((java_thread != NULL), "Java thread should not be null here"); 506 bool active = false; 507 if (is_alive(java_thread) && ServiceUtil::visible_oop((oop)obj_m->object())) { 508 active = contended_enter_begin(java_thread); 509 } 510 return active; 511 } 512 513 static void wait_reenter_end(JavaThread *java_thread, bool active) { 514 if (active) { 515 java_thread->get_thread_stat()->contended_enter_end(); 516 } 517 set_thread_status(java_thread, java_lang_Thread::RUNNABLE); 518 } 519 520 JavaThreadBlockedOnMonitorEnterState(JavaThread *java_thread, ObjectMonitor *obj_m) : 521 JavaThreadStatusChanger(java_thread) { 522 assert((java_thread != NULL), "Java thread should not be null here"); 523 // Change thread status and collect contended enter stats for monitor contended 524 // enter done for external java world objects and it is contended. All other cases 525 // like for vm internal objects and for external objects which are not contended 526 // thread status is not changed and contended enter stat is not collected. 527 _active = false; 528 if (is_alive() && ServiceUtil::visible_oop((oop)obj_m->object()) && obj_m->contentions() > 0) { 529 _stat = java_thread->get_thread_stat(); 530 _active = contended_enter_begin(java_thread); 531 } 532 } 533 534 ~JavaThreadBlockedOnMonitorEnterState() { 535 if (_active) { 536 _stat->contended_enter_end(); 537 } 538 } 539}; 540 541// Change status to sleeping 542class JavaThreadSleepState : public JavaThreadStatusChanger { 543 private: 544 ThreadStatistics* _stat; 545 bool _active; 546 public: 547 JavaThreadSleepState(JavaThread *java_thread) : 548 JavaThreadStatusChanger(java_thread, java_lang_Thread::SLEEPING) { 549 if (is_alive()) { 550 _stat = java_thread->get_thread_stat(); 551 _active = ThreadService::is_thread_monitoring_contention(); 552 _stat->thread_sleep(); 553 if (_active) { 554 _stat->thread_sleep_begin(); 555 } 556 } else { 557 _active = false; 558 } 559 } 560 561 ~JavaThreadSleepState() { 562 if (_active) { 563 _stat->thread_sleep_end(); 564 } 565 } 566}; 567