1 /*
2 * Copyright (c) 2003, 2025, 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_SERVICES_THREADSERVICE_HPP
26 #define SHARE_SERVICES_THREADSERVICE_HPP
27
28 #include "classfile/classLoader.hpp"
29 #include "classfile/javaClasses.hpp"
30 #include "classfile/javaThreadStatus.hpp"
31 #include "runtime/handles.hpp"
32 #include "runtime/init.hpp"
33 #include "runtime/javaThread.hpp"
34 #include "runtime/objectMonitor.hpp"
35 #include "runtime/perfData.hpp"
36 #include "runtime/safepoint.hpp"
37 #include "runtime/threadSMR.hpp"
38 #include "services/management.hpp"
39
40 class DeadlockCycle;
41 class ObjectMonitorsView;
42 class OopClosure;
43 class StackFrameInfo;
44 class ThreadConcurrentLocks;
45 class ThreadDumpResult;
46 class ThreadSnapshot;
47 class ThreadStackTrace;
48
49 // VM monitoring and management support for the thread and
50 // synchronization subsystem
51 //
52 // Thread contention monitoring is disabled by default.
53 // When enabled, the VM will begin measuring the accumulated
54 // elapsed time a thread blocked on synchronization.
55 //
56 class ThreadService : public AllStatic {
57 private:
58 // These counters could be moved to Threads class
59 static PerfCounter* _total_threads_count;
60 static PerfVariable* _live_threads_count;
61 static PerfVariable* _peak_threads_count;
62 static PerfVariable* _daemon_threads_count;
63
64 // As could this...
65 // Number of heap bytes allocated by terminated threads.
66 static volatile jlong _exited_allocated_bytes;
67
68 // These 2 counters are like the above thread counts, but are
69 // atomically decremented in ThreadService::current_thread_exiting instead of
70 // ThreadService::remove_thread, so that the thread count is updated before
71 // Thread.join() returns.
72 static volatile int _atomic_threads_count;
73 static volatile int _atomic_daemon_threads_count;
74
75 static bool _thread_monitoring_contention_enabled;
76 static bool _thread_cpu_time_enabled;
77 static bool _thread_allocated_memory_enabled;
78
79 // Need to keep the list of thread dump result that
80 // keep references to Method* since thread dump can be
81 // requested by multiple threads concurrently.
82 static ThreadDumpResult* _threaddump_list;
83
84 static void decrement_thread_counts(JavaThread* jt, bool daemon);
85
86 // test if the JavaThread is a virtual thread or has a mounted virtual thread
87 static bool is_virtual_or_carrier_thread(JavaThread* jt);
88
89 public:
90 static void init();
91 static void add_thread(JavaThread* thread, bool daemon);
92 static void remove_thread(JavaThread* thread, bool daemon);
93 static void current_thread_exiting(JavaThread* jt, bool daemon);
94
95 static bool set_thread_monitoring_contention(bool flag);
96 static bool is_thread_monitoring_contention() { return _thread_monitoring_contention_enabled; }
97
98 static bool set_thread_cpu_time_enabled(bool flag);
99 static bool is_thread_cpu_time_enabled() { return _thread_cpu_time_enabled; }
100
101 static bool set_thread_allocated_memory_enabled(bool flag);
102 static bool is_thread_allocated_memory_enabled() { return _thread_allocated_memory_enabled; }
103
104 static jlong get_total_thread_count() { return _total_threads_count->get_value(); }
105 static jlong get_peak_thread_count() { return _peak_threads_count->get_value(); }
106 static int get_live_thread_count() { return _atomic_threads_count; }
107 static int get_daemon_thread_count() { return _atomic_daemon_threads_count; }
108
109 static jlong exited_allocated_bytes() { return Atomic::load(&_exited_allocated_bytes); }
110 static void incr_exited_allocated_bytes(jlong size) {
111 // No need for an atomic add because called under the Threads_lock,
112 // but because _exited_allocated_bytes is read concurrently, need
113 // atomic store to avoid readers seeing a partial update.
114 Atomic::store(&_exited_allocated_bytes, _exited_allocated_bytes + size);
115 }
116
117 // Support for thread dump
118 static void add_thread_dump(ThreadDumpResult* dump);
119 static void remove_thread_dump(ThreadDumpResult* dump);
120
121 static Handle get_current_contended_monitor(JavaThread* thread);
122
123 // This function is called by JVM_DumpThreads.
124 static Handle dump_stack_traces(GrowableArray<instanceHandle>* threads,
125 int num_threads, TRAPS);
126
127 static void reset_peak_thread_count();
128 static void reset_contention_count_stat(JavaThread* thread);
129 static void reset_contention_time_stat(JavaThread* thread);
130
131 static DeadlockCycle* find_deadlocks_at_safepoint(ThreadsList * t_list, bool object_monitors_only);
132
133 static void metadata_do(void f(Metadata*));
134 };
135
136 // Per-thread Statistics for synchronization
137 class ThreadStatistics : public CHeapObj<mtInternal> {
138 private:
139 // The following contention statistics are only updated by
140 // the thread owning these statistics when contention occurs.
141
142 jlong _contended_enter_count;
143 elapsedTimer _contended_enter_timer;
144 jlong _monitor_wait_count;
145 elapsedTimer _monitor_wait_timer;
146 jlong _sleep_count;
147 elapsedTimer _sleep_timer;
148
149
150 // These two reset flags are set to true when another thread
151 // requests to reset the statistics. The actual statistics
152 // are reset when the thread contention occurs and attempts
153 // to update the statistics.
154 bool _count_pending_reset;
155 bool _timer_pending_reset;
156
157 // Keep accurate times for potentially recursive class operations
158 int _perf_recursion_counts[PerfClassTraceTime::EVENT_TYPE_COUNT];
159 elapsedTimer _perf_timers[PerfClassTraceTime::EVENT_TYPE_COUNT];
160
161 // utility functions
162 void check_and_reset_count() {
163 if (!_count_pending_reset) return;
164 _contended_enter_count = 0;
165 _monitor_wait_count = 0;
166 _sleep_count = 0;
167 _count_pending_reset = 0;
168 }
169 void check_and_reset_timer() {
170 if (!_timer_pending_reset) return;
171 _contended_enter_timer.reset();
172 _monitor_wait_timer.reset();
173 _sleep_timer.reset();
174 _timer_pending_reset = 0;
175 }
176
177 public:
178 ThreadStatistics();
179
180 jlong contended_enter_count() { return (_count_pending_reset ? 0 : _contended_enter_count); }
181 jlong contended_enter_ticks() { return (_timer_pending_reset ? 0 : _contended_enter_timer.active_ticks()); }
182 jlong monitor_wait_count() { return (_count_pending_reset ? 0 : _monitor_wait_count); }
183 jlong monitor_wait_ticks() { return (_timer_pending_reset ? 0 : _monitor_wait_timer.active_ticks()); }
184 jlong sleep_count() { return (_count_pending_reset ? 0 : _sleep_count); }
185 jlong sleep_ticks() { return (_timer_pending_reset ? 0 : _sleep_timer.active_ticks()); }
186
187 void monitor_wait() { check_and_reset_count(); _monitor_wait_count++; }
188 void monitor_wait_begin() { check_and_reset_timer(); _monitor_wait_timer.start(); }
189 void monitor_wait_end() { _monitor_wait_timer.stop(); check_and_reset_timer(); }
190
191 void thread_sleep() { check_and_reset_count(); _sleep_count++; }
192 void thread_sleep_begin() { check_and_reset_timer(); _sleep_timer.start(); }
193 void thread_sleep_end() { _sleep_timer.stop(); check_and_reset_timer(); }
194
195 void contended_enter() { check_and_reset_count(); _contended_enter_count++; }
196 void contended_enter_begin() { check_and_reset_timer(); _contended_enter_timer.start(); }
197 void contended_enter_end() { _contended_enter_timer.stop(); check_and_reset_timer(); }
198
199 void reset_count_stat() { _count_pending_reset = true; }
200 void reset_time_stat() { _timer_pending_reset = true; }
201
202 int* perf_recursion_counts_addr() { return _perf_recursion_counts; }
203 elapsedTimer* perf_timers_addr() { return _perf_timers; }
204 };
205
206 // Thread snapshot to represent the thread state and statistics
207 class ThreadSnapshot : public CHeapObj<mtInternal> {
208 private:
209 // This JavaThread* is protected by being stored in objects that are
210 // protected by a ThreadsListSetter (ThreadDumpResult).
211 JavaThread* _thread;
212 OopHandle _threadObj;
213 JavaThreadStatus _thread_status;
214
215 bool _is_suspended;
216 bool _is_in_native;
217
218 jlong _contended_enter_ticks;
219 jlong _contended_enter_count;
220 jlong _monitor_wait_ticks;
221 jlong _monitor_wait_count;
222 jlong _sleep_ticks;
223 jlong _sleep_count;
224
225 OopHandle _blocker_object;
226 OopHandle _blocker_object_owner;
227
228 ThreadStackTrace* _stack_trace;
229 ThreadConcurrentLocks* _concurrent_locks;
230 ThreadSnapshot* _next;
231
232 // ThreadSnapshot instances should only be created via
233 // ThreadDumpResult::add_thread_snapshot.
234 friend class ThreadDumpResult;
235 ThreadSnapshot() : _thread(nullptr),
236 _stack_trace(nullptr), _concurrent_locks(nullptr), _next(nullptr) {};
237 void initialize(ThreadsList * t_list, JavaThread* thread);
238
239 public:
240 ~ThreadSnapshot();
241
242 JavaThreadStatus thread_status() { return _thread_status; }
243
244 oop threadObj() const;
245
246 void set_next(ThreadSnapshot* n) { _next = n; }
247
248 bool is_suspended() { return _is_suspended; }
249 bool is_in_native() { return _is_in_native; }
250
251 jlong contended_enter_count() { return _contended_enter_count; }
252 jlong contended_enter_ticks() { return _contended_enter_ticks; }
253 jlong monitor_wait_count() { return _monitor_wait_count; }
254 jlong monitor_wait_ticks() { return _monitor_wait_ticks; }
255 jlong sleep_count() { return _sleep_count; }
256 jlong sleep_ticks() { return _sleep_ticks; }
257
258
259 oop blocker_object() const;
260 oop blocker_object_owner() const;
261
262 ThreadSnapshot* next() const { return _next; }
263 ThreadStackTrace* get_stack_trace() { return _stack_trace; }
264 ThreadConcurrentLocks* get_concurrent_locks() { return _concurrent_locks; }
265
266 void dump_stack_at_safepoint(int max_depth, bool with_locked_monitors,
267 ObjectMonitorsView* monitors, bool full);
268 void set_concurrent_locks(ThreadConcurrentLocks* l) { _concurrent_locks = l; }
269 void metadata_do(void f(Metadata*));
270 };
271
272 class ThreadStackTrace : public CHeapObj<mtInternal> {
273 private:
274 JavaThread* _thread;
275 int _depth; // number of stack frames added
276 bool _with_locked_monitors;
277 GrowableArray<StackFrameInfo*>* _frames;
278 GrowableArray<OopHandle>* _jni_locked_monitors;
279
280 public:
281
282 ThreadStackTrace(JavaThread* thread, bool with_locked_monitors);
283 ~ThreadStackTrace();
284
285 JavaThread* thread() { return _thread; }
286 StackFrameInfo* stack_frame_at(int i) { return _frames->at(i); }
287 int get_stack_depth() { return _depth; }
288
289 void add_stack_frame(javaVFrame* jvf);
290 void dump_stack_at_safepoint(int max_depth, ObjectMonitorsView* monitors, bool full);
291 Handle allocate_fill_stack_trace_element_array(TRAPS);
292 void metadata_do(void f(Metadata*));
293 GrowableArray<OopHandle>* jni_locked_monitors() { return _jni_locked_monitors; }
294 int num_jni_locked_monitors() { return (_jni_locked_monitors != nullptr ? _jni_locked_monitors->length() : 0); }
295
296 bool is_owned_monitor_on_stack(oop object);
297 void add_jni_locked_monitor(oop object);
298 };
299
300 // StackFrameInfo for keeping Method* and bci during
301 // stack walking for later construction of StackTraceElement[]
302 // Java instances
303 class StackFrameInfo : public CHeapObj<mtInternal> {
304 private:
305 Method* _method;
306 int _bci;
307 GrowableArray<OopHandle>* _locked_monitors; // list of object monitors locked by this frame
308 // We need to save the mirrors in the backtrace to keep the class
309 // from being unloaded while we still have this stack trace.
310 OopHandle _class_holder;
311
312 public:
313
314 StackFrameInfo(javaVFrame* jvf, bool with_locked_monitors);
315 ~StackFrameInfo();
316 Method* method() const { return _method; }
317 int bci() const { return _bci; }
318 void metadata_do(void f(Metadata*));
319
320 int num_locked_monitors() { return (_locked_monitors != nullptr ? _locked_monitors->length() : 0); }
321 GrowableArray<OopHandle>* locked_monitors() { return _locked_monitors; }
322
323 void print_on(outputStream* st) const;
324 };
325
326 class ThreadConcurrentLocks : public CHeapObj<mtInternal> {
327 private:
328 GrowableArray<OopHandle>* _owned_locks;
329 ThreadConcurrentLocks* _next;
330 // This JavaThread* is protected in one of two different ways
331 // depending on the usage of the ThreadConcurrentLocks object:
332 // 1) by being stored in objects that are only allocated and used at a
333 // safepoint (ConcurrentLocksDump), or 2) by being stored in objects
334 // that are protected by a ThreadsListSetter (ThreadSnapshot inside
335 // ThreadDumpResult).
336 JavaThread* _thread;
337 public:
338 ThreadConcurrentLocks(JavaThread* thread);
339 ~ThreadConcurrentLocks();
340
341 void add_lock(instanceOop o);
342 void set_next(ThreadConcurrentLocks* n) { _next = n; }
343 ThreadConcurrentLocks* next() { return _next; }
344 JavaThread* java_thread() { return _thread; }
345 GrowableArray<OopHandle>* owned_locks() { return _owned_locks; }
346 };
347
348 class ConcurrentLocksDump : public StackObj {
349 private:
350 ThreadConcurrentLocks* _map;
351 ThreadConcurrentLocks* _last; // Last ThreadConcurrentLocks in the map
352 bool _retain_map_on_free;
353
354 void build_map(GrowableArray<oop>* aos_objects);
355 void add_lock(JavaThread* thread, instanceOop o);
356
357 public:
358 ConcurrentLocksDump(bool retain_map_on_free) : _map(nullptr), _last(nullptr), _retain_map_on_free(retain_map_on_free) {
359 assert(SafepointSynchronize::is_at_safepoint(), "Must be constructed at a safepoint.");
360 };
361 ConcurrentLocksDump() : _map(nullptr), _last(nullptr), _retain_map_on_free(false) {
362 assert(SafepointSynchronize::is_at_safepoint(), "Must be constructed at a safepoint.");
363 };
364 ~ConcurrentLocksDump();
365
366 void dump_at_safepoint();
367 ThreadConcurrentLocks* thread_concurrent_locks(JavaThread* thread);
368 void print_locks_on(JavaThread* t, outputStream* st);
369 };
370
371 class ThreadDumpResult : public StackObj {
372 private:
373 int _num_threads;
374 int _num_snapshots;
375 ThreadSnapshot* _snapshots;
376 ThreadSnapshot* _last;
377 ThreadDumpResult* _next;
378 ThreadsListSetter _setter; // Helper to set hazard ptr in the originating thread
379 // which protects the JavaThreads in _snapshots.
380
381 void link_thread_snapshot(ThreadSnapshot* ts);
382
383 public:
384 ThreadDumpResult();
385 ThreadDumpResult(int num_threads);
386 ~ThreadDumpResult();
387
388 ThreadSnapshot* add_thread_snapshot();
389 ThreadSnapshot* add_thread_snapshot(JavaThread* thread);
390
391 void set_next(ThreadDumpResult* next) { _next = next; }
392 ThreadDumpResult* next() { return _next; }
393 int num_threads() { return _num_threads; }
394 int num_snapshots() { return _num_snapshots; }
395 ThreadSnapshot* snapshots() { return _snapshots; }
396 void set_t_list() { _setter.set(); }
397 ThreadsList* t_list();
398 bool t_list_has_been_set() { return _setter.is_set(); }
399 void metadata_do(void f(Metadata*));
400 };
401
402 class DeadlockCycle : public CHeapObj<mtInternal> {
403 private:
404 GrowableArray<JavaThread*>* _threads;
405 DeadlockCycle* _next;
406 public:
407 DeadlockCycle();
408 ~DeadlockCycle();
409
410 DeadlockCycle* next() { return _next; }
411 void set_next(DeadlockCycle* d) { _next = d; }
412 void add_thread(JavaThread* t) { _threads->append(t); }
413 void reset() { _threads->clear(); }
414 int num_threads() { return _threads->length(); }
415 GrowableArray<JavaThread*>* threads() { return _threads; }
416 void print_on_with(ThreadsList * t_list, outputStream* st) const;
417 };
418
419 // Utility class to get list of java threads.
420 class ThreadsListEnumerator : public StackObj {
421 private:
422 GrowableArray<instanceHandle>* _threads_array;
423 public:
424 ThreadsListEnumerator(Thread* cur_thread,
425 bool include_jvmti_agent_threads = false,
426 bool include_jni_attaching_threads = true,
427 bool include_bound_virtual_threads = false);
428 int num_threads() { return _threads_array->length(); }
429 instanceHandle get_threadObj(int index) { return _threads_array->at(index); }
430 };
431
432
433 // abstract utility class to set new thread states, and restore previous after the block exits
434 class JavaThreadStatusChanger : public StackObj {
435 private:
436 JavaThreadStatus _old_state;
437 JavaThread* _java_thread;
438 bool _is_alive;
439
440 void save_old_state(JavaThread* java_thread) {
441 _java_thread = java_thread;
442 _is_alive = is_alive(java_thread);
443 if (is_alive()) {
444 _old_state = java_lang_Thread::get_thread_status(_java_thread->threadObj());
445 }
446 }
447
448 public:
449 static void set_thread_status(JavaThread* java_thread,
450 JavaThreadStatus state) {
451 java_lang_Thread::set_thread_status(java_thread->threadObj(), state);
452 }
453
454 void set_thread_status(JavaThreadStatus state) {
455 if (is_alive()) {
456 set_thread_status(_java_thread, state);
457 }
458 }
459
460 JavaThreadStatusChanger(JavaThread* java_thread,
461 JavaThreadStatus state) : _old_state(JavaThreadStatus::NEW) {
462 save_old_state(java_thread);
463 set_thread_status(state);
464 }
465
466 JavaThreadStatusChanger(JavaThread* java_thread) : _old_state(JavaThreadStatus::NEW) {
467 save_old_state(java_thread);
468 }
469
470 ~JavaThreadStatusChanger() {
471 set_thread_status(_old_state);
472 }
473
474 static bool is_alive(JavaThread* java_thread) {
475 return java_thread != nullptr && java_thread->threadObj() != nullptr;
476 }
477
478 bool is_alive() {
479 return _is_alive;
480 }
481 };
482
483 // Change status to waiting on an object (timed or indefinite)
484 class JavaThreadInObjectWaitState : public JavaThreadStatusChanger {
485 private:
486 ThreadStatistics* _stat;
487 bool _active;
488
489 public:
490 // Sets the java.lang.Thread state of the given JavaThread to reflect it is doing a regular,
491 // or timed, Object.wait call.
492 //
493 // The interruptible parameter, if false, indicates an internal uninterruptible wait,
494 // in which case we do not update the java.lang.Thread state. We do that by passing
495 // the current state to the JavaThreadStatusChanger so no actual change is observable,
496 // and skip the statistics updates. This avoids having to duplicate code paths for
497 // the interruptible and non-interruptible cases in the caller.
498 JavaThreadInObjectWaitState(JavaThread *java_thread, bool timed, bool interruptible) :
499 JavaThreadStatusChanger(java_thread,
500 interruptible ? (timed ? JavaThreadStatus::IN_OBJECT_WAIT_TIMED : JavaThreadStatus::IN_OBJECT_WAIT)
501 : java_lang_Thread::get_thread_status(java_thread->threadObj())) {
502 if (is_alive() && interruptible) { // in non-interruptible case we set _active = false below
503 _stat = java_thread->get_thread_stat();
504 _active = ThreadService::is_thread_monitoring_contention();
505 _stat->monitor_wait();
506 if (_active) {
507 _stat->monitor_wait_begin();
508 }
509 } else {
510 _active = false;
511 }
512 }
513
514 ~JavaThreadInObjectWaitState() {
515 if (_active) {
516 _stat->monitor_wait_end();
517 }
518 }
519 };
520
521 // Change status to parked (timed or indefinite)
522 class JavaThreadParkedState : public JavaThreadStatusChanger {
523 private:
524 ThreadStatistics* _stat;
525 bool _active;
526
527 public:
528 JavaThreadParkedState(JavaThread *java_thread, bool timed) :
529 JavaThreadStatusChanger(java_thread,
530 timed ? JavaThreadStatus::PARKED_TIMED : JavaThreadStatus::PARKED) {
531 if (is_alive()) {
532 _stat = java_thread->get_thread_stat();
533 _active = ThreadService::is_thread_monitoring_contention();
534 _stat->monitor_wait();
535 if (_active) {
536 _stat->monitor_wait_begin();
537 }
538 } else {
539 _active = false;
540 }
541 }
542
543 ~JavaThreadParkedState() {
544 if (_active) {
545 _stat->monitor_wait_end();
546 }
547 }
548 };
549
550 // Change status to blocked on (re-)entering a synchronization block
551 class JavaThreadBlockedOnMonitorEnterState : public JavaThreadStatusChanger {
552 private:
553 ThreadStatistics* _stat;
554 bool _active;
555
556 static bool contended_enter_begin(JavaThread *java_thread) {
557 set_thread_status(java_thread, JavaThreadStatus::BLOCKED_ON_MONITOR_ENTER);
558 ThreadStatistics* stat = java_thread->get_thread_stat();
559 stat->contended_enter();
560 bool active = ThreadService::is_thread_monitoring_contention();
561 if (active) {
562 stat->contended_enter_begin();
563 }
564 return active;
565 }
566
567 public:
568 // java_thread is waiting thread being blocked on monitor reenter.
569 // Current thread is the notifying thread which holds the monitor.
570 static bool wait_reenter_begin(JavaThread *java_thread, ObjectMonitor *obj_m) {
571 assert((java_thread != nullptr), "Java thread should not be null here");
572 bool active = false;
573 if (is_alive(java_thread)) {
574 active = contended_enter_begin(java_thread);
575 }
576 return active;
577 }
578
579 static void wait_reenter_end(JavaThread *java_thread, bool active) {
580 if (active) {
581 java_thread->get_thread_stat()->contended_enter_end();
582 }
583 set_thread_status(java_thread, JavaThreadStatus::RUNNABLE);
584 }
585
586 JavaThreadBlockedOnMonitorEnterState(JavaThread *java_thread, ObjectMonitor *obj_m) :
587 JavaThreadStatusChanger(java_thread), _stat(nullptr), _active(false) {
588 assert((java_thread != nullptr), "Java thread should not be null here");
589 // Change thread status and collect contended enter stats for monitor contended
590 // enter done for external java world objects and it is contended. All other cases
591 // like for vm internal objects and for external objects which are not contended
592 // thread status is not changed and contended enter stat is not collected.
593 _active = false;
594 if (is_alive() && obj_m->contentions() > 0) {
595 _stat = java_thread->get_thread_stat();
596 _active = contended_enter_begin(java_thread);
597 }
598 }
599
600 ~JavaThreadBlockedOnMonitorEnterState() {
601 if (_active) {
602 _stat->contended_enter_end();
603 }
604 }
605 };
606
607 // Change status to sleeping
608 class JavaThreadSleepState : public JavaThreadStatusChanger {
609 private:
610 ThreadStatistics* _stat;
611 bool _active;
612 public:
613 JavaThreadSleepState(JavaThread *java_thread) :
614 JavaThreadStatusChanger(java_thread, JavaThreadStatus::SLEEPING) {
615 if (is_alive()) {
616 _stat = java_thread->get_thread_stat();
617 _active = ThreadService::is_thread_monitoring_contention();
618 _stat->thread_sleep();
619 if (_active) {
620 _stat->thread_sleep_begin();
621 }
622 } else {
623 _active = false;
624 }
625 }
626
627 ~JavaThreadSleepState() {
628 if (_active) {
629 _stat->thread_sleep_end();
630 }
631 }
632 };
633
634
635 // jdk.internal.vm.ThreadSnapshot support
636 class ThreadSnapshotFactory: AllStatic {
637 public:
638 JVMTI_ONLY(static oop get_thread_snapshot(jobject jthread, TRAPS);)
639 };
640
641 #endif // SHARE_SERVICES_THREADSERVICE_HPP