1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/services/threadService.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,885 @@
1.4 +/*
1.5 + * Copyright 2003-2007 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +# include "incls/_precompiled.incl"
1.29 +# include "incls/_threadService.cpp.incl"
1.30 +
1.31 +// TODO: we need to define a naming convention for perf counters
1.32 +// to distinguish counters for:
1.33 +// - standard JSR174 use
1.34 +// - Hotspot extension (public and committed)
1.35 +// - Hotspot extension (private/internal and uncommitted)
1.36 +
1.37 +// Default is disabled.
1.38 +bool ThreadService::_thread_monitoring_contention_enabled = false;
1.39 +bool ThreadService::_thread_cpu_time_enabled = false;
1.40 +
1.41 +PerfCounter* ThreadService::_total_threads_count = NULL;
1.42 +PerfVariable* ThreadService::_live_threads_count = NULL;
1.43 +PerfVariable* ThreadService::_peak_threads_count = NULL;
1.44 +PerfVariable* ThreadService::_daemon_threads_count = NULL;
1.45 +volatile int ThreadService::_exiting_threads_count = 0;
1.46 +volatile int ThreadService::_exiting_daemon_threads_count = 0;
1.47 +
1.48 +ThreadDumpResult* ThreadService::_threaddump_list = NULL;
1.49 +
1.50 +static const int INITIAL_ARRAY_SIZE = 10;
1.51 +
1.52 +void ThreadService::init() {
1.53 + EXCEPTION_MARK;
1.54 +
1.55 + // These counters are for java.lang.management API support.
1.56 + // They are created even if -XX:-UsePerfData is set and in
1.57 + // that case, they will be allocated on C heap.
1.58 +
1.59 + _total_threads_count =
1.60 + PerfDataManager::create_counter(JAVA_THREADS, "started",
1.61 + PerfData::U_Events, CHECK);
1.62 +
1.63 + _live_threads_count =
1.64 + PerfDataManager::create_variable(JAVA_THREADS, "live",
1.65 + PerfData::U_None, CHECK);
1.66 +
1.67 + _peak_threads_count =
1.68 + PerfDataManager::create_variable(JAVA_THREADS, "livePeak",
1.69 + PerfData::U_None, CHECK);
1.70 +
1.71 + _daemon_threads_count =
1.72 + PerfDataManager::create_variable(JAVA_THREADS, "daemon",
1.73 + PerfData::U_None, CHECK);
1.74 +
1.75 + if (os::is_thread_cpu_time_supported()) {
1.76 + _thread_cpu_time_enabled = true;
1.77 + }
1.78 +}
1.79 +
1.80 +void ThreadService::reset_peak_thread_count() {
1.81 + // Acquire the lock to update the peak thread count
1.82 + // to synchronize with thread addition and removal.
1.83 + MutexLockerEx mu(Threads_lock);
1.84 + _peak_threads_count->set_value(get_live_thread_count());
1.85 +}
1.86 +
1.87 +void ThreadService::add_thread(JavaThread* thread, bool daemon) {
1.88 + // Do not count VM internal or JVMTI agent threads
1.89 + if (thread->is_hidden_from_external_view() ||
1.90 + thread->is_jvmti_agent_thread()) {
1.91 + return;
1.92 + }
1.93 +
1.94 + _total_threads_count->inc();
1.95 + _live_threads_count->inc();
1.96 +
1.97 + if (_live_threads_count->get_value() > _peak_threads_count->get_value()) {
1.98 + _peak_threads_count->set_value(_live_threads_count->get_value());
1.99 + }
1.100 +
1.101 + if (daemon) {
1.102 + _daemon_threads_count->inc();
1.103 + }
1.104 +}
1.105 +
1.106 +void ThreadService::remove_thread(JavaThread* thread, bool daemon) {
1.107 + Atomic::dec((jint*) &_exiting_threads_count);
1.108 +
1.109 + if (thread->is_hidden_from_external_view() ||
1.110 + thread->is_jvmti_agent_thread()) {
1.111 + return;
1.112 + }
1.113 +
1.114 + _live_threads_count->set_value(_live_threads_count->get_value() - 1);
1.115 +
1.116 + if (daemon) {
1.117 + _daemon_threads_count->set_value(_daemon_threads_count->get_value() - 1);
1.118 + Atomic::dec((jint*) &_exiting_daemon_threads_count);
1.119 + }
1.120 +}
1.121 +
1.122 +void ThreadService::current_thread_exiting(JavaThread* jt) {
1.123 + assert(jt == JavaThread::current(), "Called by current thread");
1.124 + Atomic::inc((jint*) &_exiting_threads_count);
1.125 +
1.126 + oop threadObj = jt->threadObj();
1.127 + if (threadObj != NULL && java_lang_Thread::is_daemon(threadObj)) {
1.128 + Atomic::inc((jint*) &_exiting_daemon_threads_count);
1.129 + }
1.130 +}
1.131 +
1.132 +// FIXME: JVMTI should call this function
1.133 +Handle ThreadService::get_current_contended_monitor(JavaThread* thread) {
1.134 + assert(thread != NULL, "should be non-NULL");
1.135 + assert(Threads_lock->owned_by_self(), "must grab Threads_lock or be at safepoint");
1.136 +
1.137 + ObjectMonitor *wait_obj = thread->current_waiting_monitor();
1.138 +
1.139 + oop obj = NULL;
1.140 + if (wait_obj != NULL) {
1.141 + // thread is doing an Object.wait() call
1.142 + obj = (oop) wait_obj->object();
1.143 + assert(obj != NULL, "Object.wait() should have an object");
1.144 + } else {
1.145 + ObjectMonitor *enter_obj = thread->current_pending_monitor();
1.146 + if (enter_obj != NULL) {
1.147 + // thread is trying to enter() or raw_enter() an ObjectMonitor.
1.148 + obj = (oop) enter_obj->object();
1.149 + }
1.150 + // If obj == NULL, then ObjectMonitor is raw which doesn't count.
1.151 + }
1.152 +
1.153 + Handle h(obj);
1.154 + return h;
1.155 +}
1.156 +
1.157 +bool ThreadService::set_thread_monitoring_contention(bool flag) {
1.158 + MutexLocker m(Management_lock);
1.159 +
1.160 + bool prev = _thread_monitoring_contention_enabled;
1.161 + _thread_monitoring_contention_enabled = flag;
1.162 +
1.163 + return prev;
1.164 +}
1.165 +
1.166 +bool ThreadService::set_thread_cpu_time_enabled(bool flag) {
1.167 + MutexLocker m(Management_lock);
1.168 +
1.169 + bool prev = _thread_cpu_time_enabled;
1.170 + _thread_cpu_time_enabled = flag;
1.171 +
1.172 + return prev;
1.173 +}
1.174 +
1.175 +// GC support
1.176 +void ThreadService::oops_do(OopClosure* f) {
1.177 + for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) {
1.178 + dump->oops_do(f);
1.179 + }
1.180 +}
1.181 +
1.182 +void ThreadService::add_thread_dump(ThreadDumpResult* dump) {
1.183 + MutexLocker ml(Management_lock);
1.184 + if (_threaddump_list == NULL) {
1.185 + _threaddump_list = dump;
1.186 + } else {
1.187 + dump->set_next(_threaddump_list);
1.188 + _threaddump_list = dump;
1.189 + }
1.190 +}
1.191 +
1.192 +void ThreadService::remove_thread_dump(ThreadDumpResult* dump) {
1.193 + MutexLocker ml(Management_lock);
1.194 +
1.195 + ThreadDumpResult* prev = NULL;
1.196 + bool found = false;
1.197 + for (ThreadDumpResult* d = _threaddump_list; d != NULL; prev = d, d = d->next()) {
1.198 + if (d == dump) {
1.199 + if (prev == NULL) {
1.200 + _threaddump_list = dump->next();
1.201 + } else {
1.202 + prev->set_next(dump->next());
1.203 + }
1.204 + found = true;
1.205 + break;
1.206 + }
1.207 + }
1.208 + assert(found, "The threaddump result to be removed must exist.");
1.209 +}
1.210 +
1.211 +// Dump stack trace of threads specified in the given threads array.
1.212 +// Returns StackTraceElement[][] each element is the stack trace of a thread in
1.213 +// the corresponding entry in the given threads array
1.214 +Handle ThreadService::dump_stack_traces(GrowableArray<instanceHandle>* threads,
1.215 + int num_threads,
1.216 + TRAPS) {
1.217 + assert(num_threads > 0, "just checking");
1.218 +
1.219 + ThreadDumpResult dump_result;
1.220 + VM_ThreadDump op(&dump_result,
1.221 + threads,
1.222 + num_threads,
1.223 + -1, /* entire stack */
1.224 + false, /* with locked monitors */
1.225 + false /* with locked synchronizers */);
1.226 + VMThread::execute(&op);
1.227 +
1.228 + // Allocate the resulting StackTraceElement[][] object
1.229 +
1.230 + ResourceMark rm(THREAD);
1.231 + klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_StackTraceElement_array(), true, CHECK_NH);
1.232 + objArrayKlassHandle ik (THREAD, k);
1.233 + objArrayOop r = oopFactory::new_objArray(ik(), num_threads, CHECK_NH);
1.234 + objArrayHandle result_obj(THREAD, r);
1.235 +
1.236 + int num_snapshots = dump_result.num_snapshots();
1.237 + assert(num_snapshots == num_threads, "Must have num_threads thread snapshots");
1.238 + int i = 0;
1.239 + for (ThreadSnapshot* ts = dump_result.snapshots(); ts != NULL; i++, ts = ts->next()) {
1.240 + ThreadStackTrace* stacktrace = ts->get_stack_trace();
1.241 + if (stacktrace == NULL) {
1.242 + // No stack trace
1.243 + result_obj->obj_at_put(i, NULL);
1.244 + } else {
1.245 + // Construct an array of java/lang/StackTraceElement object
1.246 + Handle backtrace_h = stacktrace->allocate_fill_stack_trace_element_array(CHECK_NH);
1.247 + result_obj->obj_at_put(i, backtrace_h());
1.248 + }
1.249 + }
1.250 +
1.251 + return result_obj;
1.252 +}
1.253 +
1.254 +void ThreadService::reset_contention_count_stat(JavaThread* thread) {
1.255 + ThreadStatistics* stat = thread->get_thread_stat();
1.256 + if (stat != NULL) {
1.257 + stat->reset_count_stat();
1.258 + }
1.259 +}
1.260 +
1.261 +void ThreadService::reset_contention_time_stat(JavaThread* thread) {
1.262 + ThreadStatistics* stat = thread->get_thread_stat();
1.263 + if (stat != NULL) {
1.264 + stat->reset_time_stat();
1.265 + }
1.266 +}
1.267 +
1.268 +// Find deadlocks involving object monitors and concurrent locks if concurrent_locks is true
1.269 +DeadlockCycle* ThreadService::find_deadlocks_at_safepoint(bool concurrent_locks) {
1.270 + // This code was modified from the original Threads::find_deadlocks code.
1.271 + int globalDfn = 0, thisDfn;
1.272 + ObjectMonitor* waitingToLockMonitor = NULL;
1.273 + oop waitingToLockBlocker = NULL;
1.274 + bool blocked_on_monitor = false;
1.275 + JavaThread *currentThread, *previousThread;
1.276 + int num_deadlocks = 0;
1.277 +
1.278 + for (JavaThread* p = Threads::first(); p != NULL; p = p->next()) {
1.279 + // Initialize the depth-first-number
1.280 + p->set_depth_first_number(-1);
1.281 + }
1.282 +
1.283 + DeadlockCycle* deadlocks = NULL;
1.284 + DeadlockCycle* last = NULL;
1.285 + DeadlockCycle* cycle = new DeadlockCycle();
1.286 + for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
1.287 + if (jt->depth_first_number() >= 0) {
1.288 + // this thread was already visited
1.289 + continue;
1.290 + }
1.291 +
1.292 + thisDfn = globalDfn;
1.293 + jt->set_depth_first_number(globalDfn++);
1.294 + previousThread = jt;
1.295 + currentThread = jt;
1.296 +
1.297 + cycle->reset();
1.298 +
1.299 + // When there is a deadlock, all the monitors involved in the dependency
1.300 + // cycle must be contended and heavyweight. So we only care about the
1.301 + // heavyweight monitor a thread is waiting to lock.
1.302 + waitingToLockMonitor = (ObjectMonitor*)jt->current_pending_monitor();
1.303 + if (concurrent_locks) {
1.304 + waitingToLockBlocker = jt->current_park_blocker();
1.305 + }
1.306 + while (waitingToLockMonitor != NULL || waitingToLockBlocker != NULL) {
1.307 + cycle->add_thread(currentThread);
1.308 + if (waitingToLockMonitor != NULL) {
1.309 + currentThread = Threads::owning_thread_from_monitor_owner((address)waitingToLockMonitor->owner(),
1.310 + false /* no locking needed */);
1.311 + } else {
1.312 + if (concurrent_locks) {
1.313 + if (waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) {
1.314 + oop threadObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
1.315 + currentThread = threadObj != NULL ? java_lang_Thread::thread(threadObj) : NULL;
1.316 + } else {
1.317 + currentThread = NULL;
1.318 + }
1.319 + }
1.320 + }
1.321 +
1.322 + if (currentThread == NULL) {
1.323 + // No dependency on another thread
1.324 + break;
1.325 + }
1.326 + if (currentThread->depth_first_number() < 0) {
1.327 + // First visit to this thread
1.328 + currentThread->set_depth_first_number(globalDfn++);
1.329 + } else if (currentThread->depth_first_number() < thisDfn) {
1.330 + // Thread already visited, and not on a (new) cycle
1.331 + break;
1.332 + } else if (currentThread == previousThread) {
1.333 + // Self-loop, ignore
1.334 + break;
1.335 + } else {
1.336 + // We have a (new) cycle
1.337 + num_deadlocks++;
1.338 +
1.339 + cycle->set_deadlock(true);
1.340 +
1.341 + // add this cycle to the deadlocks list
1.342 + if (deadlocks == NULL) {
1.343 + deadlocks = cycle;
1.344 + } else {
1.345 + last->set_next(cycle);
1.346 + }
1.347 + last = cycle;
1.348 + cycle = new DeadlockCycle();
1.349 + break;
1.350 + }
1.351 + previousThread = currentThread;
1.352 + waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
1.353 + if (concurrent_locks) {
1.354 + waitingToLockBlocker = currentThread->current_park_blocker();
1.355 + }
1.356 + }
1.357 +
1.358 + }
1.359 +
1.360 + return deadlocks;
1.361 +}
1.362 +
1.363 +ThreadDumpResult::ThreadDumpResult() : _num_threads(0), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) {
1.364 +
1.365 + // Create a new ThreadDumpResult object and append to the list.
1.366 + // If GC happens before this function returns, methodOop
1.367 + // in the stack trace will be visited.
1.368 + ThreadService::add_thread_dump(this);
1.369 +}
1.370 +
1.371 +ThreadDumpResult::ThreadDumpResult(int num_threads) : _num_threads(num_threads), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) {
1.372 + // Create a new ThreadDumpResult object and append to the list.
1.373 + // If GC happens before this function returns, oops
1.374 + // will be visited.
1.375 + ThreadService::add_thread_dump(this);
1.376 +}
1.377 +
1.378 +ThreadDumpResult::~ThreadDumpResult() {
1.379 + ThreadService::remove_thread_dump(this);
1.380 +
1.381 + // free all the ThreadSnapshot objects created during
1.382 + // the VM_ThreadDump operation
1.383 + ThreadSnapshot* ts = _snapshots;
1.384 + while (ts != NULL) {
1.385 + ThreadSnapshot* p = ts;
1.386 + ts = ts->next();
1.387 + delete p;
1.388 + }
1.389 +}
1.390 +
1.391 +
1.392 +void ThreadDumpResult::add_thread_snapshot(ThreadSnapshot* ts) {
1.393 + assert(_num_threads == 0 || _num_snapshots < _num_threads,
1.394 + "_num_snapshots must be less than _num_threads");
1.395 + _num_snapshots++;
1.396 + if (_snapshots == NULL) {
1.397 + _snapshots = ts;
1.398 + } else {
1.399 + _last->set_next(ts);
1.400 + }
1.401 + _last = ts;
1.402 +}
1.403 +
1.404 +void ThreadDumpResult::oops_do(OopClosure* f) {
1.405 + for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) {
1.406 + ts->oops_do(f);
1.407 + }
1.408 +}
1.409 +
1.410 +StackFrameInfo::StackFrameInfo(javaVFrame* jvf, bool with_lock_info) {
1.411 + _method = jvf->method();
1.412 + _bci = jvf->bci();
1.413 + _locked_monitors = NULL;
1.414 + if (with_lock_info) {
1.415 + ResourceMark rm;
1.416 + GrowableArray<MonitorInfo*>* list = jvf->locked_monitors();
1.417 + int length = list->length();
1.418 + if (length > 0) {
1.419 + _locked_monitors = new (ResourceObj::C_HEAP) GrowableArray<oop>(length, true);
1.420 + for (int i = 0; i < length; i++) {
1.421 + MonitorInfo* monitor = list->at(i);
1.422 + assert(monitor->owner(), "This monitor must have an owning object");
1.423 + _locked_monitors->append(monitor->owner());
1.424 + }
1.425 + }
1.426 + }
1.427 +}
1.428 +
1.429 +void StackFrameInfo::oops_do(OopClosure* f) {
1.430 + f->do_oop((oop*) &_method);
1.431 + if (_locked_monitors != NULL) {
1.432 + int length = _locked_monitors->length();
1.433 + for (int i = 0; i < length; i++) {
1.434 + f->do_oop((oop*) _locked_monitors->adr_at(i));
1.435 + }
1.436 + }
1.437 +}
1.438 +
1.439 +void StackFrameInfo::print_on(outputStream* st) const {
1.440 + ResourceMark rm;
1.441 + java_lang_Throwable::print_stack_element(st, method(), bci());
1.442 + int len = (_locked_monitors != NULL ? _locked_monitors->length() : 0);
1.443 + for (int i = 0; i < len; i++) {
1.444 + oop o = _locked_monitors->at(i);
1.445 + instanceKlass* ik = instanceKlass::cast(o->klass());
1.446 + st->print_cr("\t- locked <" INTPTR_FORMAT "> (a %s)", (address)o, ik->external_name());
1.447 + }
1.448 +
1.449 +}
1.450 +
1.451 +// Iterate through monitor cache to find JNI locked monitors
1.452 +class InflatedMonitorsClosure: public MonitorClosure {
1.453 +private:
1.454 + ThreadStackTrace* _stack_trace;
1.455 + Thread* _thread;
1.456 +public:
1.457 + InflatedMonitorsClosure(Thread* t, ThreadStackTrace* st) {
1.458 + _thread = t;
1.459 + _stack_trace = st;
1.460 + }
1.461 + void do_monitor(ObjectMonitor* mid) {
1.462 + if (mid->owner() == _thread) {
1.463 + oop object = (oop) mid->object();
1.464 + if (!_stack_trace->is_owned_monitor_on_stack(object)) {
1.465 + _stack_trace->add_jni_locked_monitor(object);
1.466 + }
1.467 + }
1.468 + }
1.469 +};
1.470 +
1.471 +ThreadStackTrace::ThreadStackTrace(JavaThread* t, bool with_locked_monitors) {
1.472 + _thread = t;
1.473 + _frames = new (ResourceObj::C_HEAP) GrowableArray<StackFrameInfo*>(INITIAL_ARRAY_SIZE, true);
1.474 + _depth = 0;
1.475 + _with_locked_monitors = with_locked_monitors;
1.476 + if (_with_locked_monitors) {
1.477 + _jni_locked_monitors = new (ResourceObj::C_HEAP) GrowableArray<oop>(INITIAL_ARRAY_SIZE, true);
1.478 + } else {
1.479 + _jni_locked_monitors = NULL;
1.480 + }
1.481 +}
1.482 +
1.483 +ThreadStackTrace::~ThreadStackTrace() {
1.484 + for (int i = 0; i < _frames->length(); i++) {
1.485 + delete _frames->at(i);
1.486 + }
1.487 + delete _frames;
1.488 + if (_jni_locked_monitors != NULL) {
1.489 + delete _jni_locked_monitors;
1.490 + }
1.491 +}
1.492 +
1.493 +void ThreadStackTrace::dump_stack_at_safepoint(int maxDepth) {
1.494 + assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1.495 +
1.496 + if (_thread->has_last_Java_frame()) {
1.497 + RegisterMap reg_map(_thread);
1.498 + vframe* start_vf = _thread->last_java_vframe(®_map);
1.499 + int count = 0;
1.500 + for (vframe* f = start_vf; f; f = f->sender() ) {
1.501 + if (f->is_java_frame()) {
1.502 + javaVFrame* jvf = javaVFrame::cast(f);
1.503 + add_stack_frame(jvf);
1.504 + count++;
1.505 + } else {
1.506 + // Ignore non-Java frames
1.507 + }
1.508 + if (maxDepth > 0 && count == maxDepth) {
1.509 + // Skip frames if more than maxDepth
1.510 + break;
1.511 + }
1.512 + }
1.513 + }
1.514 +
1.515 + if (_with_locked_monitors) {
1.516 + // Iterate inflated monitors and find monitors locked by this thread
1.517 + // not found in the stack
1.518 + InflatedMonitorsClosure imc(_thread, this);
1.519 + ObjectSynchronizer::monitors_iterate(&imc);
1.520 + }
1.521 +}
1.522 +
1.523 +
1.524 +bool ThreadStackTrace::is_owned_monitor_on_stack(oop object) {
1.525 + assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1.526 +
1.527 + bool found = false;
1.528 + int num_frames = get_stack_depth();
1.529 + for (int depth = 0; depth < num_frames; depth++) {
1.530 + StackFrameInfo* frame = stack_frame_at(depth);
1.531 + int len = frame->num_locked_monitors();
1.532 + GrowableArray<oop>* locked_monitors = frame->locked_monitors();
1.533 + for (int j = 0; j < len; j++) {
1.534 + oop monitor = locked_monitors->at(j);
1.535 + assert(monitor != NULL && monitor->is_instance(), "must be a Java object");
1.536 + if (monitor == object) {
1.537 + found = true;
1.538 + break;
1.539 + }
1.540 + }
1.541 + }
1.542 + return found;
1.543 +}
1.544 +
1.545 +Handle ThreadStackTrace::allocate_fill_stack_trace_element_array(TRAPS) {
1.546 + klassOop k = SystemDictionary::stackTraceElement_klass();
1.547 + instanceKlassHandle ik(THREAD, k);
1.548 +
1.549 + // Allocate an array of java/lang/StackTraceElement object
1.550 + objArrayOop ste = oopFactory::new_objArray(ik(), _depth, CHECK_NH);
1.551 + objArrayHandle backtrace(THREAD, ste);
1.552 + for (int j = 0; j < _depth; j++) {
1.553 + StackFrameInfo* frame = _frames->at(j);
1.554 + methodHandle mh(THREAD, frame->method());
1.555 + oop element = java_lang_StackTraceElement::create(mh, frame->bci(), CHECK_NH);
1.556 + backtrace->obj_at_put(j, element);
1.557 + }
1.558 + return backtrace;
1.559 +}
1.560 +
1.561 +void ThreadStackTrace::add_stack_frame(javaVFrame* jvf) {
1.562 + StackFrameInfo* frame = new StackFrameInfo(jvf, _with_locked_monitors);
1.563 + _frames->append(frame);
1.564 + _depth++;
1.565 +}
1.566 +
1.567 +void ThreadStackTrace::oops_do(OopClosure* f) {
1.568 + int length = _frames->length();
1.569 + for (int i = 0; i < length; i++) {
1.570 + _frames->at(i)->oops_do(f);
1.571 + }
1.572 +
1.573 + length = (_jni_locked_monitors != NULL ? _jni_locked_monitors->length() : 0);
1.574 + for (int j = 0; j < length; j++) {
1.575 + f->do_oop((oop*) _jni_locked_monitors->adr_at(j));
1.576 + }
1.577 +}
1.578 +
1.579 +ConcurrentLocksDump::~ConcurrentLocksDump() {
1.580 + if (_retain_map_on_free) {
1.581 + return;
1.582 + }
1.583 +
1.584 + for (ThreadConcurrentLocks* t = _map; t != NULL;) {
1.585 + ThreadConcurrentLocks* tcl = t;
1.586 + t = t->next();
1.587 + delete tcl;
1.588 + }
1.589 +}
1.590 +
1.591 +void ConcurrentLocksDump::dump_at_safepoint() {
1.592 + // dump all locked concurrent locks
1.593 + assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1.594 +
1.595 + if (JDK_Version::is_gte_jdk16x_version()) {
1.596 + ResourceMark rm;
1.597 +
1.598 + GrowableArray<oop>* aos_objects = new GrowableArray<oop>(INITIAL_ARRAY_SIZE);
1.599 +
1.600 + // Find all instances of AbstractOwnableSynchronizer
1.601 + HeapInspection::find_instances_at_safepoint(SystemDictionary::abstract_ownable_synchronizer_klass(),
1.602 + aos_objects);
1.603 + // Build a map of thread to its owned AQS locks
1.604 + build_map(aos_objects);
1.605 + }
1.606 +}
1.607 +
1.608 +
1.609 +// build a map of JavaThread to all its owned AbstractOwnableSynchronizer
1.610 +void ConcurrentLocksDump::build_map(GrowableArray<oop>* aos_objects) {
1.611 + int length = aos_objects->length();
1.612 + for (int i = 0; i < length; i++) {
1.613 + oop o = aos_objects->at(i);
1.614 + oop owner_thread_obj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(o);
1.615 + if (owner_thread_obj != NULL) {
1.616 + JavaThread* thread = java_lang_Thread::thread(owner_thread_obj);
1.617 + assert(o->is_instance(), "Must be an instanceOop");
1.618 + add_lock(thread, (instanceOop) o);
1.619 + }
1.620 + }
1.621 +}
1.622 +
1.623 +void ConcurrentLocksDump::add_lock(JavaThread* thread, instanceOop o) {
1.624 + ThreadConcurrentLocks* tcl = thread_concurrent_locks(thread);
1.625 + if (tcl != NULL) {
1.626 + tcl->add_lock(o);
1.627 + return;
1.628 + }
1.629 +
1.630 + // First owned lock found for this thread
1.631 + tcl = new ThreadConcurrentLocks(thread);
1.632 + tcl->add_lock(o);
1.633 + if (_map == NULL) {
1.634 + _map = tcl;
1.635 + } else {
1.636 + _last->set_next(tcl);
1.637 + }
1.638 + _last = tcl;
1.639 +}
1.640 +
1.641 +ThreadConcurrentLocks* ConcurrentLocksDump::thread_concurrent_locks(JavaThread* thread) {
1.642 + for (ThreadConcurrentLocks* tcl = _map; tcl != NULL; tcl = tcl->next()) {
1.643 + if (tcl->java_thread() == thread) {
1.644 + return tcl;
1.645 + }
1.646 + }
1.647 + return NULL;
1.648 +}
1.649 +
1.650 +void ConcurrentLocksDump::print_locks_on(JavaThread* t, outputStream* st) {
1.651 + st->print_cr(" Locked ownable synchronizers:");
1.652 + ThreadConcurrentLocks* tcl = thread_concurrent_locks(t);
1.653 + GrowableArray<instanceOop>* locks = (tcl != NULL ? tcl->owned_locks() : NULL);
1.654 + if (locks == NULL || locks->is_empty()) {
1.655 + st->print_cr("\t- None");
1.656 + st->cr();
1.657 + return;
1.658 + }
1.659 +
1.660 + for (int i = 0; i < locks->length(); i++) {
1.661 + instanceOop obj = locks->at(i);
1.662 + instanceKlass* ik = instanceKlass::cast(obj->klass());
1.663 + st->print_cr("\t- <" INTPTR_FORMAT "> (a %s)", (address)obj, ik->external_name());
1.664 + }
1.665 + st->cr();
1.666 +}
1.667 +
1.668 +ThreadConcurrentLocks::ThreadConcurrentLocks(JavaThread* thread) {
1.669 + _thread = thread;
1.670 + _owned_locks = new (ResourceObj::C_HEAP) GrowableArray<instanceOop>(INITIAL_ARRAY_SIZE, true);
1.671 + _next = NULL;
1.672 +}
1.673 +
1.674 +ThreadConcurrentLocks::~ThreadConcurrentLocks() {
1.675 + delete _owned_locks;
1.676 +}
1.677 +
1.678 +void ThreadConcurrentLocks::add_lock(instanceOop o) {
1.679 + _owned_locks->append(o);
1.680 +}
1.681 +
1.682 +void ThreadConcurrentLocks::oops_do(OopClosure* f) {
1.683 + int length = _owned_locks->length();
1.684 + for (int i = 0; i < length; i++) {
1.685 + f->do_oop((oop*) _owned_locks->adr_at(i));
1.686 + }
1.687 +}
1.688 +
1.689 +ThreadStatistics::ThreadStatistics() {
1.690 + _contended_enter_count = 0;
1.691 + _monitor_wait_count = 0;
1.692 + _sleep_count = 0;
1.693 + _class_init_recursion_count = 0;
1.694 + _class_verify_recursion_count = 0;
1.695 + _count_pending_reset = false;
1.696 + _timer_pending_reset = false;
1.697 +}
1.698 +
1.699 +ThreadSnapshot::ThreadSnapshot(JavaThread* thread) {
1.700 + _thread = thread;
1.701 + _threadObj = thread->threadObj();
1.702 + _stack_trace = NULL;
1.703 + _concurrent_locks = NULL;
1.704 + _next = NULL;
1.705 +
1.706 + ThreadStatistics* stat = thread->get_thread_stat();
1.707 + _contended_enter_ticks = stat->contended_enter_ticks();
1.708 + _contended_enter_count = stat->contended_enter_count();
1.709 + _monitor_wait_ticks = stat->monitor_wait_ticks();
1.710 + _monitor_wait_count = stat->monitor_wait_count();
1.711 + _sleep_ticks = stat->sleep_ticks();
1.712 + _sleep_count = stat->sleep_count();
1.713 +
1.714 + _blocker_object = NULL;
1.715 + _blocker_object_owner = NULL;
1.716 +
1.717 + _thread_status = java_lang_Thread::get_thread_status(_threadObj);
1.718 + _is_ext_suspended = thread->is_being_ext_suspended();
1.719 + _is_in_native = (thread->thread_state() == _thread_in_native);
1.720 +
1.721 + if (_thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER ||
1.722 + _thread_status == java_lang_Thread::IN_OBJECT_WAIT ||
1.723 + _thread_status == java_lang_Thread::IN_OBJECT_WAIT_TIMED) {
1.724 +
1.725 + Handle obj = ThreadService::get_current_contended_monitor(thread);
1.726 + if (obj() == NULL) {
1.727 + // monitor no longer exists; thread is not blocked
1.728 + _thread_status = java_lang_Thread::RUNNABLE;
1.729 + } else {
1.730 + _blocker_object = obj();
1.731 + JavaThread* owner = ObjectSynchronizer::get_lock_owner(obj, false);
1.732 + if ((owner == NULL && _thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER)
1.733 + || (owner != NULL && owner->is_attaching())) {
1.734 + // ownership information of the monitor is not available
1.735 + // (may no longer be owned or releasing to some other thread)
1.736 + // make this thread in RUNNABLE state.
1.737 + // And when the owner thread is in attaching state, the java thread
1.738 + // is not completely initialized. For example thread name and id
1.739 + // and may not be set, so hide the attaching thread.
1.740 + _thread_status = java_lang_Thread::RUNNABLE;
1.741 + _blocker_object = NULL;
1.742 + } else if (owner != NULL) {
1.743 + _blocker_object_owner = owner->threadObj();
1.744 + }
1.745 + }
1.746 + }
1.747 +
1.748 + // Support for JSR-166 locks
1.749 + if (JDK_Version::supports_thread_park_blocker() &&
1.750 + (_thread_status == java_lang_Thread::PARKED ||
1.751 + _thread_status == java_lang_Thread::PARKED_TIMED)) {
1.752 +
1.753 + _blocker_object = thread->current_park_blocker();
1.754 + if (_blocker_object != NULL && _blocker_object->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) {
1.755 + _blocker_object_owner = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(_blocker_object);
1.756 + }
1.757 + }
1.758 +}
1.759 +
1.760 +ThreadSnapshot::~ThreadSnapshot() {
1.761 + delete _stack_trace;
1.762 + delete _concurrent_locks;
1.763 +}
1.764 +
1.765 +void ThreadSnapshot::dump_stack_at_safepoint(int max_depth, bool with_locked_monitors) {
1.766 + _stack_trace = new ThreadStackTrace(_thread, with_locked_monitors);
1.767 + _stack_trace->dump_stack_at_safepoint(max_depth);
1.768 +}
1.769 +
1.770 +
1.771 +void ThreadSnapshot::oops_do(OopClosure* f) {
1.772 + f->do_oop(&_threadObj);
1.773 + f->do_oop(&_blocker_object);
1.774 + f->do_oop(&_blocker_object_owner);
1.775 + if (_stack_trace != NULL) {
1.776 + _stack_trace->oops_do(f);
1.777 + }
1.778 + if (_concurrent_locks != NULL) {
1.779 + _concurrent_locks->oops_do(f);
1.780 + }
1.781 +}
1.782 +
1.783 +DeadlockCycle::DeadlockCycle() {
1.784 + _is_deadlock = false;
1.785 + _threads = new (ResourceObj::C_HEAP) GrowableArray<JavaThread*>(INITIAL_ARRAY_SIZE, true);
1.786 + _next = NULL;
1.787 +}
1.788 +
1.789 +DeadlockCycle::~DeadlockCycle() {
1.790 + delete _threads;
1.791 +}
1.792 +
1.793 +void DeadlockCycle::print_on(outputStream* st) const {
1.794 + st->cr();
1.795 + st->print_cr("Found one Java-level deadlock:");
1.796 + st->print("=============================");
1.797 +
1.798 + JavaThread* currentThread;
1.799 + ObjectMonitor* waitingToLockMonitor;
1.800 + oop waitingToLockBlocker;
1.801 + int len = _threads->length();
1.802 + for (int i = 0; i < len; i++) {
1.803 + currentThread = _threads->at(i);
1.804 + waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
1.805 + waitingToLockBlocker = currentThread->current_park_blocker();
1.806 + st->cr();
1.807 + st->print_cr("\"%s\":", currentThread->get_thread_name());
1.808 + const char* owner_desc = ",\n which is held by";
1.809 + if (waitingToLockMonitor != NULL) {
1.810 + st->print(" waiting to lock monitor " INTPTR_FORMAT, waitingToLockMonitor);
1.811 + oop obj = (oop)waitingToLockMonitor->object();
1.812 + if (obj != NULL) {
1.813 + st->print(" (object "INTPTR_FORMAT ", a %s)", (address)obj,
1.814 + (instanceKlass::cast(obj->klass()))->external_name());
1.815 +
1.816 + if (!currentThread->current_pending_monitor_is_from_java()) {
1.817 + owner_desc = "\n in JNI, which is held by";
1.818 + }
1.819 + } else {
1.820 + // No Java object associated - a JVMTI raw monitor
1.821 + owner_desc = " (JVMTI raw monitor),\n which is held by";
1.822 + }
1.823 + currentThread = Threads::owning_thread_from_monitor_owner(
1.824 + (address)waitingToLockMonitor->owner(), false /* no locking needed */);
1.825 + } else {
1.826 + st->print(" waiting for ownable synchronizer " INTPTR_FORMAT ", (a %s)",
1.827 + (address)waitingToLockBlocker,
1.828 + (instanceKlass::cast(waitingToLockBlocker->klass()))->external_name());
1.829 + assert(waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass()),
1.830 + "Must be an AbstractOwnableSynchronizer");
1.831 + oop ownerObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
1.832 + currentThread = java_lang_Thread::thread(ownerObj);
1.833 + }
1.834 + st->print("%s \"%s\"", owner_desc, currentThread->get_thread_name());
1.835 + }
1.836 +
1.837 + st->cr();
1.838 + st->cr();
1.839 +
1.840 + // Print stack traces
1.841 + bool oldJavaMonitorsInStackTrace = JavaMonitorsInStackTrace;
1.842 + JavaMonitorsInStackTrace = true;
1.843 + st->print_cr("Java stack information for the threads listed above:");
1.844 + st->print_cr("===================================================");
1.845 + for (int j = 0; j < len; j++) {
1.846 + currentThread = _threads->at(j);
1.847 + st->print_cr("\"%s\":", currentThread->get_thread_name());
1.848 + currentThread->print_stack_on(st);
1.849 + }
1.850 + JavaMonitorsInStackTrace = oldJavaMonitorsInStackTrace;
1.851 +}
1.852 +
1.853 +ThreadsListEnumerator::ThreadsListEnumerator(Thread* cur_thread,
1.854 + bool include_jvmti_agent_threads,
1.855 + bool include_jni_attaching_threads) {
1.856 + assert(cur_thread == Thread::current(), "Check current thread");
1.857 +
1.858 + int init_size = ThreadService::get_live_thread_count();
1.859 + _threads_array = new GrowableArray<instanceHandle>(init_size);
1.860 +
1.861 + MutexLockerEx ml(Threads_lock);
1.862 +
1.863 + for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
1.864 + // skips JavaThreads in the process of exiting
1.865 + // and also skips VM internal JavaThreads
1.866 + // Threads in _thread_new or _thread_new_trans state are included.
1.867 + // i.e. threads have been started but not yet running.
1.868 + if (jt->threadObj() == NULL ||
1.869 + jt->is_exiting() ||
1.870 + !java_lang_Thread::is_alive(jt->threadObj()) ||
1.871 + jt->is_hidden_from_external_view()) {
1.872 + continue;
1.873 + }
1.874 +
1.875 + // skip agent threads
1.876 + if (!include_jvmti_agent_threads && jt->is_jvmti_agent_thread()) {
1.877 + continue;
1.878 + }
1.879 +
1.880 + // skip jni threads in the process of attaching
1.881 + if (!include_jni_attaching_threads && jt->is_attaching()) {
1.882 + continue;
1.883 + }
1.884 +
1.885 + instanceHandle h(cur_thread, (instanceOop) jt->threadObj());
1.886 + _threads_array->append(h);
1.887 + }
1.888 +}
