Thu, 22 May 2014 15:52:41 -0400
8037816: Fix for 8036122 breaks build with Xcode5/clang
8043029: Change 8037816 breaks HS build with older GCC versions which don't support diagnostic pragmas
8043164: Format warning in traceStream.hpp
Summary: Backport of main fix + two corrections, enables clang compilation, turns on format attributes, corrects/mutes warnings
Reviewed-by: kvn, coleenp, iveresov, twisti
1 /*
2 * Copyright (c) 2003, 2014, 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 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
42 // TODO: we need to define a naming convention for perf counters
43 // to distinguish counters for:
44 // - standard JSR174 use
45 // - Hotspot extension (public and committed)
46 // - Hotspot extension (private/internal and uncommitted)
48 // Default is disabled.
49 bool ThreadService::_thread_monitoring_contention_enabled = false;
50 bool ThreadService::_thread_cpu_time_enabled = false;
51 bool ThreadService::_thread_allocated_memory_enabled = false;
53 PerfCounter* ThreadService::_total_threads_count = NULL;
54 PerfVariable* ThreadService::_live_threads_count = NULL;
55 PerfVariable* ThreadService::_peak_threads_count = NULL;
56 PerfVariable* ThreadService::_daemon_threads_count = NULL;
57 volatile int ThreadService::_exiting_threads_count = 0;
58 volatile int ThreadService::_exiting_daemon_threads_count = 0;
60 ThreadDumpResult* ThreadService::_threaddump_list = NULL;
62 static const int INITIAL_ARRAY_SIZE = 10;
64 void ThreadService::init() {
65 EXCEPTION_MARK;
67 // These counters are for java.lang.management API support.
68 // They are created even if -XX:-UsePerfData is set and in
69 // that case, they will be allocated on C heap.
71 _total_threads_count =
72 PerfDataManager::create_counter(JAVA_THREADS, "started",
73 PerfData::U_Events, CHECK);
75 _live_threads_count =
76 PerfDataManager::create_variable(JAVA_THREADS, "live",
77 PerfData::U_None, CHECK);
79 _peak_threads_count =
80 PerfDataManager::create_variable(JAVA_THREADS, "livePeak",
81 PerfData::U_None, CHECK);
83 _daemon_threads_count =
84 PerfDataManager::create_variable(JAVA_THREADS, "daemon",
85 PerfData::U_None, CHECK);
87 if (os::is_thread_cpu_time_supported()) {
88 _thread_cpu_time_enabled = true;
89 }
91 _thread_allocated_memory_enabled = true; // Always on, so enable it
92 }
94 void ThreadService::reset_peak_thread_count() {
95 // Acquire the lock to update the peak thread count
96 // to synchronize with thread addition and removal.
97 MutexLockerEx mu(Threads_lock);
98 _peak_threads_count->set_value(get_live_thread_count());
99 }
101 void ThreadService::add_thread(JavaThread* thread, bool daemon) {
102 // Do not count VM internal or JVMTI agent threads
103 if (thread->is_hidden_from_external_view() ||
104 thread->is_jvmti_agent_thread()) {
105 return;
106 }
108 _total_threads_count->inc();
109 _live_threads_count->inc();
111 if (_live_threads_count->get_value() > _peak_threads_count->get_value()) {
112 _peak_threads_count->set_value(_live_threads_count->get_value());
113 }
115 if (daemon) {
116 _daemon_threads_count->inc();
117 }
118 }
120 void ThreadService::remove_thread(JavaThread* thread, bool daemon) {
121 Atomic::dec((jint*) &_exiting_threads_count);
123 if (thread->is_hidden_from_external_view() ||
124 thread->is_jvmti_agent_thread()) {
125 return;
126 }
128 _live_threads_count->set_value(_live_threads_count->get_value() - 1);
130 if (daemon) {
131 _daemon_threads_count->set_value(_daemon_threads_count->get_value() - 1);
132 Atomic::dec((jint*) &_exiting_daemon_threads_count);
133 }
134 }
136 void ThreadService::current_thread_exiting(JavaThread* jt) {
137 assert(jt == JavaThread::current(), "Called by current thread");
138 Atomic::inc((jint*) &_exiting_threads_count);
140 oop threadObj = jt->threadObj();
141 if (threadObj != NULL && java_lang_Thread::is_daemon(threadObj)) {
142 Atomic::inc((jint*) &_exiting_daemon_threads_count);
143 }
144 }
146 // FIXME: JVMTI should call this function
147 Handle ThreadService::get_current_contended_monitor(JavaThread* thread) {
148 assert(thread != NULL, "should be non-NULL");
149 assert(Threads_lock->owned_by_self(), "must grab Threads_lock or be at safepoint");
151 ObjectMonitor *wait_obj = thread->current_waiting_monitor();
153 oop obj = NULL;
154 if (wait_obj != NULL) {
155 // thread is doing an Object.wait() call
156 obj = (oop) wait_obj->object();
157 assert(obj != NULL, "Object.wait() should have an object");
158 } else {
159 ObjectMonitor *enter_obj = thread->current_pending_monitor();
160 if (enter_obj != NULL) {
161 // thread is trying to enter() or raw_enter() an ObjectMonitor.
162 obj = (oop) enter_obj->object();
163 }
164 // If obj == NULL, then ObjectMonitor is raw which doesn't count.
165 }
167 Handle h(obj);
168 return h;
169 }
171 bool ThreadService::set_thread_monitoring_contention(bool flag) {
172 MutexLocker m(Management_lock);
174 bool prev = _thread_monitoring_contention_enabled;
175 _thread_monitoring_contention_enabled = flag;
177 return prev;
178 }
180 bool ThreadService::set_thread_cpu_time_enabled(bool flag) {
181 MutexLocker m(Management_lock);
183 bool prev = _thread_cpu_time_enabled;
184 _thread_cpu_time_enabled = flag;
186 return prev;
187 }
189 bool ThreadService::set_thread_allocated_memory_enabled(bool flag) {
190 MutexLocker m(Management_lock);
192 bool prev = _thread_allocated_memory_enabled;
193 _thread_allocated_memory_enabled = flag;
195 return prev;
196 }
198 // GC support
199 void ThreadService::oops_do(OopClosure* f) {
200 for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) {
201 dump->oops_do(f);
202 }
203 }
205 void ThreadService::metadata_do(void f(Metadata*)) {
206 for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) {
207 dump->metadata_do(f);
208 }
209 }
211 void ThreadService::add_thread_dump(ThreadDumpResult* dump) {
212 MutexLocker ml(Management_lock);
213 if (_threaddump_list == NULL) {
214 _threaddump_list = dump;
215 } else {
216 dump->set_next(_threaddump_list);
217 _threaddump_list = dump;
218 }
219 }
221 void ThreadService::remove_thread_dump(ThreadDumpResult* dump) {
222 MutexLocker ml(Management_lock);
224 ThreadDumpResult* prev = NULL;
225 bool found = false;
226 for (ThreadDumpResult* d = _threaddump_list; d != NULL; prev = d, d = d->next()) {
227 if (d == dump) {
228 if (prev == NULL) {
229 _threaddump_list = dump->next();
230 } else {
231 prev->set_next(dump->next());
232 }
233 found = true;
234 break;
235 }
236 }
237 assert(found, "The threaddump result to be removed must exist.");
238 }
240 // Dump stack trace of threads specified in the given threads array.
241 // Returns StackTraceElement[][] each element is the stack trace of a thread in
242 // the corresponding entry in the given threads array
243 Handle ThreadService::dump_stack_traces(GrowableArray<instanceHandle>* threads,
244 int num_threads,
245 TRAPS) {
246 assert(num_threads > 0, "just checking");
248 ThreadDumpResult dump_result;
249 VM_ThreadDump op(&dump_result,
250 threads,
251 num_threads,
252 -1, /* entire stack */
253 false, /* with locked monitors */
254 false /* with locked synchronizers */);
255 VMThread::execute(&op);
257 // Allocate the resulting StackTraceElement[][] object
259 ResourceMark rm(THREAD);
260 Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_StackTraceElement_array(), true, CHECK_NH);
261 ObjArrayKlass* ik = ObjArrayKlass::cast(k);
262 objArrayOop r = oopFactory::new_objArray(ik, num_threads, CHECK_NH);
263 objArrayHandle result_obj(THREAD, r);
265 int num_snapshots = dump_result.num_snapshots();
266 assert(num_snapshots == num_threads, "Must have num_threads thread snapshots");
267 int i = 0;
268 for (ThreadSnapshot* ts = dump_result.snapshots(); ts != NULL; i++, ts = ts->next()) {
269 ThreadStackTrace* stacktrace = ts->get_stack_trace();
270 if (stacktrace == NULL) {
271 // No stack trace
272 result_obj->obj_at_put(i, NULL);
273 } else {
274 // Construct an array of java/lang/StackTraceElement object
275 Handle backtrace_h = stacktrace->allocate_fill_stack_trace_element_array(CHECK_NH);
276 result_obj->obj_at_put(i, backtrace_h());
277 }
278 }
280 return result_obj;
281 }
283 void ThreadService::reset_contention_count_stat(JavaThread* thread) {
284 ThreadStatistics* stat = thread->get_thread_stat();
285 if (stat != NULL) {
286 stat->reset_count_stat();
287 }
288 }
290 void ThreadService::reset_contention_time_stat(JavaThread* thread) {
291 ThreadStatistics* stat = thread->get_thread_stat();
292 if (stat != NULL) {
293 stat->reset_time_stat();
294 }
295 }
297 // Find deadlocks involving object monitors and concurrent locks if concurrent_locks is true
298 DeadlockCycle* ThreadService::find_deadlocks_at_safepoint(bool concurrent_locks) {
299 // This code was modified from the original Threads::find_deadlocks code.
300 int globalDfn = 0, thisDfn;
301 ObjectMonitor* waitingToLockMonitor = NULL;
302 oop waitingToLockBlocker = NULL;
303 bool blocked_on_monitor = false;
304 JavaThread *currentThread, *previousThread;
305 int num_deadlocks = 0;
307 for (JavaThread* p = Threads::first(); p != NULL; p = p->next()) {
308 // Initialize the depth-first-number
309 p->set_depth_first_number(-1);
310 }
312 DeadlockCycle* deadlocks = NULL;
313 DeadlockCycle* last = NULL;
314 DeadlockCycle* cycle = new DeadlockCycle();
315 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
316 if (jt->depth_first_number() >= 0) {
317 // this thread was already visited
318 continue;
319 }
321 thisDfn = globalDfn;
322 jt->set_depth_first_number(globalDfn++);
323 previousThread = jt;
324 currentThread = jt;
326 cycle->reset();
328 // When there is a deadlock, all the monitors involved in the dependency
329 // cycle must be contended and heavyweight. So we only care about the
330 // heavyweight monitor a thread is waiting to lock.
331 waitingToLockMonitor = (ObjectMonitor*)jt->current_pending_monitor();
332 if (concurrent_locks) {
333 waitingToLockBlocker = jt->current_park_blocker();
334 }
335 while (waitingToLockMonitor != NULL || waitingToLockBlocker != NULL) {
336 cycle->add_thread(currentThread);
337 if (waitingToLockMonitor != NULL) {
338 address currentOwner = (address)waitingToLockMonitor->owner();
339 if (currentOwner != NULL) {
340 currentThread = Threads::owning_thread_from_monitor_owner(
341 currentOwner,
342 false /* no locking needed */);
343 if (currentThread == NULL) {
344 // This function is called at a safepoint so the JavaThread
345 // that owns waitingToLockMonitor should be findable, but
346 // if it is not findable, then the previous currentThread is
347 // blocked permanently. We record this as a deadlock.
348 num_deadlocks++;
350 cycle->set_deadlock(true);
352 // add this cycle to the deadlocks list
353 if (deadlocks == NULL) {
354 deadlocks = cycle;
355 } else {
356 last->set_next(cycle);
357 }
358 last = cycle;
359 cycle = new DeadlockCycle();
360 break;
361 }
362 }
363 } else {
364 if (concurrent_locks) {
365 if (waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) {
366 oop threadObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
367 currentThread = threadObj != NULL ? java_lang_Thread::thread(threadObj) : NULL;
368 } else {
369 currentThread = NULL;
370 }
371 }
372 }
374 if (currentThread == NULL) {
375 // No dependency on another thread
376 break;
377 }
378 if (currentThread->depth_first_number() < 0) {
379 // First visit to this thread
380 currentThread->set_depth_first_number(globalDfn++);
381 } else if (currentThread->depth_first_number() < thisDfn) {
382 // Thread already visited, and not on a (new) cycle
383 break;
384 } else if (currentThread == previousThread) {
385 // Self-loop, ignore
386 break;
387 } else {
388 // We have a (new) cycle
389 num_deadlocks++;
391 cycle->set_deadlock(true);
393 // add this cycle to the deadlocks list
394 if (deadlocks == NULL) {
395 deadlocks = cycle;
396 } else {
397 last->set_next(cycle);
398 }
399 last = cycle;
400 cycle = new DeadlockCycle();
401 break;
402 }
403 previousThread = currentThread;
404 waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
405 if (concurrent_locks) {
406 waitingToLockBlocker = currentThread->current_park_blocker();
407 }
408 }
410 }
411 delete cycle;
412 return deadlocks;
413 }
415 ThreadDumpResult::ThreadDumpResult() : _num_threads(0), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) {
417 // Create a new ThreadDumpResult object and append to the list.
418 // If GC happens before this function returns, Method*
419 // in the stack trace will be visited.
420 ThreadService::add_thread_dump(this);
421 }
423 ThreadDumpResult::ThreadDumpResult(int num_threads) : _num_threads(num_threads), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) {
424 // Create a new ThreadDumpResult object and append to the list.
425 // If GC happens before this function returns, oops
426 // will be visited.
427 ThreadService::add_thread_dump(this);
428 }
430 ThreadDumpResult::~ThreadDumpResult() {
431 ThreadService::remove_thread_dump(this);
433 // free all the ThreadSnapshot objects created during
434 // the VM_ThreadDump operation
435 ThreadSnapshot* ts = _snapshots;
436 while (ts != NULL) {
437 ThreadSnapshot* p = ts;
438 ts = ts->next();
439 delete p;
440 }
441 }
444 void ThreadDumpResult::add_thread_snapshot(ThreadSnapshot* ts) {
445 assert(_num_threads == 0 || _num_snapshots < _num_threads,
446 "_num_snapshots must be less than _num_threads");
447 _num_snapshots++;
448 if (_snapshots == NULL) {
449 _snapshots = ts;
450 } else {
451 _last->set_next(ts);
452 }
453 _last = ts;
454 }
456 void ThreadDumpResult::oops_do(OopClosure* f) {
457 for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) {
458 ts->oops_do(f);
459 }
460 }
462 void ThreadDumpResult::metadata_do(void f(Metadata*)) {
463 for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) {
464 ts->metadata_do(f);
465 }
466 }
468 StackFrameInfo::StackFrameInfo(javaVFrame* jvf, bool with_lock_info) {
469 _method = jvf->method();
470 _bci = jvf->bci();
471 _class_holder = _method->method_holder()->klass_holder();
472 _locked_monitors = NULL;
473 if (with_lock_info) {
474 ResourceMark rm;
475 GrowableArray<MonitorInfo*>* list = jvf->locked_monitors();
476 int length = list->length();
477 if (length > 0) {
478 _locked_monitors = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(length, true);
479 for (int i = 0; i < length; i++) {
480 MonitorInfo* monitor = list->at(i);
481 assert(monitor->owner(), "This monitor must have an owning object");
482 _locked_monitors->append(monitor->owner());
483 }
484 }
485 }
486 }
488 void StackFrameInfo::oops_do(OopClosure* f) {
489 if (_locked_monitors != NULL) {
490 int length = _locked_monitors->length();
491 for (int i = 0; i < length; i++) {
492 f->do_oop((oop*) _locked_monitors->adr_at(i));
493 }
494 }
495 f->do_oop(&_class_holder);
496 }
498 void StackFrameInfo::metadata_do(void f(Metadata*)) {
499 f(_method);
500 }
502 void StackFrameInfo::print_on(outputStream* st) const {
503 ResourceMark rm;
504 java_lang_Throwable::print_stack_element(st, method(), bci());
505 int len = (_locked_monitors != NULL ? _locked_monitors->length() : 0);
506 for (int i = 0; i < len; i++) {
507 oop o = _locked_monitors->at(i);
508 InstanceKlass* ik = InstanceKlass::cast(o->klass());
509 st->print_cr("\t- locked <" INTPTR_FORMAT "> (a %s)", (address)o, ik->external_name());
510 }
512 }
514 // Iterate through monitor cache to find JNI locked monitors
515 class InflatedMonitorsClosure: public MonitorClosure {
516 private:
517 ThreadStackTrace* _stack_trace;
518 Thread* _thread;
519 public:
520 InflatedMonitorsClosure(Thread* t, ThreadStackTrace* st) {
521 _thread = t;
522 _stack_trace = st;
523 }
524 void do_monitor(ObjectMonitor* mid) {
525 if (mid->owner() == _thread) {
526 oop object = (oop) mid->object();
527 if (!_stack_trace->is_owned_monitor_on_stack(object)) {
528 _stack_trace->add_jni_locked_monitor(object);
529 }
530 }
531 }
532 };
534 ThreadStackTrace::ThreadStackTrace(JavaThread* t, bool with_locked_monitors) {
535 _thread = t;
536 _frames = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<StackFrameInfo*>(INITIAL_ARRAY_SIZE, true);
537 _depth = 0;
538 _with_locked_monitors = with_locked_monitors;
539 if (_with_locked_monitors) {
540 _jni_locked_monitors = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(INITIAL_ARRAY_SIZE, true);
541 } else {
542 _jni_locked_monitors = NULL;
543 }
544 }
546 ThreadStackTrace::~ThreadStackTrace() {
547 for (int i = 0; i < _frames->length(); i++) {
548 delete _frames->at(i);
549 }
550 delete _frames;
551 if (_jni_locked_monitors != NULL) {
552 delete _jni_locked_monitors;
553 }
554 }
556 void ThreadStackTrace::dump_stack_at_safepoint(int maxDepth) {
557 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
559 if (_thread->has_last_Java_frame()) {
560 RegisterMap reg_map(_thread);
561 vframe* start_vf = _thread->last_java_vframe(®_map);
562 int count = 0;
563 for (vframe* f = start_vf; f; f = f->sender() ) {
564 if (f->is_java_frame()) {
565 javaVFrame* jvf = javaVFrame::cast(f);
566 add_stack_frame(jvf);
567 count++;
568 } else {
569 // Ignore non-Java frames
570 }
571 if (maxDepth > 0 && count == maxDepth) {
572 // Skip frames if more than maxDepth
573 break;
574 }
575 }
576 }
578 if (_with_locked_monitors) {
579 // Iterate inflated monitors and find monitors locked by this thread
580 // not found in the stack
581 InflatedMonitorsClosure imc(_thread, this);
582 ObjectSynchronizer::monitors_iterate(&imc);
583 }
584 }
587 bool ThreadStackTrace::is_owned_monitor_on_stack(oop object) {
588 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
590 bool found = false;
591 int num_frames = get_stack_depth();
592 for (int depth = 0; depth < num_frames; depth++) {
593 StackFrameInfo* frame = stack_frame_at(depth);
594 int len = frame->num_locked_monitors();
595 GrowableArray<oop>* locked_monitors = frame->locked_monitors();
596 for (int j = 0; j < len; j++) {
597 oop monitor = locked_monitors->at(j);
598 assert(monitor != NULL && monitor->is_instance(), "must be a Java object");
599 if (monitor == object) {
600 found = true;
601 break;
602 }
603 }
604 }
605 return found;
606 }
608 Handle ThreadStackTrace::allocate_fill_stack_trace_element_array(TRAPS) {
609 Klass* k = SystemDictionary::StackTraceElement_klass();
610 assert(k != NULL, "must be loaded in 1.4+");
611 instanceKlassHandle ik(THREAD, k);
613 // Allocate an array of java/lang/StackTraceElement object
614 objArrayOop ste = oopFactory::new_objArray(ik(), _depth, CHECK_NH);
615 objArrayHandle backtrace(THREAD, ste);
616 for (int j = 0; j < _depth; j++) {
617 StackFrameInfo* frame = _frames->at(j);
618 methodHandle mh(THREAD, frame->method());
619 oop element = java_lang_StackTraceElement::create(mh, frame->bci(), CHECK_NH);
620 backtrace->obj_at_put(j, element);
621 }
622 return backtrace;
623 }
625 void ThreadStackTrace::add_stack_frame(javaVFrame* jvf) {
626 StackFrameInfo* frame = new StackFrameInfo(jvf, _with_locked_monitors);
627 _frames->append(frame);
628 _depth++;
629 }
631 void ThreadStackTrace::oops_do(OopClosure* f) {
632 int length = _frames->length();
633 for (int i = 0; i < length; i++) {
634 _frames->at(i)->oops_do(f);
635 }
637 length = (_jni_locked_monitors != NULL ? _jni_locked_monitors->length() : 0);
638 for (int j = 0; j < length; j++) {
639 f->do_oop((oop*) _jni_locked_monitors->adr_at(j));
640 }
641 }
643 void ThreadStackTrace::metadata_do(void f(Metadata*)) {
644 int length = _frames->length();
645 for (int i = 0; i < length; i++) {
646 _frames->at(i)->metadata_do(f);
647 }
648 }
651 ConcurrentLocksDump::~ConcurrentLocksDump() {
652 if (_retain_map_on_free) {
653 return;
654 }
656 for (ThreadConcurrentLocks* t = _map; t != NULL;) {
657 ThreadConcurrentLocks* tcl = t;
658 t = t->next();
659 delete tcl;
660 }
661 }
663 void ConcurrentLocksDump::dump_at_safepoint() {
664 // dump all locked concurrent locks
665 assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
667 if (JDK_Version::is_gte_jdk16x_version()) {
668 ResourceMark rm;
670 GrowableArray<oop>* aos_objects = new GrowableArray<oop>(INITIAL_ARRAY_SIZE);
672 // Find all instances of AbstractOwnableSynchronizer
673 HeapInspection::find_instances_at_safepoint(SystemDictionary::abstract_ownable_synchronizer_klass(),
674 aos_objects);
675 // Build a map of thread to its owned AQS locks
676 build_map(aos_objects);
677 }
678 }
681 // build a map of JavaThread to all its owned AbstractOwnableSynchronizer
682 void ConcurrentLocksDump::build_map(GrowableArray<oop>* aos_objects) {
683 int length = aos_objects->length();
684 for (int i = 0; i < length; i++) {
685 oop o = aos_objects->at(i);
686 oop owner_thread_obj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(o);
687 if (owner_thread_obj != NULL) {
688 JavaThread* thread = java_lang_Thread::thread(owner_thread_obj);
689 assert(o->is_instance(), "Must be an instanceOop");
690 add_lock(thread, (instanceOop) o);
691 }
692 }
693 }
695 void ConcurrentLocksDump::add_lock(JavaThread* thread, instanceOop o) {
696 ThreadConcurrentLocks* tcl = thread_concurrent_locks(thread);
697 if (tcl != NULL) {
698 tcl->add_lock(o);
699 return;
700 }
702 // First owned lock found for this thread
703 tcl = new ThreadConcurrentLocks(thread);
704 tcl->add_lock(o);
705 if (_map == NULL) {
706 _map = tcl;
707 } else {
708 _last->set_next(tcl);
709 }
710 _last = tcl;
711 }
713 ThreadConcurrentLocks* ConcurrentLocksDump::thread_concurrent_locks(JavaThread* thread) {
714 for (ThreadConcurrentLocks* tcl = _map; tcl != NULL; tcl = tcl->next()) {
715 if (tcl->java_thread() == thread) {
716 return tcl;
717 }
718 }
719 return NULL;
720 }
722 void ConcurrentLocksDump::print_locks_on(JavaThread* t, outputStream* st) {
723 st->print_cr(" Locked ownable synchronizers:");
724 ThreadConcurrentLocks* tcl = thread_concurrent_locks(t);
725 GrowableArray<instanceOop>* locks = (tcl != NULL ? tcl->owned_locks() : NULL);
726 if (locks == NULL || locks->is_empty()) {
727 st->print_cr("\t- None");
728 st->cr();
729 return;
730 }
732 for (int i = 0; i < locks->length(); i++) {
733 instanceOop obj = locks->at(i);
734 InstanceKlass* ik = InstanceKlass::cast(obj->klass());
735 st->print_cr("\t- <" INTPTR_FORMAT "> (a %s)", (address)obj, ik->external_name());
736 }
737 st->cr();
738 }
740 ThreadConcurrentLocks::ThreadConcurrentLocks(JavaThread* thread) {
741 _thread = thread;
742 _owned_locks = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<instanceOop>(INITIAL_ARRAY_SIZE, true);
743 _next = NULL;
744 }
746 ThreadConcurrentLocks::~ThreadConcurrentLocks() {
747 delete _owned_locks;
748 }
750 void ThreadConcurrentLocks::add_lock(instanceOop o) {
751 _owned_locks->append(o);
752 }
754 void ThreadConcurrentLocks::oops_do(OopClosure* f) {
755 int length = _owned_locks->length();
756 for (int i = 0; i < length; i++) {
757 f->do_oop((oop*) _owned_locks->adr_at(i));
758 }
759 }
761 ThreadStatistics::ThreadStatistics() {
762 _contended_enter_count = 0;
763 _monitor_wait_count = 0;
764 _sleep_count = 0;
765 _count_pending_reset = false;
766 _timer_pending_reset = false;
767 memset((void*) _perf_recursion_counts, 0, sizeof(_perf_recursion_counts));
768 }
770 ThreadSnapshot::ThreadSnapshot(JavaThread* thread) {
771 _thread = thread;
772 _threadObj = thread->threadObj();
773 _stack_trace = NULL;
774 _concurrent_locks = NULL;
775 _next = NULL;
777 ThreadStatistics* stat = thread->get_thread_stat();
778 _contended_enter_ticks = stat->contended_enter_ticks();
779 _contended_enter_count = stat->contended_enter_count();
780 _monitor_wait_ticks = stat->monitor_wait_ticks();
781 _monitor_wait_count = stat->monitor_wait_count();
782 _sleep_ticks = stat->sleep_ticks();
783 _sleep_count = stat->sleep_count();
785 _blocker_object = NULL;
786 _blocker_object_owner = NULL;
788 _thread_status = java_lang_Thread::get_thread_status(_threadObj);
789 _is_ext_suspended = thread->is_being_ext_suspended();
790 _is_in_native = (thread->thread_state() == _thread_in_native);
792 if (_thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER ||
793 _thread_status == java_lang_Thread::IN_OBJECT_WAIT ||
794 _thread_status == java_lang_Thread::IN_OBJECT_WAIT_TIMED) {
796 Handle obj = ThreadService::get_current_contended_monitor(thread);
797 if (obj() == NULL) {
798 // monitor no longer exists; thread is not blocked
799 _thread_status = java_lang_Thread::RUNNABLE;
800 } else {
801 _blocker_object = obj();
802 JavaThread* owner = ObjectSynchronizer::get_lock_owner(obj, false);
803 if ((owner == NULL && _thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER)
804 || (owner != NULL && owner->is_attaching_via_jni())) {
805 // ownership information of the monitor is not available
806 // (may no longer be owned or releasing to some other thread)
807 // make this thread in RUNNABLE state.
808 // And when the owner thread is in attaching state, the java thread
809 // is not completely initialized. For example thread name and id
810 // and may not be set, so hide the attaching thread.
811 _thread_status = java_lang_Thread::RUNNABLE;
812 _blocker_object = NULL;
813 } else if (owner != NULL) {
814 _blocker_object_owner = owner->threadObj();
815 }
816 }
817 }
819 // Support for JSR-166 locks
820 if (JDK_Version::current().supports_thread_park_blocker() &&
821 (_thread_status == java_lang_Thread::PARKED ||
822 _thread_status == java_lang_Thread::PARKED_TIMED)) {
824 _blocker_object = thread->current_park_blocker();
825 if (_blocker_object != NULL && _blocker_object->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) {
826 _blocker_object_owner = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(_blocker_object);
827 }
828 }
829 }
831 ThreadSnapshot::~ThreadSnapshot() {
832 delete _stack_trace;
833 delete _concurrent_locks;
834 }
836 void ThreadSnapshot::dump_stack_at_safepoint(int max_depth, bool with_locked_monitors) {
837 _stack_trace = new ThreadStackTrace(_thread, with_locked_monitors);
838 _stack_trace->dump_stack_at_safepoint(max_depth);
839 }
842 void ThreadSnapshot::oops_do(OopClosure* f) {
843 f->do_oop(&_threadObj);
844 f->do_oop(&_blocker_object);
845 f->do_oop(&_blocker_object_owner);
846 if (_stack_trace != NULL) {
847 _stack_trace->oops_do(f);
848 }
849 if (_concurrent_locks != NULL) {
850 _concurrent_locks->oops_do(f);
851 }
852 }
854 void ThreadSnapshot::metadata_do(void f(Metadata*)) {
855 if (_stack_trace != NULL) {
856 _stack_trace->metadata_do(f);
857 }
858 }
861 DeadlockCycle::DeadlockCycle() {
862 _is_deadlock = false;
863 _threads = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<JavaThread*>(INITIAL_ARRAY_SIZE, true);
864 _next = NULL;
865 }
867 DeadlockCycle::~DeadlockCycle() {
868 delete _threads;
869 }
871 void DeadlockCycle::print_on(outputStream* st) const {
872 st->cr();
873 st->print_cr("Found one Java-level deadlock:");
874 st->print("=============================");
876 JavaThread* currentThread;
877 ObjectMonitor* waitingToLockMonitor;
878 oop waitingToLockBlocker;
879 int len = _threads->length();
880 for (int i = 0; i < len; i++) {
881 currentThread = _threads->at(i);
882 waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
883 waitingToLockBlocker = currentThread->current_park_blocker();
884 st->cr();
885 st->print_cr("\"%s\":", currentThread->get_thread_name());
886 const char* owner_desc = ",\n which is held by";
887 if (waitingToLockMonitor != NULL) {
888 st->print(" waiting to lock monitor " INTPTR_FORMAT, waitingToLockMonitor);
889 oop obj = (oop)waitingToLockMonitor->object();
890 if (obj != NULL) {
891 st->print(" (object "INTPTR_FORMAT ", a %s)", (address)obj,
892 (InstanceKlass::cast(obj->klass()))->external_name());
894 if (!currentThread->current_pending_monitor_is_from_java()) {
895 owner_desc = "\n in JNI, which is held by";
896 }
897 } else {
898 // No Java object associated - a JVMTI raw monitor
899 owner_desc = " (JVMTI raw monitor),\n which is held by";
900 }
901 currentThread = Threads::owning_thread_from_monitor_owner(
902 (address)waitingToLockMonitor->owner(),
903 false /* no locking needed */);
904 if (currentThread == NULL) {
905 // The deadlock was detected at a safepoint so the JavaThread
906 // that owns waitingToLockMonitor should be findable, but
907 // if it is not findable, then the previous currentThread is
908 // blocked permanently.
909 st->print("%s UNKNOWN_owner_addr=" PTR_FORMAT, owner_desc,
910 (address)waitingToLockMonitor->owner());
911 continue;
912 }
913 } else {
914 st->print(" waiting for ownable synchronizer " INTPTR_FORMAT ", (a %s)",
915 (address)waitingToLockBlocker,
916 (InstanceKlass::cast(waitingToLockBlocker->klass()))->external_name());
917 assert(waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass()),
918 "Must be an AbstractOwnableSynchronizer");
919 oop ownerObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
920 currentThread = java_lang_Thread::thread(ownerObj);
921 }
922 st->print("%s \"%s\"", owner_desc, currentThread->get_thread_name());
923 }
925 st->cr();
926 st->cr();
928 // Print stack traces
929 bool oldJavaMonitorsInStackTrace = JavaMonitorsInStackTrace;
930 JavaMonitorsInStackTrace = true;
931 st->print_cr("Java stack information for the threads listed above:");
932 st->print_cr("===================================================");
933 for (int j = 0; j < len; j++) {
934 currentThread = _threads->at(j);
935 st->print_cr("\"%s\":", currentThread->get_thread_name());
936 currentThread->print_stack_on(st);
937 }
938 JavaMonitorsInStackTrace = oldJavaMonitorsInStackTrace;
939 }
941 ThreadsListEnumerator::ThreadsListEnumerator(Thread* cur_thread,
942 bool include_jvmti_agent_threads,
943 bool include_jni_attaching_threads) {
944 assert(cur_thread == Thread::current(), "Check current thread");
946 int init_size = ThreadService::get_live_thread_count();
947 _threads_array = new GrowableArray<instanceHandle>(init_size);
949 MutexLockerEx ml(Threads_lock);
951 for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
952 // skips JavaThreads in the process of exiting
953 // and also skips VM internal JavaThreads
954 // Threads in _thread_new or _thread_new_trans state are included.
955 // i.e. threads have been started but not yet running.
956 if (jt->threadObj() == NULL ||
957 jt->is_exiting() ||
958 !java_lang_Thread::is_alive(jt->threadObj()) ||
959 jt->is_hidden_from_external_view()) {
960 continue;
961 }
963 // skip agent threads
964 if (!include_jvmti_agent_threads && jt->is_jvmti_agent_thread()) {
965 continue;
966 }
968 // skip jni threads in the process of attaching
969 if (!include_jni_attaching_threads && jt->is_attaching_via_jni()) {
970 continue;
971 }
973 instanceHandle h(cur_thread, (instanceOop) jt->threadObj());
974 _threads_array->append(h);
975 }
976 }