Tue, 09 Oct 2012 10:09:34 -0700
7197424: update copyright year to match last edit in jdk8 hotspot repository
Summary: Update copyright year to 2012 for relevant files
Reviewed-by: dholmes, coleenp
1 /*
2 * Copyright (c) 2003, 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 */
25 #ifndef SHARE_VM_SERVICES_THREADSERVICE_HPP
26 #define SHARE_VM_SERVICES_THREADSERVICE_HPP
28 #include "classfile/javaClasses.hpp"
29 #include "runtime/handles.hpp"
30 #include "runtime/init.hpp"
31 #include "runtime/jniHandles.hpp"
32 #include "runtime/objectMonitor.hpp"
33 #include "runtime/objectMonitor.inline.hpp"
34 #include "runtime/perfData.hpp"
35 #include "services/management.hpp"
36 #include "services/serviceUtil.hpp"
38 class OopClosure;
39 class ThreadDumpResult;
40 class ThreadStackTrace;
41 class ThreadSnapshot;
42 class StackFrameInfo;
43 class ThreadConcurrentLocks;
44 class DeadlockCycle;
46 // VM monitoring and management support for the thread and
47 // synchronization subsystem
48 //
49 // Thread contention monitoring is disabled by default.
50 // When enabled, the VM will begin measuring the accumulated
51 // elapsed time a thread blocked on synchronization.
52 //
53 class ThreadService : public AllStatic {
54 private:
55 // These counters could be moved to Threads class
56 static PerfCounter* _total_threads_count;
57 static PerfVariable* _live_threads_count;
58 static PerfVariable* _peak_threads_count;
59 static PerfVariable* _daemon_threads_count;
61 // These 2 counters are atomically incremented once the thread is exiting.
62 // They will be atomically decremented when ThreadService::remove_thread is called.
63 static volatile int _exiting_threads_count;
64 static volatile int _exiting_daemon_threads_count;
66 static bool _thread_monitoring_contention_enabled;
67 static bool _thread_cpu_time_enabled;
68 static bool _thread_allocated_memory_enabled;
70 // Need to keep the list of thread dump result that
71 // keep references to Method* since thread dump can be
72 // requested by multiple threads concurrently.
73 static ThreadDumpResult* _threaddump_list;
75 public:
76 static void init();
77 static void add_thread(JavaThread* thread, bool daemon);
78 static void remove_thread(JavaThread* thread, bool daemon);
79 static void current_thread_exiting(JavaThread* jt);
81 static bool set_thread_monitoring_contention(bool flag);
82 static bool is_thread_monitoring_contention() { return _thread_monitoring_contention_enabled; }
84 static bool set_thread_cpu_time_enabled(bool flag);
85 static bool is_thread_cpu_time_enabled() { return _thread_cpu_time_enabled; }
87 static bool set_thread_allocated_memory_enabled(bool flag);
88 static bool is_thread_allocated_memory_enabled() { return _thread_cpu_time_enabled; }
90 static jlong get_total_thread_count() { return _total_threads_count->get_value(); }
91 static jlong get_peak_thread_count() { return _peak_threads_count->get_value(); }
92 static jlong get_live_thread_count() { return _live_threads_count->get_value() - _exiting_threads_count; }
93 static jlong get_daemon_thread_count() { return _daemon_threads_count->get_value() - _exiting_daemon_threads_count; }
95 static int exiting_threads_count() { return _exiting_threads_count; }
96 static int exiting_daemon_threads_count() { return _exiting_daemon_threads_count; }
98 // Support for thread dump
99 static void add_thread_dump(ThreadDumpResult* dump);
100 static void remove_thread_dump(ThreadDumpResult* dump);
102 static Handle get_current_contended_monitor(JavaThread* thread);
104 // This function is called by JVM_DumpThreads.
105 static Handle dump_stack_traces(GrowableArray<instanceHandle>* threads,
106 int num_threads, TRAPS);
108 static void reset_peak_thread_count();
109 static void reset_contention_count_stat(JavaThread* thread);
110 static void reset_contention_time_stat(JavaThread* thread);
112 static DeadlockCycle* find_deadlocks_at_safepoint(bool object_monitors_only);
114 // GC support
115 static void oops_do(OopClosure* f);
116 };
118 // Per-thread Statistics for synchronization
119 class ThreadStatistics : public CHeapObj<mtInternal> {
120 private:
121 // The following contention statistics are only updated by
122 // the thread owning these statistics when contention occurs.
124 jlong _contended_enter_count;
125 elapsedTimer _contended_enter_timer;
126 jlong _monitor_wait_count;
127 elapsedTimer _monitor_wait_timer;
128 jlong _sleep_count;
129 elapsedTimer _sleep_timer;
132 // These two reset flags are set to true when another thread
133 // requests to reset the statistics. The actual statistics
134 // are reset when the thread contention occurs and attempts
135 // to update the statistics.
136 bool _count_pending_reset;
137 bool _timer_pending_reset;
139 // Keep accurate times for potentially recursive class operations
140 int _perf_recursion_counts[6];
141 elapsedTimer _perf_timers[6];
143 // utility functions
144 void check_and_reset_count() {
145 if (!_count_pending_reset) return;
146 _contended_enter_count = 0;
147 _monitor_wait_count = 0;
148 _sleep_count = 0;
149 _count_pending_reset = 0;
150 }
151 void check_and_reset_timer() {
152 if (!_timer_pending_reset) return;
153 _contended_enter_timer.reset();
154 _monitor_wait_timer.reset();
155 _sleep_timer.reset();
156 _timer_pending_reset = 0;
157 }
159 public:
160 ThreadStatistics();
162 jlong contended_enter_count() { return (_count_pending_reset ? 0 : _contended_enter_count); }
163 jlong contended_enter_ticks() { return (_timer_pending_reset ? 0 : _contended_enter_timer.active_ticks()); }
164 jlong monitor_wait_count() { return (_count_pending_reset ? 0 : _monitor_wait_count); }
165 jlong monitor_wait_ticks() { return (_timer_pending_reset ? 0 : _monitor_wait_timer.active_ticks()); }
166 jlong sleep_count() { return (_count_pending_reset ? 0 : _sleep_count); }
167 jlong sleep_ticks() { return (_timer_pending_reset ? 0 : _sleep_timer.active_ticks()); }
169 void monitor_wait() { check_and_reset_count(); _monitor_wait_count++; }
170 void monitor_wait_begin() { check_and_reset_timer(); _monitor_wait_timer.start(); }
171 void monitor_wait_end() { _monitor_wait_timer.stop(); check_and_reset_timer(); }
173 void thread_sleep() { check_and_reset_count(); _sleep_count++; }
174 void thread_sleep_begin() { check_and_reset_timer(); _sleep_timer.start(); }
175 void thread_sleep_end() { _sleep_timer.stop(); check_and_reset_timer(); }
177 void contended_enter() { check_and_reset_count(); _contended_enter_count++; }
178 void contended_enter_begin() { check_and_reset_timer(); _contended_enter_timer.start(); }
179 void contended_enter_end() { _contended_enter_timer.stop(); check_and_reset_timer(); }
181 void reset_count_stat() { _count_pending_reset = true; }
182 void reset_time_stat() { _timer_pending_reset = true; }
184 int* perf_recursion_counts_addr() { return _perf_recursion_counts; }
185 elapsedTimer* perf_timers_addr() { return _perf_timers; }
186 };
188 // Thread snapshot to represent the thread state and statistics
189 class ThreadSnapshot : public CHeapObj<mtInternal> {
190 private:
191 JavaThread* _thread;
192 oop _threadObj;
193 java_lang_Thread::ThreadStatus _thread_status;
195 bool _is_ext_suspended;
196 bool _is_in_native;
198 jlong _contended_enter_ticks;
199 jlong _contended_enter_count;
200 jlong _monitor_wait_ticks;
201 jlong _monitor_wait_count;
202 jlong _sleep_ticks;
203 jlong _sleep_count;
204 oop _blocker_object;
205 oop _blocker_object_owner;
207 ThreadStackTrace* _stack_trace;
208 ThreadConcurrentLocks* _concurrent_locks;
209 ThreadSnapshot* _next;
211 public:
212 // Dummy snapshot
213 ThreadSnapshot() : _thread(NULL), _threadObj(NULL), _stack_trace(NULL), _concurrent_locks(NULL), _next(NULL),
214 _blocker_object(NULL), _blocker_object_owner(NULL) {};
215 ThreadSnapshot(JavaThread* thread);
216 ~ThreadSnapshot();
218 java_lang_Thread::ThreadStatus thread_status() { return _thread_status; }
220 oop threadObj() const { return _threadObj; }
222 void set_next(ThreadSnapshot* n) { _next = n; }
224 bool is_ext_suspended() { return _is_ext_suspended; }
225 bool is_in_native() { return _is_in_native; }
227 jlong contended_enter_count() { return _contended_enter_count; }
228 jlong contended_enter_ticks() { return _contended_enter_ticks; }
229 jlong monitor_wait_count() { return _monitor_wait_count; }
230 jlong monitor_wait_ticks() { return _monitor_wait_ticks; }
231 jlong sleep_count() { return _sleep_count; }
232 jlong sleep_ticks() { return _sleep_ticks; }
235 oop blocker_object() { return _blocker_object; }
236 oop blocker_object_owner() { return _blocker_object_owner; }
238 ThreadSnapshot* next() const { return _next; }
239 ThreadStackTrace* get_stack_trace() { return _stack_trace; }
240 ThreadConcurrentLocks* get_concurrent_locks() { return _concurrent_locks; }
242 void dump_stack_at_safepoint(int max_depth, bool with_locked_monitors);
243 void set_concurrent_locks(ThreadConcurrentLocks* l) { _concurrent_locks = l; }
244 void oops_do(OopClosure* f);
245 };
247 class ThreadStackTrace : public CHeapObj<mtInternal> {
248 private:
249 JavaThread* _thread;
250 int _depth; // number of stack frames added
251 bool _with_locked_monitors;
252 GrowableArray<StackFrameInfo*>* _frames;
253 GrowableArray<oop>* _jni_locked_monitors;
255 public:
257 ThreadStackTrace(JavaThread* thread, bool with_locked_monitors);
258 ~ThreadStackTrace();
260 JavaThread* thread() { return _thread; }
261 StackFrameInfo* stack_frame_at(int i) { return _frames->at(i); }
262 int get_stack_depth() { return _depth; }
264 void add_stack_frame(javaVFrame* jvf);
265 void dump_stack_at_safepoint(int max_depth);
266 Handle allocate_fill_stack_trace_element_array(TRAPS);
267 void oops_do(OopClosure* f);
268 GrowableArray<oop>* jni_locked_monitors() { return _jni_locked_monitors; }
269 int num_jni_locked_monitors() { return (_jni_locked_monitors != NULL ? _jni_locked_monitors->length() : 0); }
271 bool is_owned_monitor_on_stack(oop object);
272 void add_jni_locked_monitor(oop object) { _jni_locked_monitors->append(object); }
273 };
275 // StackFrameInfo for keeping Method* and bci during
276 // stack walking for later construction of StackTraceElement[]
277 // Java instances
278 class StackFrameInfo : public CHeapObj<mtInternal> {
279 private:
280 Method* _method;
281 int _bci;
282 GrowableArray<oop>* _locked_monitors; // list of object monitors locked by this frame
284 public:
286 StackFrameInfo(javaVFrame* jvf, bool with_locked_monitors);
287 ~StackFrameInfo() {
288 if (_locked_monitors != NULL) {
289 delete _locked_monitors;
290 }
291 };
292 Method* method() const { return _method; }
293 int bci() const { return _bci; }
294 void oops_do(OopClosure* f);
296 int num_locked_monitors() { return (_locked_monitors != NULL ? _locked_monitors->length() : 0); }
297 GrowableArray<oop>* locked_monitors() { return _locked_monitors; }
299 void print_on(outputStream* st) const;
300 };
302 class ThreadConcurrentLocks : public CHeapObj<mtInternal> {
303 private:
304 GrowableArray<instanceOop>* _owned_locks;
305 ThreadConcurrentLocks* _next;
306 JavaThread* _thread;
307 public:
308 ThreadConcurrentLocks(JavaThread* thread);
309 ~ThreadConcurrentLocks();
311 void add_lock(instanceOop o);
312 void set_next(ThreadConcurrentLocks* n) { _next = n; }
313 ThreadConcurrentLocks* next() { return _next; }
314 JavaThread* java_thread() { return _thread; }
315 GrowableArray<instanceOop>* owned_locks() { return _owned_locks; }
316 void oops_do(OopClosure* f);
317 };
319 class ConcurrentLocksDump : public StackObj {
320 private:
321 ThreadConcurrentLocks* _map;
322 ThreadConcurrentLocks* _last; // Last ThreadConcurrentLocks in the map
323 bool _retain_map_on_free;
325 void build_map(GrowableArray<oop>* aos_objects);
326 void add_lock(JavaThread* thread, instanceOop o);
328 public:
329 ConcurrentLocksDump(bool retain_map_on_free) : _map(NULL), _last(NULL), _retain_map_on_free(retain_map_on_free) {};
330 ConcurrentLocksDump() : _map(NULL), _last(NULL), _retain_map_on_free(false) {};
331 ~ConcurrentLocksDump();
333 void dump_at_safepoint();
334 ThreadConcurrentLocks* thread_concurrent_locks(JavaThread* thread);
335 void print_locks_on(JavaThread* t, outputStream* st);
336 };
338 class ThreadDumpResult : public StackObj {
339 private:
340 int _num_threads;
341 int _num_snapshots;
342 ThreadSnapshot* _snapshots;
343 ThreadSnapshot* _last;
344 ThreadDumpResult* _next;
345 public:
346 ThreadDumpResult();
347 ThreadDumpResult(int num_threads);
348 ~ThreadDumpResult();
350 void add_thread_snapshot(ThreadSnapshot* ts);
351 void set_next(ThreadDumpResult* next) { _next = next; }
352 ThreadDumpResult* next() { return _next; }
353 int num_threads() { return _num_threads; }
354 int num_snapshots() { return _num_snapshots; }
355 ThreadSnapshot* snapshots() { return _snapshots; }
356 void oops_do(OopClosure* f);
357 };
359 class DeadlockCycle : public CHeapObj<mtInternal> {
360 private:
361 bool _is_deadlock;
362 GrowableArray<JavaThread*>* _threads;
363 DeadlockCycle* _next;
364 public:
365 DeadlockCycle();
366 ~DeadlockCycle();
368 DeadlockCycle* next() { return _next; }
369 void set_next(DeadlockCycle* d) { _next = d; }
370 void add_thread(JavaThread* t) { _threads->append(t); }
371 void reset() { _is_deadlock = false; _threads->clear(); }
372 void set_deadlock(bool value) { _is_deadlock = value; }
373 bool is_deadlock() { return _is_deadlock; }
374 int num_threads() { return _threads->length(); }
375 GrowableArray<JavaThread*>* threads() { return _threads; }
376 void print_on(outputStream* st) const;
377 };
379 // Utility class to get list of java threads.
380 class ThreadsListEnumerator : public StackObj {
381 private:
382 GrowableArray<instanceHandle>* _threads_array;
383 public:
384 ThreadsListEnumerator(Thread* cur_thread,
385 bool include_jvmti_agent_threads = false,
386 bool include_jni_attaching_threads = true);
387 int num_threads() { return _threads_array->length(); }
388 instanceHandle get_threadObj(int index) { return _threads_array->at(index); }
389 };
392 // abstract utility class to set new thread states, and restore previous after the block exits
393 class JavaThreadStatusChanger : public StackObj {
394 private:
395 java_lang_Thread::ThreadStatus _old_state;
396 JavaThread* _java_thread;
397 bool _is_alive;
399 void save_old_state(JavaThread* java_thread) {
400 _java_thread = java_thread;
401 _is_alive = is_alive(java_thread);
402 if (is_alive()) {
403 _old_state = java_lang_Thread::get_thread_status(_java_thread->threadObj());
404 }
405 }
407 public:
408 static void set_thread_status(JavaThread* java_thread,
409 java_lang_Thread::ThreadStatus state) {
410 java_lang_Thread::set_thread_status(java_thread->threadObj(), state);
411 }
413 void set_thread_status(java_lang_Thread::ThreadStatus state) {
414 if (is_alive()) {
415 set_thread_status(_java_thread, state);
416 }
417 }
419 JavaThreadStatusChanger(JavaThread* java_thread,
420 java_lang_Thread::ThreadStatus state) {
421 save_old_state(java_thread);
422 set_thread_status(state);
423 }
425 JavaThreadStatusChanger(JavaThread* java_thread) {
426 save_old_state(java_thread);
427 }
429 ~JavaThreadStatusChanger() {
430 set_thread_status(_old_state);
431 }
433 static bool is_alive(JavaThread* java_thread) {
434 return java_thread != NULL && java_thread->threadObj() != NULL;
435 }
437 bool is_alive() {
438 return _is_alive;
439 }
440 };
442 // Change status to waiting on an object (timed or indefinite)
443 class JavaThreadInObjectWaitState : public JavaThreadStatusChanger {
444 private:
445 ThreadStatistics* _stat;
446 bool _active;
448 public:
449 JavaThreadInObjectWaitState(JavaThread *java_thread, bool timed) :
450 JavaThreadStatusChanger(java_thread,
451 timed ? java_lang_Thread::IN_OBJECT_WAIT_TIMED : java_lang_Thread::IN_OBJECT_WAIT) {
452 if (is_alive()) {
453 _stat = java_thread->get_thread_stat();
454 _active = ThreadService::is_thread_monitoring_contention();
455 _stat->monitor_wait();
456 if (_active) {
457 _stat->monitor_wait_begin();
458 }
459 } else {
460 _active = false;
461 }
462 }
464 ~JavaThreadInObjectWaitState() {
465 if (_active) {
466 _stat->monitor_wait_end();
467 }
468 }
469 };
471 // Change status to parked (timed or indefinite)
472 class JavaThreadParkedState : public JavaThreadStatusChanger {
473 private:
474 ThreadStatistics* _stat;
475 bool _active;
477 public:
478 JavaThreadParkedState(JavaThread *java_thread, bool timed) :
479 JavaThreadStatusChanger(java_thread,
480 timed ? java_lang_Thread::PARKED_TIMED : java_lang_Thread::PARKED) {
481 if (is_alive()) {
482 _stat = java_thread->get_thread_stat();
483 _active = ThreadService::is_thread_monitoring_contention();
484 _stat->monitor_wait();
485 if (_active) {
486 _stat->monitor_wait_begin();
487 }
488 } else {
489 _active = false;
490 }
491 }
493 ~JavaThreadParkedState() {
494 if (_active) {
495 _stat->monitor_wait_end();
496 }
497 }
498 };
500 // Change status to blocked on (re-)entering a synchronization block
501 class JavaThreadBlockedOnMonitorEnterState : public JavaThreadStatusChanger {
502 private:
503 ThreadStatistics* _stat;
504 bool _active;
506 static bool contended_enter_begin(JavaThread *java_thread) {
507 set_thread_status(java_thread, java_lang_Thread::BLOCKED_ON_MONITOR_ENTER);
508 ThreadStatistics* stat = java_thread->get_thread_stat();
509 stat->contended_enter();
510 bool active = ThreadService::is_thread_monitoring_contention();
511 if (active) {
512 stat->contended_enter_begin();
513 }
514 return active;
515 }
517 public:
518 // java_thread is waiting thread being blocked on monitor reenter.
519 // Current thread is the notifying thread which holds the monitor.
520 static bool wait_reenter_begin(JavaThread *java_thread, ObjectMonitor *obj_m) {
521 assert((java_thread != NULL), "Java thread should not be null here");
522 bool active = false;
523 if (is_alive(java_thread) && ServiceUtil::visible_oop((oop)obj_m->object())) {
524 active = contended_enter_begin(java_thread);
525 }
526 return active;
527 }
529 static void wait_reenter_end(JavaThread *java_thread, bool active) {
530 if (active) {
531 java_thread->get_thread_stat()->contended_enter_end();
532 }
533 set_thread_status(java_thread, java_lang_Thread::RUNNABLE);
534 }
536 JavaThreadBlockedOnMonitorEnterState(JavaThread *java_thread, ObjectMonitor *obj_m) :
537 JavaThreadStatusChanger(java_thread) {
538 assert((java_thread != NULL), "Java thread should not be null here");
539 // Change thread status and collect contended enter stats for monitor contended
540 // enter done for external java world objects and it is contended. All other cases
541 // like for vm internal objects and for external objects which are not contended
542 // thread status is not changed and contended enter stat is not collected.
543 _active = false;
544 if (is_alive() && ServiceUtil::visible_oop((oop)obj_m->object()) && obj_m->contentions() > 0) {
545 _stat = java_thread->get_thread_stat();
546 _active = contended_enter_begin(java_thread);
547 }
548 }
550 ~JavaThreadBlockedOnMonitorEnterState() {
551 if (_active) {
552 _stat->contended_enter_end();
553 }
554 }
555 };
557 // Change status to sleeping
558 class JavaThreadSleepState : public JavaThreadStatusChanger {
559 private:
560 ThreadStatistics* _stat;
561 bool _active;
562 public:
563 JavaThreadSleepState(JavaThread *java_thread) :
564 JavaThreadStatusChanger(java_thread, java_lang_Thread::SLEEPING) {
565 if (is_alive()) {
566 _stat = java_thread->get_thread_stat();
567 _active = ThreadService::is_thread_monitoring_contention();
568 _stat->thread_sleep();
569 if (_active) {
570 _stat->thread_sleep_begin();
571 }
572 } else {
573 _active = false;
574 }
575 }
577 ~JavaThreadSleepState() {
578 if (_active) {
579 _stat->thread_sleep_end();
580 }
581 }
582 };
584 #endif // SHARE_VM_SERVICES_THREADSERVICE_HPP