Fri, 11 Feb 2011 14:15:16 +0100
7018257: jmm_DumpThreads allocates into permgen
Summary: Don't allocate in permgen
Reviewed-by: ysr, sla
1 /*
2 * Copyright (c) 2003, 2011, 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 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "memory/allocation.hpp"
28 #include "memory/heapInspection.hpp"
29 #include "memory/oopFactory.hpp"
30 #include "oops/instanceKlass.hpp"
31 #include "oops/oop.inline.hpp"
32 #include "runtime/handles.inline.hpp"
33 #include "runtime/init.hpp"
34 #include "runtime/thread.hpp"
35 #include "runtime/vframe.hpp"
36 #include "runtime/vmThread.hpp"
37 #include "runtime/vm_operations.hpp"
38 #include "services/threadService.hpp"
40 // TODO: we need to define a naming convention for perf counters
41 // to distinguish counters for:
42 // - standard JSR174 use
43 // - Hotspot extension (public and committed)
44 // - Hotspot extension (private/internal and uncommitted)
46 // Default is disabled.
47 bool ThreadService::_thread_monitoring_contention_enabled = false;
48 bool ThreadService::_thread_cpu_time_enabled = false;
49 bool ThreadService::_thread_allocated_memory_enabled = false;
51 PerfCounter* ThreadService::_total_threads_count = NULL;
52 PerfVariable* ThreadService::_live_threads_count = NULL;
53 PerfVariable* ThreadService::_peak_threads_count = NULL;
54 PerfVariable* ThreadService::_daemon_threads_count = NULL;
55 volatile int ThreadService::_exiting_threads_count = 0;
56 volatile int ThreadService::_exiting_daemon_threads_count = 0;
58 ThreadDumpResult* ThreadService::_threaddump_list = NULL;
60 static const int INITIAL_ARRAY_SIZE = 10;
62 void ThreadService::init() {
63 EXCEPTION_MARK;
65 // These counters are for java.lang.management API support.
66 // They are created even if -XX:-UsePerfData is set and in
67 // that case, they will be allocated on C heap.
69 _total_threads_count =
70 PerfDataManager::create_counter(JAVA_THREADS, "started",
71 PerfData::U_Events, CHECK);
73 _live_threads_count =
74 PerfDataManager::create_variable(JAVA_THREADS, "live",
75 PerfData::U_None, CHECK);
77 _peak_threads_count =
78 PerfDataManager::create_variable(JAVA_THREADS, "livePeak",
79 PerfData::U_None, CHECK);
81 _daemon_threads_count =
82 PerfDataManager::create_variable(JAVA_THREADS, "daemon",
83 PerfData::U_None, CHECK);
85 if (os::is_thread_cpu_time_supported()) {
86 _thread_cpu_time_enabled = true;
87 }
89 _thread_allocated_memory_enabled = true; // Always on, so enable it
90 }
92 void ThreadService::reset_peak_thread_count() {
93 // Acquire the lock to update the peak thread count
94 // to synchronize with thread addition and removal.
95 MutexLockerEx mu(Threads_lock);
96 _peak_threads_count->set_value(get_live_thread_count());
97 }
99 void ThreadService::add_thread(JavaThread* thread, bool daemon) {
100 // Do not count VM internal or JVMTI agent threads
101 if (thread->is_hidden_from_external_view() ||
102 thread->is_jvmti_agent_thread()) {
103 return;
104 }
106 _total_threads_count->inc();
107 _live_threads_count->inc();
109 if (_live_threads_count->get_value() > _peak_threads_count->get_value()) {
110 _peak_threads_count->set_value(_live_threads_count->get_value());
111 }
113 if (daemon) {
114 _daemon_threads_count->inc();
115 }
116 }
118 void ThreadService::remove_thread(JavaThread* thread, bool daemon) {
119 Atomic::dec((jint*) &_exiting_threads_count);
121 if (thread->is_hidden_from_external_view() ||
122 thread->is_jvmti_agent_thread()) {
123 return;
124 }
126 _live_threads_count->set_value(_live_threads_count->get_value() - 1);
128 if (daemon) {
129 _daemon_threads_count->set_value(_daemon_threads_count->get_value() - 1);
130 Atomic::dec((jint*) &_exiting_daemon_threads_count);
131 }
132 }
134 void ThreadService::current_thread_exiting(JavaThread* jt) {
135 assert(jt == JavaThread::current(), "Called by current thread");
136 Atomic::inc((jint*) &_exiting_threads_count);
138 oop threadObj = jt->threadObj();
139 if (threadObj != NULL && java_lang_Thread::is_daemon(threadObj)) {
140 Atomic::inc((jint*) &_exiting_daemon_threads_count);
141 }
142 }
144 // FIXME: JVMTI should call this function
145 Handle ThreadService::get_current_contended_monitor(JavaThread* thread) {
146 assert(thread != NULL, "should be non-NULL");
147 assert(Threads_lock->owned_by_self(), "must grab Threads_lock or be at safepoint");
149 ObjectMonitor *wait_obj = thread->current_waiting_monitor();
151 oop obj = NULL;
152 if (wait_obj != NULL) {
153 // thread is doing an Object.wait() call
154 obj = (oop) wait_obj->object();
155 assert(obj != NULL, "Object.wait() should have an object");
156 } else {
157 ObjectMonitor *enter_obj = thread->current_pending_monitor();
158 if (enter_obj != NULL) {
159 // thread is trying to enter() or raw_enter() an ObjectMonitor.
160 obj = (oop) enter_obj->object();
161 }
162 // If obj == NULL, then ObjectMonitor is raw which doesn't count.
163 }
165 Handle h(obj);
166 return h;
167 }
169 bool ThreadService::set_thread_monitoring_contention(bool flag) {
170 MutexLocker m(Management_lock);
172 bool prev = _thread_monitoring_contention_enabled;
173 _thread_monitoring_contention_enabled = flag;
175 return prev;
176 }
178 bool ThreadService::set_thread_cpu_time_enabled(bool flag) {
179 MutexLocker m(Management_lock);
181 bool prev = _thread_cpu_time_enabled;
182 _thread_cpu_time_enabled = flag;
184 return prev;
185 }
187 bool ThreadService::set_thread_allocated_memory_enabled(bool flag) {
188 MutexLocker m(Management_lock);
190 bool prev = _thread_allocated_memory_enabled;
191 _thread_allocated_memory_enabled = flag;
193 return prev;
194 }
196 // GC support
197 void ThreadService::oops_do(OopClosure* f) {
198 for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) {
199 dump->oops_do(f);
200 }
201 }
203 void ThreadService::add_thread_dump(ThreadDumpResult* dump) {
204 MutexLocker ml(Management_lock);
205 if (_threaddump_list == NULL) {
206 _threaddump_list = dump;
207 } else {
208 dump->set_next(_threaddump_list);
209 _threaddump_list = dump;
210 }
211 }
213 void ThreadService::remove_thread_dump(ThreadDumpResult* dump) {
214 MutexLocker ml(Management_lock);
216 ThreadDumpResult* prev = NULL;
217 bool found = false;
218 for (ThreadDumpResult* d = _threaddump_list; d != NULL; prev = d, d = d->next()) {
219 if (d == dump) {
220 if (prev == NULL) {
221 _threaddump_list = dump->next();
222 } else {
223 prev->set_next(dump->next());
224 }
225 found = true;
226 break;
227 }
228 }
229 assert(found, "The threaddump result to be removed must exist.");
230 }
232 // Dump stack trace of threads specified in the given threads array.
233 // Returns StackTraceElement[][] each element is the stack trace of a thread in
234 // the corresponding entry in the given threads array
235 Handle ThreadService::dump_stack_traces(GrowableArray<instanceHandle>* threads,
236 int num_threads,
237 TRAPS) {
238 assert(num_threads > 0, "just checking");
240 ThreadDumpResult dump_result;
241 VM_ThreadDump op(&dump_result,
242 threads,
243 num_threads,
244 -1, /* entire stack */
245 false, /* with locked monitors */
246 false /* with locked synchronizers */);
247 VMThread::execute(&op);
249 // Allocate the resulting StackTraceElement[][] object
251 ResourceMark rm(THREAD);
252 klassOop k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_StackTraceElement_array(), true, CHECK_NH);
253 objArrayKlassHandle ik (THREAD, k);
254 objArrayOop r = oopFactory::new_objArray(ik(), num_threads, CHECK_NH);
255 objArrayHandle result_obj(THREAD, r);
257 int num_snapshots = dump_result.num_snapshots();
258 assert(num_snapshots == num_threads, "Must have num_threads thread snapshots");
259 int i = 0;
260 for (ThreadSnapshot* ts = dump_result.snapshots(); ts != NULL; i++, ts = ts->next()) {
261 ThreadStackTrace* stacktrace = ts->get_stack_trace();
262 if (stacktrace == NULL) {
263 // No stack trace
264 result_obj->obj_at_put(i, NULL);
265 } else {
266 // Construct an array of java/lang/StackTraceElement object
267 Handle backtrace_h = stacktrace->allocate_fill_stack_trace_element_array(CHECK_NH);
268 result_obj->obj_at_put(i, backtrace_h());
269 }
270 }
272 return result_obj;
273 }
275 void ThreadService::reset_contention_count_stat(JavaThread* thread) {
276 ThreadStatistics* stat = thread->get_thread_stat();
277 if (stat != NULL) {
278 stat->reset_count_stat();
279 }
280 }
282 void ThreadService::reset_contention_time_stat(JavaThread* thread) {
283 ThreadStatistics* stat = thread->get_thread_stat();
284 if (stat != NULL) {
285 stat->reset_time_stat();
286 }
287 }
289 // Find deadlocks involving object monitors and concurrent locks if concurrent_locks is true
290 DeadlockCycle* ThreadService::find_deadlocks_at_safepoint(bool concurrent_locks) {
291 // This code was modified from the original Threads::find_deadlocks code.
292 int globalDfn = 0, thisDfn;
293 ObjectMonitor* waitingToLockMonitor = NULL;
294 oop waitingToLockBlocker = NULL;
295 bool blocked_on_monitor = false;
296 JavaThread *currentThread, *previousThread;
297 int num_deadlocks = 0;
299 for (JavaThread* p = Threads::first(); p != NULL; p = p->next()) {
300 // Initialize the depth-first-number
301 p->set_depth_first_number(-1);
302 }
304 DeadlockCycle* deadlocks = NULL;
305 DeadlockCycle* last = NULL;
306 DeadlockCycle* cycle = new DeadlockCycle();
307 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
308 if (jt->depth_first_number() >= 0) {
309 // this thread was already visited
310 continue;
311 }
313 thisDfn = globalDfn;
314 jt->set_depth_first_number(globalDfn++);
315 previousThread = jt;
316 currentThread = jt;
318 cycle->reset();
320 // When there is a deadlock, all the monitors involved in the dependency
321 // cycle must be contended and heavyweight. So we only care about the
322 // heavyweight monitor a thread is waiting to lock.
323 waitingToLockMonitor = (ObjectMonitor*)jt->current_pending_monitor();
324 if (concurrent_locks) {
325 waitingToLockBlocker = jt->current_park_blocker();
326 }
327 while (waitingToLockMonitor != NULL || waitingToLockBlocker != NULL) {
328 cycle->add_thread(currentThread);
329 if (waitingToLockMonitor != NULL) {
330 currentThread = Threads::owning_thread_from_monitor_owner((address)waitingToLockMonitor->owner(),
331 false /* no locking needed */);
332 } else {
333 if (concurrent_locks) {
334 if (waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) {
335 oop threadObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
336 currentThread = threadObj != NULL ? java_lang_Thread::thread(threadObj) : NULL;
337 } else {
338 currentThread = NULL;
339 }
340 }
341 }
343 if (currentThread == NULL) {
344 // No dependency on another thread
345 break;
346 }
347 if (currentThread->depth_first_number() < 0) {
348 // First visit to this thread
349 currentThread->set_depth_first_number(globalDfn++);
350 } else if (currentThread->depth_first_number() < thisDfn) {
351 // Thread already visited, and not on a (new) cycle
352 break;
353 } else if (currentThread == previousThread) {
354 // Self-loop, ignore
355 break;
356 } else {
357 // We have a (new) cycle
358 num_deadlocks++;
360 cycle->set_deadlock(true);
362 // add this cycle to the deadlocks list
363 if (deadlocks == NULL) {
364 deadlocks = cycle;
365 } else {
366 last->set_next(cycle);
367 }
368 last = cycle;
369 cycle = new DeadlockCycle();
370 break;
371 }
372 previousThread = currentThread;
373 waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
374 if (concurrent_locks) {
375 waitingToLockBlocker = currentThread->current_park_blocker();
376 }
377 }
379 }
381 return deadlocks;
382 }
384 ThreadDumpResult::ThreadDumpResult() : _num_threads(0), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) {
386 // Create a new ThreadDumpResult object and append to the list.
387 // If GC happens before this function returns, methodOop
388 // in the stack trace will be visited.
389 ThreadService::add_thread_dump(this);
390 }
392 ThreadDumpResult::ThreadDumpResult(int num_threads) : _num_threads(num_threads), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) {
393 // Create a new ThreadDumpResult object and append to the list.
394 // If GC happens before this function returns, oops
395 // will be visited.
396 ThreadService::add_thread_dump(this);
397 }
399 ThreadDumpResult::~ThreadDumpResult() {
400 ThreadService::remove_thread_dump(this);
402 // free all the ThreadSnapshot objects created during
403 // the VM_ThreadDump operation
404 ThreadSnapshot* ts = _snapshots;
405 while (ts != NULL) {
406 ThreadSnapshot* p = ts;
407 ts = ts->next();
408 delete p;
409 }
410 }
413 void ThreadDumpResult::add_thread_snapshot(ThreadSnapshot* ts) {
414 assert(_num_threads == 0 || _num_snapshots < _num_threads,
415 "_num_snapshots must be less than _num_threads");
416 _num_snapshots++;
417 if (_snapshots == NULL) {
418 _snapshots = ts;
419 } else {
420 _last->set_next(ts);
421 }
422 _last = ts;
423 }
425 void ThreadDumpResult::oops_do(OopClosure* f) {
426 for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) {
427 ts->oops_do(f);
428 }
429 }
431 StackFrameInfo::StackFrameInfo(javaVFrame* jvf, bool with_lock_info) {
432 _method = jvf->method();
433 _bci = jvf->bci();
434 _locked_monitors = NULL;
435 if (with_lock_info) {
436 ResourceMark rm;
437 GrowableArray<MonitorInfo*>* list = jvf->locked_monitors();
438 int length = list->length();
439 if (length > 0) {
440 _locked_monitors = new (ResourceObj::C_HEAP) GrowableArray<oop>(length, true);
441 for (int i = 0; i < length; i++) {
442 MonitorInfo* monitor = list->at(i);
443 assert(monitor->owner(), "This monitor must have an owning object");
444 _locked_monitors->append(monitor->owner());
445 }
446 }
447 }
448 }
450 void StackFrameInfo::oops_do(OopClosure* f) {
451 f->do_oop((oop*) &_method);
452 if (_locked_monitors != NULL) {
453 int length = _locked_monitors->length();
454 for (int i = 0; i < length; i++) {
455 f->do_oop((oop*) _locked_monitors->adr_at(i));
456 }
457 }
458 }
460 void StackFrameInfo::print_on(outputStream* st) const {
461 ResourceMark rm;
462 java_lang_Throwable::print_stack_element(st, method(), bci());
463 int len = (_locked_monitors != NULL ? _locked_monitors->length() : 0);
464 for (int i = 0; i < len; i++) {
465 oop o = _locked_monitors->at(i);
466 instanceKlass* ik = instanceKlass::cast(o->klass());
467 st->print_cr("\t- locked <" INTPTR_FORMAT "> (a %s)", (address)o, ik->external_name());
468 }
470 }
472 // Iterate through monitor cache to find JNI locked monitors
473 class InflatedMonitorsClosure: public MonitorClosure {
474 private:
475 ThreadStackTrace* _stack_trace;
476 Thread* _thread;
477 public:
478 InflatedMonitorsClosure(Thread* t, ThreadStackTrace* st) {
479 _thread = t;
480 _stack_trace = st;
481 }
482 void do_monitor(ObjectMonitor* mid) {
483 if (mid->owner() == _thread) {
484 oop object = (oop) mid->object();
485 if (!_stack_trace->is_owned_monitor_on_stack(object)) {
486 _stack_trace->add_jni_locked_monitor(object);
487 }
488 }
489 }
490 };
492 ThreadStackTrace::ThreadStackTrace(JavaThread* t, bool with_locked_monitors) {
493 _thread = t;
494 _frames = new (ResourceObj::C_HEAP) GrowableArray<StackFrameInfo*>(INITIAL_ARRAY_SIZE, true);
495 _depth = 0;
496 _with_locked_monitors = with_locked_monitors;
497 if (_with_locked_monitors) {
498 _jni_locked_monitors = new (ResourceObj::C_HEAP) GrowableArray<oop>(INITIAL_ARRAY_SIZE, true);
499 } else {
500 _jni_locked_monitors = NULL;
501 }
502 }
504 ThreadStackTrace::~ThreadStackTrace() {
505 for (int i = 0; i < _frames->length(); i++) {
506 delete _frames->at(i);
507 }
508 delete _frames;
509 if (_jni_locked_monitors != NULL) {
510 delete _jni_locked_monitors;
511 }
512 }
514 void ThreadStackTrace::dump_stack_at_safepoint(int maxDepth) {
515 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
517 if (_thread->has_last_Java_frame()) {
518 RegisterMap reg_map(_thread);
519 vframe* start_vf = _thread->last_java_vframe(®_map);
520 int count = 0;
521 for (vframe* f = start_vf; f; f = f->sender() ) {
522 if (f->is_java_frame()) {
523 javaVFrame* jvf = javaVFrame::cast(f);
524 add_stack_frame(jvf);
525 count++;
526 } else {
527 // Ignore non-Java frames
528 }
529 if (maxDepth > 0 && count == maxDepth) {
530 // Skip frames if more than maxDepth
531 break;
532 }
533 }
534 }
536 if (_with_locked_monitors) {
537 // Iterate inflated monitors and find monitors locked by this thread
538 // not found in the stack
539 InflatedMonitorsClosure imc(_thread, this);
540 ObjectSynchronizer::monitors_iterate(&imc);
541 }
542 }
545 bool ThreadStackTrace::is_owned_monitor_on_stack(oop object) {
546 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
548 bool found = false;
549 int num_frames = get_stack_depth();
550 for (int depth = 0; depth < num_frames; depth++) {
551 StackFrameInfo* frame = stack_frame_at(depth);
552 int len = frame->num_locked_monitors();
553 GrowableArray<oop>* locked_monitors = frame->locked_monitors();
554 for (int j = 0; j < len; j++) {
555 oop monitor = locked_monitors->at(j);
556 assert(monitor != NULL && monitor->is_instance(), "must be a Java object");
557 if (monitor == object) {
558 found = true;
559 break;
560 }
561 }
562 }
563 return found;
564 }
566 Handle ThreadStackTrace::allocate_fill_stack_trace_element_array(TRAPS) {
567 klassOop k = SystemDictionary::StackTraceElement_klass();
568 assert(k != NULL, "must be loaded in 1.4+");
569 instanceKlassHandle ik(THREAD, k);
571 // Allocate an array of java/lang/StackTraceElement object
572 objArrayOop ste = oopFactory::new_objArray(ik(), _depth, CHECK_NH);
573 objArrayHandle backtrace(THREAD, ste);
574 for (int j = 0; j < _depth; j++) {
575 StackFrameInfo* frame = _frames->at(j);
576 methodHandle mh(THREAD, frame->method());
577 oop element = java_lang_StackTraceElement::create(mh, frame->bci(), CHECK_NH);
578 backtrace->obj_at_put(j, element);
579 }
580 return backtrace;
581 }
583 void ThreadStackTrace::add_stack_frame(javaVFrame* jvf) {
584 StackFrameInfo* frame = new StackFrameInfo(jvf, _with_locked_monitors);
585 _frames->append(frame);
586 _depth++;
587 }
589 void ThreadStackTrace::oops_do(OopClosure* f) {
590 int length = _frames->length();
591 for (int i = 0; i < length; i++) {
592 _frames->at(i)->oops_do(f);
593 }
595 length = (_jni_locked_monitors != NULL ? _jni_locked_monitors->length() : 0);
596 for (int j = 0; j < length; j++) {
597 f->do_oop((oop*) _jni_locked_monitors->adr_at(j));
598 }
599 }
601 ConcurrentLocksDump::~ConcurrentLocksDump() {
602 if (_retain_map_on_free) {
603 return;
604 }
606 for (ThreadConcurrentLocks* t = _map; t != NULL;) {
607 ThreadConcurrentLocks* tcl = t;
608 t = t->next();
609 delete tcl;
610 }
611 }
613 void ConcurrentLocksDump::dump_at_safepoint() {
614 // dump all locked concurrent locks
615 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
617 if (JDK_Version::is_gte_jdk16x_version()) {
618 ResourceMark rm;
620 GrowableArray<oop>* aos_objects = new GrowableArray<oop>(INITIAL_ARRAY_SIZE);
622 // Find all instances of AbstractOwnableSynchronizer
623 HeapInspection::find_instances_at_safepoint(SystemDictionary::abstract_ownable_synchronizer_klass(),
624 aos_objects);
625 // Build a map of thread to its owned AQS locks
626 build_map(aos_objects);
627 }
628 }
631 // build a map of JavaThread to all its owned AbstractOwnableSynchronizer
632 void ConcurrentLocksDump::build_map(GrowableArray<oop>* aos_objects) {
633 int length = aos_objects->length();
634 for (int i = 0; i < length; i++) {
635 oop o = aos_objects->at(i);
636 oop owner_thread_obj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(o);
637 if (owner_thread_obj != NULL) {
638 JavaThread* thread = java_lang_Thread::thread(owner_thread_obj);
639 assert(o->is_instance(), "Must be an instanceOop");
640 add_lock(thread, (instanceOop) o);
641 }
642 }
643 }
645 void ConcurrentLocksDump::add_lock(JavaThread* thread, instanceOop o) {
646 ThreadConcurrentLocks* tcl = thread_concurrent_locks(thread);
647 if (tcl != NULL) {
648 tcl->add_lock(o);
649 return;
650 }
652 // First owned lock found for this thread
653 tcl = new ThreadConcurrentLocks(thread);
654 tcl->add_lock(o);
655 if (_map == NULL) {
656 _map = tcl;
657 } else {
658 _last->set_next(tcl);
659 }
660 _last = tcl;
661 }
663 ThreadConcurrentLocks* ConcurrentLocksDump::thread_concurrent_locks(JavaThread* thread) {
664 for (ThreadConcurrentLocks* tcl = _map; tcl != NULL; tcl = tcl->next()) {
665 if (tcl->java_thread() == thread) {
666 return tcl;
667 }
668 }
669 return NULL;
670 }
672 void ConcurrentLocksDump::print_locks_on(JavaThread* t, outputStream* st) {
673 st->print_cr(" Locked ownable synchronizers:");
674 ThreadConcurrentLocks* tcl = thread_concurrent_locks(t);
675 GrowableArray<instanceOop>* locks = (tcl != NULL ? tcl->owned_locks() : NULL);
676 if (locks == NULL || locks->is_empty()) {
677 st->print_cr("\t- None");
678 st->cr();
679 return;
680 }
682 for (int i = 0; i < locks->length(); i++) {
683 instanceOop obj = locks->at(i);
684 instanceKlass* ik = instanceKlass::cast(obj->klass());
685 st->print_cr("\t- <" INTPTR_FORMAT "> (a %s)", (address)obj, ik->external_name());
686 }
687 st->cr();
688 }
690 ThreadConcurrentLocks::ThreadConcurrentLocks(JavaThread* thread) {
691 _thread = thread;
692 _owned_locks = new (ResourceObj::C_HEAP) GrowableArray<instanceOop>(INITIAL_ARRAY_SIZE, true);
693 _next = NULL;
694 }
696 ThreadConcurrentLocks::~ThreadConcurrentLocks() {
697 delete _owned_locks;
698 }
700 void ThreadConcurrentLocks::add_lock(instanceOop o) {
701 _owned_locks->append(o);
702 }
704 void ThreadConcurrentLocks::oops_do(OopClosure* f) {
705 int length = _owned_locks->length();
706 for (int i = 0; i < length; i++) {
707 f->do_oop((oop*) _owned_locks->adr_at(i));
708 }
709 }
711 ThreadStatistics::ThreadStatistics() {
712 _contended_enter_count = 0;
713 _monitor_wait_count = 0;
714 _sleep_count = 0;
715 _count_pending_reset = false;
716 _timer_pending_reset = false;
717 memset((void*) _perf_recursion_counts, 0, sizeof(_perf_recursion_counts));
718 }
720 ThreadSnapshot::ThreadSnapshot(JavaThread* thread) {
721 _thread = thread;
722 _threadObj = thread->threadObj();
723 _stack_trace = NULL;
724 _concurrent_locks = NULL;
725 _next = NULL;
727 ThreadStatistics* stat = thread->get_thread_stat();
728 _contended_enter_ticks = stat->contended_enter_ticks();
729 _contended_enter_count = stat->contended_enter_count();
730 _monitor_wait_ticks = stat->monitor_wait_ticks();
731 _monitor_wait_count = stat->monitor_wait_count();
732 _sleep_ticks = stat->sleep_ticks();
733 _sleep_count = stat->sleep_count();
735 _blocker_object = NULL;
736 _blocker_object_owner = NULL;
738 _thread_status = java_lang_Thread::get_thread_status(_threadObj);
739 _is_ext_suspended = thread->is_being_ext_suspended();
740 _is_in_native = (thread->thread_state() == _thread_in_native);
742 if (_thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER ||
743 _thread_status == java_lang_Thread::IN_OBJECT_WAIT ||
744 _thread_status == java_lang_Thread::IN_OBJECT_WAIT_TIMED) {
746 Handle obj = ThreadService::get_current_contended_monitor(thread);
747 if (obj() == NULL) {
748 // monitor no longer exists; thread is not blocked
749 _thread_status = java_lang_Thread::RUNNABLE;
750 } else {
751 _blocker_object = obj();
752 JavaThread* owner = ObjectSynchronizer::get_lock_owner(obj, false);
753 if ((owner == NULL && _thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER)
754 || (owner != NULL && owner->is_attaching())) {
755 // ownership information of the monitor is not available
756 // (may no longer be owned or releasing to some other thread)
757 // make this thread in RUNNABLE state.
758 // And when the owner thread is in attaching state, the java thread
759 // is not completely initialized. For example thread name and id
760 // and may not be set, so hide the attaching thread.
761 _thread_status = java_lang_Thread::RUNNABLE;
762 _blocker_object = NULL;
763 } else if (owner != NULL) {
764 _blocker_object_owner = owner->threadObj();
765 }
766 }
767 }
769 // Support for JSR-166 locks
770 if (JDK_Version::current().supports_thread_park_blocker() &&
771 (_thread_status == java_lang_Thread::PARKED ||
772 _thread_status == java_lang_Thread::PARKED_TIMED)) {
774 _blocker_object = thread->current_park_blocker();
775 if (_blocker_object != NULL && _blocker_object->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) {
776 _blocker_object_owner = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(_blocker_object);
777 }
778 }
779 }
781 ThreadSnapshot::~ThreadSnapshot() {
782 delete _stack_trace;
783 delete _concurrent_locks;
784 }
786 void ThreadSnapshot::dump_stack_at_safepoint(int max_depth, bool with_locked_monitors) {
787 _stack_trace = new ThreadStackTrace(_thread, with_locked_monitors);
788 _stack_trace->dump_stack_at_safepoint(max_depth);
789 }
792 void ThreadSnapshot::oops_do(OopClosure* f) {
793 f->do_oop(&_threadObj);
794 f->do_oop(&_blocker_object);
795 f->do_oop(&_blocker_object_owner);
796 if (_stack_trace != NULL) {
797 _stack_trace->oops_do(f);
798 }
799 if (_concurrent_locks != NULL) {
800 _concurrent_locks->oops_do(f);
801 }
802 }
804 DeadlockCycle::DeadlockCycle() {
805 _is_deadlock = false;
806 _threads = new (ResourceObj::C_HEAP) GrowableArray<JavaThread*>(INITIAL_ARRAY_SIZE, true);
807 _next = NULL;
808 }
810 DeadlockCycle::~DeadlockCycle() {
811 delete _threads;
812 }
814 void DeadlockCycle::print_on(outputStream* st) const {
815 st->cr();
816 st->print_cr("Found one Java-level deadlock:");
817 st->print("=============================");
819 JavaThread* currentThread;
820 ObjectMonitor* waitingToLockMonitor;
821 oop waitingToLockBlocker;
822 int len = _threads->length();
823 for (int i = 0; i < len; i++) {
824 currentThread = _threads->at(i);
825 waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
826 waitingToLockBlocker = currentThread->current_park_blocker();
827 st->cr();
828 st->print_cr("\"%s\":", currentThread->get_thread_name());
829 const char* owner_desc = ",\n which is held by";
830 if (waitingToLockMonitor != NULL) {
831 st->print(" waiting to lock monitor " INTPTR_FORMAT, waitingToLockMonitor);
832 oop obj = (oop)waitingToLockMonitor->object();
833 if (obj != NULL) {
834 st->print(" (object "INTPTR_FORMAT ", a %s)", (address)obj,
835 (instanceKlass::cast(obj->klass()))->external_name());
837 if (!currentThread->current_pending_monitor_is_from_java()) {
838 owner_desc = "\n in JNI, which is held by";
839 }
840 } else {
841 // No Java object associated - a JVMTI raw monitor
842 owner_desc = " (JVMTI raw monitor),\n which is held by";
843 }
844 currentThread = Threads::owning_thread_from_monitor_owner(
845 (address)waitingToLockMonitor->owner(), false /* no locking needed */);
846 } else {
847 st->print(" waiting for ownable synchronizer " INTPTR_FORMAT ", (a %s)",
848 (address)waitingToLockBlocker,
849 (instanceKlass::cast(waitingToLockBlocker->klass()))->external_name());
850 assert(waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass()),
851 "Must be an AbstractOwnableSynchronizer");
852 oop ownerObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
853 currentThread = java_lang_Thread::thread(ownerObj);
854 }
855 st->print("%s \"%s\"", owner_desc, currentThread->get_thread_name());
856 }
858 st->cr();
859 st->cr();
861 // Print stack traces
862 bool oldJavaMonitorsInStackTrace = JavaMonitorsInStackTrace;
863 JavaMonitorsInStackTrace = true;
864 st->print_cr("Java stack information for the threads listed above:");
865 st->print_cr("===================================================");
866 for (int j = 0; j < len; j++) {
867 currentThread = _threads->at(j);
868 st->print_cr("\"%s\":", currentThread->get_thread_name());
869 currentThread->print_stack_on(st);
870 }
871 JavaMonitorsInStackTrace = oldJavaMonitorsInStackTrace;
872 }
874 ThreadsListEnumerator::ThreadsListEnumerator(Thread* cur_thread,
875 bool include_jvmti_agent_threads,
876 bool include_jni_attaching_threads) {
877 assert(cur_thread == Thread::current(), "Check current thread");
879 int init_size = ThreadService::get_live_thread_count();
880 _threads_array = new GrowableArray<instanceHandle>(init_size);
882 MutexLockerEx ml(Threads_lock);
884 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
885 // skips JavaThreads in the process of exiting
886 // and also skips VM internal JavaThreads
887 // Threads in _thread_new or _thread_new_trans state are included.
888 // i.e. threads have been started but not yet running.
889 if (jt->threadObj() == NULL ||
890 jt->is_exiting() ||
891 !java_lang_Thread::is_alive(jt->threadObj()) ||
892 jt->is_hidden_from_external_view()) {
893 continue;
894 }
896 // skip agent threads
897 if (!include_jvmti_agent_threads && jt->is_jvmti_agent_thread()) {
898 continue;
899 }
901 // skip jni threads in the process of attaching
902 if (!include_jni_attaching_threads && jt->is_attaching()) {
903 continue;
904 }
906 instanceHandle h(cur_thread, (instanceOop) jt->threadObj());
907 _threads_array->append(h);
908 }
909 }