1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/services/threadService.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,976 @@
1.4 +/*
1.5 + * Copyright (c) 2003, 2014, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "classfile/systemDictionary.hpp"
1.30 +#include "memory/allocation.hpp"
1.31 +#include "memory/heapInspection.hpp"
1.32 +#include "memory/oopFactory.hpp"
1.33 +#include "oops/instanceKlass.hpp"
1.34 +#include "oops/oop.inline.hpp"
1.35 +#include "runtime/handles.inline.hpp"
1.36 +#include "runtime/init.hpp"
1.37 +#include "runtime/thread.hpp"
1.38 +#include "runtime/vframe.hpp"
1.39 +#include "runtime/vmThread.hpp"
1.40 +#include "runtime/vm_operations.hpp"
1.41 +#include "services/threadService.hpp"
1.42 +
1.43 +PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
1.44 +
1.45 +// TODO: we need to define a naming convention for perf counters
1.46 +// to distinguish counters for:
1.47 +// - standard JSR174 use
1.48 +// - Hotspot extension (public and committed)
1.49 +// - Hotspot extension (private/internal and uncommitted)
1.50 +
1.51 +// Default is disabled.
1.52 +bool ThreadService::_thread_monitoring_contention_enabled = false;
1.53 +bool ThreadService::_thread_cpu_time_enabled = false;
1.54 +bool ThreadService::_thread_allocated_memory_enabled = false;
1.55 +
1.56 +PerfCounter* ThreadService::_total_threads_count = NULL;
1.57 +PerfVariable* ThreadService::_live_threads_count = NULL;
1.58 +PerfVariable* ThreadService::_peak_threads_count = NULL;
1.59 +PerfVariable* ThreadService::_daemon_threads_count = NULL;
1.60 +volatile int ThreadService::_exiting_threads_count = 0;
1.61 +volatile int ThreadService::_exiting_daemon_threads_count = 0;
1.62 +
1.63 +ThreadDumpResult* ThreadService::_threaddump_list = NULL;
1.64 +
1.65 +static const int INITIAL_ARRAY_SIZE = 10;
1.66 +
1.67 +void ThreadService::init() {
1.68 + EXCEPTION_MARK;
1.69 +
1.70 + // These counters are for java.lang.management API support.
1.71 + // They are created even if -XX:-UsePerfData is set and in
1.72 + // that case, they will be allocated on C heap.
1.73 +
1.74 + _total_threads_count =
1.75 + PerfDataManager::create_counter(JAVA_THREADS, "started",
1.76 + PerfData::U_Events, CHECK);
1.77 +
1.78 + _live_threads_count =
1.79 + PerfDataManager::create_variable(JAVA_THREADS, "live",
1.80 + PerfData::U_None, CHECK);
1.81 +
1.82 + _peak_threads_count =
1.83 + PerfDataManager::create_variable(JAVA_THREADS, "livePeak",
1.84 + PerfData::U_None, CHECK);
1.85 +
1.86 + _daemon_threads_count =
1.87 + PerfDataManager::create_variable(JAVA_THREADS, "daemon",
1.88 + PerfData::U_None, CHECK);
1.89 +
1.90 + if (os::is_thread_cpu_time_supported()) {
1.91 + _thread_cpu_time_enabled = true;
1.92 + }
1.93 +
1.94 + _thread_allocated_memory_enabled = true; // Always on, so enable it
1.95 +}
1.96 +
1.97 +void ThreadService::reset_peak_thread_count() {
1.98 + // Acquire the lock to update the peak thread count
1.99 + // to synchronize with thread addition and removal.
1.100 + MutexLockerEx mu(Threads_lock);
1.101 + _peak_threads_count->set_value(get_live_thread_count());
1.102 +}
1.103 +
1.104 +void ThreadService::add_thread(JavaThread* thread, bool daemon) {
1.105 + // Do not count VM internal or JVMTI agent threads
1.106 + if (thread->is_hidden_from_external_view() ||
1.107 + thread->is_jvmti_agent_thread()) {
1.108 + return;
1.109 + }
1.110 +
1.111 + _total_threads_count->inc();
1.112 + _live_threads_count->inc();
1.113 +
1.114 + if (_live_threads_count->get_value() > _peak_threads_count->get_value()) {
1.115 + _peak_threads_count->set_value(_live_threads_count->get_value());
1.116 + }
1.117 +
1.118 + if (daemon) {
1.119 + _daemon_threads_count->inc();
1.120 + }
1.121 +}
1.122 +
1.123 +void ThreadService::remove_thread(JavaThread* thread, bool daemon) {
1.124 + Atomic::dec((jint*) &_exiting_threads_count);
1.125 +
1.126 + if (thread->is_hidden_from_external_view() ||
1.127 + thread->is_jvmti_agent_thread()) {
1.128 + return;
1.129 + }
1.130 +
1.131 + _live_threads_count->set_value(_live_threads_count->get_value() - 1);
1.132 +
1.133 + if (daemon) {
1.134 + _daemon_threads_count->set_value(_daemon_threads_count->get_value() - 1);
1.135 + Atomic::dec((jint*) &_exiting_daemon_threads_count);
1.136 + }
1.137 +}
1.138 +
1.139 +void ThreadService::current_thread_exiting(JavaThread* jt) {
1.140 + assert(jt == JavaThread::current(), "Called by current thread");
1.141 + Atomic::inc((jint*) &_exiting_threads_count);
1.142 +
1.143 + oop threadObj = jt->threadObj();
1.144 + if (threadObj != NULL && java_lang_Thread::is_daemon(threadObj)) {
1.145 + Atomic::inc((jint*) &_exiting_daemon_threads_count);
1.146 + }
1.147 +}
1.148 +
1.149 +// FIXME: JVMTI should call this function
1.150 +Handle ThreadService::get_current_contended_monitor(JavaThread* thread) {
1.151 + assert(thread != NULL, "should be non-NULL");
1.152 + assert(Threads_lock->owned_by_self(), "must grab Threads_lock or be at safepoint");
1.153 +
1.154 + ObjectMonitor *wait_obj = thread->current_waiting_monitor();
1.155 +
1.156 + oop obj = NULL;
1.157 + if (wait_obj != NULL) {
1.158 + // thread is doing an Object.wait() call
1.159 + obj = (oop) wait_obj->object();
1.160 + assert(obj != NULL, "Object.wait() should have an object");
1.161 + } else {
1.162 + ObjectMonitor *enter_obj = thread->current_pending_monitor();
1.163 + if (enter_obj != NULL) {
1.164 + // thread is trying to enter() or raw_enter() an ObjectMonitor.
1.165 + obj = (oop) enter_obj->object();
1.166 + }
1.167 + // If obj == NULL, then ObjectMonitor is raw which doesn't count.
1.168 + }
1.169 +
1.170 + Handle h(obj);
1.171 + return h;
1.172 +}
1.173 +
1.174 +bool ThreadService::set_thread_monitoring_contention(bool flag) {
1.175 + MutexLocker m(Management_lock);
1.176 +
1.177 + bool prev = _thread_monitoring_contention_enabled;
1.178 + _thread_monitoring_contention_enabled = flag;
1.179 +
1.180 + return prev;
1.181 +}
1.182 +
1.183 +bool ThreadService::set_thread_cpu_time_enabled(bool flag) {
1.184 + MutexLocker m(Management_lock);
1.185 +
1.186 + bool prev = _thread_cpu_time_enabled;
1.187 + _thread_cpu_time_enabled = flag;
1.188 +
1.189 + return prev;
1.190 +}
1.191 +
1.192 +bool ThreadService::set_thread_allocated_memory_enabled(bool flag) {
1.193 + MutexLocker m(Management_lock);
1.194 +
1.195 + bool prev = _thread_allocated_memory_enabled;
1.196 + _thread_allocated_memory_enabled = flag;
1.197 +
1.198 + return prev;
1.199 +}
1.200 +
1.201 +// GC support
1.202 +void ThreadService::oops_do(OopClosure* f) {
1.203 + for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) {
1.204 + dump->oops_do(f);
1.205 + }
1.206 +}
1.207 +
1.208 +void ThreadService::metadata_do(void f(Metadata*)) {
1.209 + for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) {
1.210 + dump->metadata_do(f);
1.211 + }
1.212 +}
1.213 +
1.214 +void ThreadService::add_thread_dump(ThreadDumpResult* dump) {
1.215 + MutexLocker ml(Management_lock);
1.216 + if (_threaddump_list == NULL) {
1.217 + _threaddump_list = dump;
1.218 + } else {
1.219 + dump->set_next(_threaddump_list);
1.220 + _threaddump_list = dump;
1.221 + }
1.222 +}
1.223 +
1.224 +void ThreadService::remove_thread_dump(ThreadDumpResult* dump) {
1.225 + MutexLocker ml(Management_lock);
1.226 +
1.227 + ThreadDumpResult* prev = NULL;
1.228 + bool found = false;
1.229 + for (ThreadDumpResult* d = _threaddump_list; d != NULL; prev = d, d = d->next()) {
1.230 + if (d == dump) {
1.231 + if (prev == NULL) {
1.232 + _threaddump_list = dump->next();
1.233 + } else {
1.234 + prev->set_next(dump->next());
1.235 + }
1.236 + found = true;
1.237 + break;
1.238 + }
1.239 + }
1.240 + assert(found, "The threaddump result to be removed must exist.");
1.241 +}
1.242 +
1.243 +// Dump stack trace of threads specified in the given threads array.
1.244 +// Returns StackTraceElement[][] each element is the stack trace of a thread in
1.245 +// the corresponding entry in the given threads array
1.246 +Handle ThreadService::dump_stack_traces(GrowableArray<instanceHandle>* threads,
1.247 + int num_threads,
1.248 + TRAPS) {
1.249 + assert(num_threads > 0, "just checking");
1.250 +
1.251 + ThreadDumpResult dump_result;
1.252 + VM_ThreadDump op(&dump_result,
1.253 + threads,
1.254 + num_threads,
1.255 + -1, /* entire stack */
1.256 + false, /* with locked monitors */
1.257 + false /* with locked synchronizers */);
1.258 + VMThread::execute(&op);
1.259 +
1.260 + // Allocate the resulting StackTraceElement[][] object
1.261 +
1.262 + ResourceMark rm(THREAD);
1.263 + Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_StackTraceElement_array(), true, CHECK_NH);
1.264 + ObjArrayKlass* ik = ObjArrayKlass::cast(k);
1.265 + objArrayOop r = oopFactory::new_objArray(ik, num_threads, CHECK_NH);
1.266 + objArrayHandle result_obj(THREAD, r);
1.267 +
1.268 + int num_snapshots = dump_result.num_snapshots();
1.269 + assert(num_snapshots == num_threads, "Must have num_threads thread snapshots");
1.270 + int i = 0;
1.271 + for (ThreadSnapshot* ts = dump_result.snapshots(); ts != NULL; i++, ts = ts->next()) {
1.272 + ThreadStackTrace* stacktrace = ts->get_stack_trace();
1.273 + if (stacktrace == NULL) {
1.274 + // No stack trace
1.275 + result_obj->obj_at_put(i, NULL);
1.276 + } else {
1.277 + // Construct an array of java/lang/StackTraceElement object
1.278 + Handle backtrace_h = stacktrace->allocate_fill_stack_trace_element_array(CHECK_NH);
1.279 + result_obj->obj_at_put(i, backtrace_h());
1.280 + }
1.281 + }
1.282 +
1.283 + return result_obj;
1.284 +}
1.285 +
1.286 +void ThreadService::reset_contention_count_stat(JavaThread* thread) {
1.287 + ThreadStatistics* stat = thread->get_thread_stat();
1.288 + if (stat != NULL) {
1.289 + stat->reset_count_stat();
1.290 + }
1.291 +}
1.292 +
1.293 +void ThreadService::reset_contention_time_stat(JavaThread* thread) {
1.294 + ThreadStatistics* stat = thread->get_thread_stat();
1.295 + if (stat != NULL) {
1.296 + stat->reset_time_stat();
1.297 + }
1.298 +}
1.299 +
1.300 +// Find deadlocks involving object monitors and concurrent locks if concurrent_locks is true
1.301 +DeadlockCycle* ThreadService::find_deadlocks_at_safepoint(bool concurrent_locks) {
1.302 + // This code was modified from the original Threads::find_deadlocks code.
1.303 + int globalDfn = 0, thisDfn;
1.304 + ObjectMonitor* waitingToLockMonitor = NULL;
1.305 + oop waitingToLockBlocker = NULL;
1.306 + bool blocked_on_monitor = false;
1.307 + JavaThread *currentThread, *previousThread;
1.308 + int num_deadlocks = 0;
1.309 +
1.310 + for (JavaThread* p = Threads::first(); p != NULL; p = p->next()) {
1.311 + // Initialize the depth-first-number
1.312 + p->set_depth_first_number(-1);
1.313 + }
1.314 +
1.315 + DeadlockCycle* deadlocks = NULL;
1.316 + DeadlockCycle* last = NULL;
1.317 + DeadlockCycle* cycle = new DeadlockCycle();
1.318 + for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
1.319 + if (jt->depth_first_number() >= 0) {
1.320 + // this thread was already visited
1.321 + continue;
1.322 + }
1.323 +
1.324 + thisDfn = globalDfn;
1.325 + jt->set_depth_first_number(globalDfn++);
1.326 + previousThread = jt;
1.327 + currentThread = jt;
1.328 +
1.329 + cycle->reset();
1.330 +
1.331 + // When there is a deadlock, all the monitors involved in the dependency
1.332 + // cycle must be contended and heavyweight. So we only care about the
1.333 + // heavyweight monitor a thread is waiting to lock.
1.334 + waitingToLockMonitor = (ObjectMonitor*)jt->current_pending_monitor();
1.335 + if (concurrent_locks) {
1.336 + waitingToLockBlocker = jt->current_park_blocker();
1.337 + }
1.338 + while (waitingToLockMonitor != NULL || waitingToLockBlocker != NULL) {
1.339 + cycle->add_thread(currentThread);
1.340 + if (waitingToLockMonitor != NULL) {
1.341 + address currentOwner = (address)waitingToLockMonitor->owner();
1.342 + if (currentOwner != NULL) {
1.343 + currentThread = Threads::owning_thread_from_monitor_owner(
1.344 + currentOwner,
1.345 + false /* no locking needed */);
1.346 + if (currentThread == NULL) {
1.347 + // This function is called at a safepoint so the JavaThread
1.348 + // that owns waitingToLockMonitor should be findable, but
1.349 + // if it is not findable, then the previous currentThread is
1.350 + // blocked permanently. We record this as a deadlock.
1.351 + num_deadlocks++;
1.352 +
1.353 + cycle->set_deadlock(true);
1.354 +
1.355 + // add this cycle to the deadlocks list
1.356 + if (deadlocks == NULL) {
1.357 + deadlocks = cycle;
1.358 + } else {
1.359 + last->set_next(cycle);
1.360 + }
1.361 + last = cycle;
1.362 + cycle = new DeadlockCycle();
1.363 + break;
1.364 + }
1.365 + }
1.366 + } else {
1.367 + if (concurrent_locks) {
1.368 + if (waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) {
1.369 + oop threadObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
1.370 + currentThread = threadObj != NULL ? java_lang_Thread::thread(threadObj) : NULL;
1.371 + } else {
1.372 + currentThread = NULL;
1.373 + }
1.374 + }
1.375 + }
1.376 +
1.377 + if (currentThread == NULL) {
1.378 + // No dependency on another thread
1.379 + break;
1.380 + }
1.381 + if (currentThread->depth_first_number() < 0) {
1.382 + // First visit to this thread
1.383 + currentThread->set_depth_first_number(globalDfn++);
1.384 + } else if (currentThread->depth_first_number() < thisDfn) {
1.385 + // Thread already visited, and not on a (new) cycle
1.386 + break;
1.387 + } else if (currentThread == previousThread) {
1.388 + // Self-loop, ignore
1.389 + break;
1.390 + } else {
1.391 + // We have a (new) cycle
1.392 + num_deadlocks++;
1.393 +
1.394 + cycle->set_deadlock(true);
1.395 +
1.396 + // add this cycle to the deadlocks list
1.397 + if (deadlocks == NULL) {
1.398 + deadlocks = cycle;
1.399 + } else {
1.400 + last->set_next(cycle);
1.401 + }
1.402 + last = cycle;
1.403 + cycle = new DeadlockCycle();
1.404 + break;
1.405 + }
1.406 + previousThread = currentThread;
1.407 + waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
1.408 + if (concurrent_locks) {
1.409 + waitingToLockBlocker = currentThread->current_park_blocker();
1.410 + }
1.411 + }
1.412 +
1.413 + }
1.414 + delete cycle;
1.415 + return deadlocks;
1.416 +}
1.417 +
1.418 +ThreadDumpResult::ThreadDumpResult() : _num_threads(0), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) {
1.419 +
1.420 + // Create a new ThreadDumpResult object and append to the list.
1.421 + // If GC happens before this function returns, Method*
1.422 + // in the stack trace will be visited.
1.423 + ThreadService::add_thread_dump(this);
1.424 +}
1.425 +
1.426 +ThreadDumpResult::ThreadDumpResult(int num_threads) : _num_threads(num_threads), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) {
1.427 + // Create a new ThreadDumpResult object and append to the list.
1.428 + // If GC happens before this function returns, oops
1.429 + // will be visited.
1.430 + ThreadService::add_thread_dump(this);
1.431 +}
1.432 +
1.433 +ThreadDumpResult::~ThreadDumpResult() {
1.434 + ThreadService::remove_thread_dump(this);
1.435 +
1.436 + // free all the ThreadSnapshot objects created during
1.437 + // the VM_ThreadDump operation
1.438 + ThreadSnapshot* ts = _snapshots;
1.439 + while (ts != NULL) {
1.440 + ThreadSnapshot* p = ts;
1.441 + ts = ts->next();
1.442 + delete p;
1.443 + }
1.444 +}
1.445 +
1.446 +
1.447 +void ThreadDumpResult::add_thread_snapshot(ThreadSnapshot* ts) {
1.448 + assert(_num_threads == 0 || _num_snapshots < _num_threads,
1.449 + "_num_snapshots must be less than _num_threads");
1.450 + _num_snapshots++;
1.451 + if (_snapshots == NULL) {
1.452 + _snapshots = ts;
1.453 + } else {
1.454 + _last->set_next(ts);
1.455 + }
1.456 + _last = ts;
1.457 +}
1.458 +
1.459 +void ThreadDumpResult::oops_do(OopClosure* f) {
1.460 + for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) {
1.461 + ts->oops_do(f);
1.462 + }
1.463 +}
1.464 +
1.465 +void ThreadDumpResult::metadata_do(void f(Metadata*)) {
1.466 + for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) {
1.467 + ts->metadata_do(f);
1.468 + }
1.469 +}
1.470 +
1.471 +StackFrameInfo::StackFrameInfo(javaVFrame* jvf, bool with_lock_info) {
1.472 + _method = jvf->method();
1.473 + _bci = jvf->bci();
1.474 + _class_holder = _method->method_holder()->klass_holder();
1.475 + _locked_monitors = NULL;
1.476 + if (with_lock_info) {
1.477 + ResourceMark rm;
1.478 + GrowableArray<MonitorInfo*>* list = jvf->locked_monitors();
1.479 + int length = list->length();
1.480 + if (length > 0) {
1.481 + _locked_monitors = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(length, true);
1.482 + for (int i = 0; i < length; i++) {
1.483 + MonitorInfo* monitor = list->at(i);
1.484 + assert(monitor->owner(), "This monitor must have an owning object");
1.485 + _locked_monitors->append(monitor->owner());
1.486 + }
1.487 + }
1.488 + }
1.489 +}
1.490 +
1.491 +void StackFrameInfo::oops_do(OopClosure* f) {
1.492 + if (_locked_monitors != NULL) {
1.493 + int length = _locked_monitors->length();
1.494 + for (int i = 0; i < length; i++) {
1.495 + f->do_oop((oop*) _locked_monitors->adr_at(i));
1.496 + }
1.497 + }
1.498 + f->do_oop(&_class_holder);
1.499 +}
1.500 +
1.501 +void StackFrameInfo::metadata_do(void f(Metadata*)) {
1.502 + f(_method);
1.503 +}
1.504 +
1.505 +void StackFrameInfo::print_on(outputStream* st) const {
1.506 + ResourceMark rm;
1.507 + java_lang_Throwable::print_stack_element(st, method(), bci());
1.508 + int len = (_locked_monitors != NULL ? _locked_monitors->length() : 0);
1.509 + for (int i = 0; i < len; i++) {
1.510 + oop o = _locked_monitors->at(i);
1.511 + InstanceKlass* ik = InstanceKlass::cast(o->klass());
1.512 + st->print_cr("\t- locked <" INTPTR_FORMAT "> (a %s)", (address)o, ik->external_name());
1.513 + }
1.514 +
1.515 +}
1.516 +
1.517 +// Iterate through monitor cache to find JNI locked monitors
1.518 +class InflatedMonitorsClosure: public MonitorClosure {
1.519 +private:
1.520 + ThreadStackTrace* _stack_trace;
1.521 + Thread* _thread;
1.522 +public:
1.523 + InflatedMonitorsClosure(Thread* t, ThreadStackTrace* st) {
1.524 + _thread = t;
1.525 + _stack_trace = st;
1.526 + }
1.527 + void do_monitor(ObjectMonitor* mid) {
1.528 + if (mid->owner() == _thread) {
1.529 + oop object = (oop) mid->object();
1.530 + if (!_stack_trace->is_owned_monitor_on_stack(object)) {
1.531 + _stack_trace->add_jni_locked_monitor(object);
1.532 + }
1.533 + }
1.534 + }
1.535 +};
1.536 +
1.537 +ThreadStackTrace::ThreadStackTrace(JavaThread* t, bool with_locked_monitors) {
1.538 + _thread = t;
1.539 + _frames = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<StackFrameInfo*>(INITIAL_ARRAY_SIZE, true);
1.540 + _depth = 0;
1.541 + _with_locked_monitors = with_locked_monitors;
1.542 + if (_with_locked_monitors) {
1.543 + _jni_locked_monitors = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(INITIAL_ARRAY_SIZE, true);
1.544 + } else {
1.545 + _jni_locked_monitors = NULL;
1.546 + }
1.547 +}
1.548 +
1.549 +ThreadStackTrace::~ThreadStackTrace() {
1.550 + for (int i = 0; i < _frames->length(); i++) {
1.551 + delete _frames->at(i);
1.552 + }
1.553 + delete _frames;
1.554 + if (_jni_locked_monitors != NULL) {
1.555 + delete _jni_locked_monitors;
1.556 + }
1.557 +}
1.558 +
1.559 +void ThreadStackTrace::dump_stack_at_safepoint(int maxDepth) {
1.560 + assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1.561 +
1.562 + if (_thread->has_last_Java_frame()) {
1.563 + RegisterMap reg_map(_thread);
1.564 + vframe* start_vf = _thread->last_java_vframe(®_map);
1.565 + int count = 0;
1.566 + for (vframe* f = start_vf; f; f = f->sender() ) {
1.567 + if (f->is_java_frame()) {
1.568 + javaVFrame* jvf = javaVFrame::cast(f);
1.569 + add_stack_frame(jvf);
1.570 + count++;
1.571 + } else {
1.572 + // Ignore non-Java frames
1.573 + }
1.574 + if (maxDepth > 0 && count == maxDepth) {
1.575 + // Skip frames if more than maxDepth
1.576 + break;
1.577 + }
1.578 + }
1.579 + }
1.580 +
1.581 + if (_with_locked_monitors) {
1.582 + // Iterate inflated monitors and find monitors locked by this thread
1.583 + // not found in the stack
1.584 + InflatedMonitorsClosure imc(_thread, this);
1.585 + ObjectSynchronizer::monitors_iterate(&imc);
1.586 + }
1.587 +}
1.588 +
1.589 +
1.590 +bool ThreadStackTrace::is_owned_monitor_on_stack(oop object) {
1.591 + assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1.592 +
1.593 + bool found = false;
1.594 + int num_frames = get_stack_depth();
1.595 + for (int depth = 0; depth < num_frames; depth++) {
1.596 + StackFrameInfo* frame = stack_frame_at(depth);
1.597 + int len = frame->num_locked_monitors();
1.598 + GrowableArray<oop>* locked_monitors = frame->locked_monitors();
1.599 + for (int j = 0; j < len; j++) {
1.600 + oop monitor = locked_monitors->at(j);
1.601 + assert(monitor != NULL && monitor->is_instance(), "must be a Java object");
1.602 + if (monitor == object) {
1.603 + found = true;
1.604 + break;
1.605 + }
1.606 + }
1.607 + }
1.608 + return found;
1.609 +}
1.610 +
1.611 +Handle ThreadStackTrace::allocate_fill_stack_trace_element_array(TRAPS) {
1.612 + Klass* k = SystemDictionary::StackTraceElement_klass();
1.613 + assert(k != NULL, "must be loaded in 1.4+");
1.614 + instanceKlassHandle ik(THREAD, k);
1.615 +
1.616 + // Allocate an array of java/lang/StackTraceElement object
1.617 + objArrayOop ste = oopFactory::new_objArray(ik(), _depth, CHECK_NH);
1.618 + objArrayHandle backtrace(THREAD, ste);
1.619 + for (int j = 0; j < _depth; j++) {
1.620 + StackFrameInfo* frame = _frames->at(j);
1.621 + methodHandle mh(THREAD, frame->method());
1.622 + oop element = java_lang_StackTraceElement::create(mh, frame->bci(), CHECK_NH);
1.623 + backtrace->obj_at_put(j, element);
1.624 + }
1.625 + return backtrace;
1.626 +}
1.627 +
1.628 +void ThreadStackTrace::add_stack_frame(javaVFrame* jvf) {
1.629 + StackFrameInfo* frame = new StackFrameInfo(jvf, _with_locked_monitors);
1.630 + _frames->append(frame);
1.631 + _depth++;
1.632 +}
1.633 +
1.634 +void ThreadStackTrace::oops_do(OopClosure* f) {
1.635 + int length = _frames->length();
1.636 + for (int i = 0; i < length; i++) {
1.637 + _frames->at(i)->oops_do(f);
1.638 + }
1.639 +
1.640 + length = (_jni_locked_monitors != NULL ? _jni_locked_monitors->length() : 0);
1.641 + for (int j = 0; j < length; j++) {
1.642 + f->do_oop((oop*) _jni_locked_monitors->adr_at(j));
1.643 + }
1.644 +}
1.645 +
1.646 +void ThreadStackTrace::metadata_do(void f(Metadata*)) {
1.647 + int length = _frames->length();
1.648 + for (int i = 0; i < length; i++) {
1.649 + _frames->at(i)->metadata_do(f);
1.650 + }
1.651 +}
1.652 +
1.653 +
1.654 +ConcurrentLocksDump::~ConcurrentLocksDump() {
1.655 + if (_retain_map_on_free) {
1.656 + return;
1.657 + }
1.658 +
1.659 + for (ThreadConcurrentLocks* t = _map; t != NULL;) {
1.660 + ThreadConcurrentLocks* tcl = t;
1.661 + t = t->next();
1.662 + delete tcl;
1.663 + }
1.664 +}
1.665 +
1.666 +void ConcurrentLocksDump::dump_at_safepoint() {
1.667 + // dump all locked concurrent locks
1.668 + assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
1.669 +
1.670 + if (JDK_Version::is_gte_jdk16x_version()) {
1.671 + ResourceMark rm;
1.672 +
1.673 + GrowableArray<oop>* aos_objects = new GrowableArray<oop>(INITIAL_ARRAY_SIZE);
1.674 +
1.675 + // Find all instances of AbstractOwnableSynchronizer
1.676 + HeapInspection::find_instances_at_safepoint(SystemDictionary::abstract_ownable_synchronizer_klass(),
1.677 + aos_objects);
1.678 + // Build a map of thread to its owned AQS locks
1.679 + build_map(aos_objects);
1.680 + }
1.681 +}
1.682 +
1.683 +
1.684 +// build a map of JavaThread to all its owned AbstractOwnableSynchronizer
1.685 +void ConcurrentLocksDump::build_map(GrowableArray<oop>* aos_objects) {
1.686 + int length = aos_objects->length();
1.687 + for (int i = 0; i < length; i++) {
1.688 + oop o = aos_objects->at(i);
1.689 + oop owner_thread_obj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(o);
1.690 + if (owner_thread_obj != NULL) {
1.691 + JavaThread* thread = java_lang_Thread::thread(owner_thread_obj);
1.692 + assert(o->is_instance(), "Must be an instanceOop");
1.693 + add_lock(thread, (instanceOop) o);
1.694 + }
1.695 + }
1.696 +}
1.697 +
1.698 +void ConcurrentLocksDump::add_lock(JavaThread* thread, instanceOop o) {
1.699 + ThreadConcurrentLocks* tcl = thread_concurrent_locks(thread);
1.700 + if (tcl != NULL) {
1.701 + tcl->add_lock(o);
1.702 + return;
1.703 + }
1.704 +
1.705 + // First owned lock found for this thread
1.706 + tcl = new ThreadConcurrentLocks(thread);
1.707 + tcl->add_lock(o);
1.708 + if (_map == NULL) {
1.709 + _map = tcl;
1.710 + } else {
1.711 + _last->set_next(tcl);
1.712 + }
1.713 + _last = tcl;
1.714 +}
1.715 +
1.716 +ThreadConcurrentLocks* ConcurrentLocksDump::thread_concurrent_locks(JavaThread* thread) {
1.717 + for (ThreadConcurrentLocks* tcl = _map; tcl != NULL; tcl = tcl->next()) {
1.718 + if (tcl->java_thread() == thread) {
1.719 + return tcl;
1.720 + }
1.721 + }
1.722 + return NULL;
1.723 +}
1.724 +
1.725 +void ConcurrentLocksDump::print_locks_on(JavaThread* t, outputStream* st) {
1.726 + st->print_cr(" Locked ownable synchronizers:");
1.727 + ThreadConcurrentLocks* tcl = thread_concurrent_locks(t);
1.728 + GrowableArray<instanceOop>* locks = (tcl != NULL ? tcl->owned_locks() : NULL);
1.729 + if (locks == NULL || locks->is_empty()) {
1.730 + st->print_cr("\t- None");
1.731 + st->cr();
1.732 + return;
1.733 + }
1.734 +
1.735 + for (int i = 0; i < locks->length(); i++) {
1.736 + instanceOop obj = locks->at(i);
1.737 + InstanceKlass* ik = InstanceKlass::cast(obj->klass());
1.738 + st->print_cr("\t- <" INTPTR_FORMAT "> (a %s)", (address)obj, ik->external_name());
1.739 + }
1.740 + st->cr();
1.741 +}
1.742 +
1.743 +ThreadConcurrentLocks::ThreadConcurrentLocks(JavaThread* thread) {
1.744 + _thread = thread;
1.745 + _owned_locks = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<instanceOop>(INITIAL_ARRAY_SIZE, true);
1.746 + _next = NULL;
1.747 +}
1.748 +
1.749 +ThreadConcurrentLocks::~ThreadConcurrentLocks() {
1.750 + delete _owned_locks;
1.751 +}
1.752 +
1.753 +void ThreadConcurrentLocks::add_lock(instanceOop o) {
1.754 + _owned_locks->append(o);
1.755 +}
1.756 +
1.757 +void ThreadConcurrentLocks::oops_do(OopClosure* f) {
1.758 + int length = _owned_locks->length();
1.759 + for (int i = 0; i < length; i++) {
1.760 + f->do_oop((oop*) _owned_locks->adr_at(i));
1.761 + }
1.762 +}
1.763 +
1.764 +ThreadStatistics::ThreadStatistics() {
1.765 + _contended_enter_count = 0;
1.766 + _monitor_wait_count = 0;
1.767 + _sleep_count = 0;
1.768 + _count_pending_reset = false;
1.769 + _timer_pending_reset = false;
1.770 + memset((void*) _perf_recursion_counts, 0, sizeof(_perf_recursion_counts));
1.771 +}
1.772 +
1.773 +ThreadSnapshot::ThreadSnapshot(JavaThread* thread) {
1.774 + _thread = thread;
1.775 + _threadObj = thread->threadObj();
1.776 + _stack_trace = NULL;
1.777 + _concurrent_locks = NULL;
1.778 + _next = NULL;
1.779 +
1.780 + ThreadStatistics* stat = thread->get_thread_stat();
1.781 + _contended_enter_ticks = stat->contended_enter_ticks();
1.782 + _contended_enter_count = stat->contended_enter_count();
1.783 + _monitor_wait_ticks = stat->monitor_wait_ticks();
1.784 + _monitor_wait_count = stat->monitor_wait_count();
1.785 + _sleep_ticks = stat->sleep_ticks();
1.786 + _sleep_count = stat->sleep_count();
1.787 +
1.788 + _blocker_object = NULL;
1.789 + _blocker_object_owner = NULL;
1.790 +
1.791 + _thread_status = java_lang_Thread::get_thread_status(_threadObj);
1.792 + _is_ext_suspended = thread->is_being_ext_suspended();
1.793 + _is_in_native = (thread->thread_state() == _thread_in_native);
1.794 +
1.795 + if (_thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER ||
1.796 + _thread_status == java_lang_Thread::IN_OBJECT_WAIT ||
1.797 + _thread_status == java_lang_Thread::IN_OBJECT_WAIT_TIMED) {
1.798 +
1.799 + Handle obj = ThreadService::get_current_contended_monitor(thread);
1.800 + if (obj() == NULL) {
1.801 + // monitor no longer exists; thread is not blocked
1.802 + _thread_status = java_lang_Thread::RUNNABLE;
1.803 + } else {
1.804 + _blocker_object = obj();
1.805 + JavaThread* owner = ObjectSynchronizer::get_lock_owner(obj, false);
1.806 + if ((owner == NULL && _thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER)
1.807 + || (owner != NULL && owner->is_attaching_via_jni())) {
1.808 + // ownership information of the monitor is not available
1.809 + // (may no longer be owned or releasing to some other thread)
1.810 + // make this thread in RUNNABLE state.
1.811 + // And when the owner thread is in attaching state, the java thread
1.812 + // is not completely initialized. For example thread name and id
1.813 + // and may not be set, so hide the attaching thread.
1.814 + _thread_status = java_lang_Thread::RUNNABLE;
1.815 + _blocker_object = NULL;
1.816 + } else if (owner != NULL) {
1.817 + _blocker_object_owner = owner->threadObj();
1.818 + }
1.819 + }
1.820 + }
1.821 +
1.822 + // Support for JSR-166 locks
1.823 + if (JDK_Version::current().supports_thread_park_blocker() &&
1.824 + (_thread_status == java_lang_Thread::PARKED ||
1.825 + _thread_status == java_lang_Thread::PARKED_TIMED)) {
1.826 +
1.827 + _blocker_object = thread->current_park_blocker();
1.828 + if (_blocker_object != NULL && _blocker_object->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) {
1.829 + _blocker_object_owner = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(_blocker_object);
1.830 + }
1.831 + }
1.832 +}
1.833 +
1.834 +ThreadSnapshot::~ThreadSnapshot() {
1.835 + delete _stack_trace;
1.836 + delete _concurrent_locks;
1.837 +}
1.838 +
1.839 +void ThreadSnapshot::dump_stack_at_safepoint(int max_depth, bool with_locked_monitors) {
1.840 + _stack_trace = new ThreadStackTrace(_thread, with_locked_monitors);
1.841 + _stack_trace->dump_stack_at_safepoint(max_depth);
1.842 +}
1.843 +
1.844 +
1.845 +void ThreadSnapshot::oops_do(OopClosure* f) {
1.846 + f->do_oop(&_threadObj);
1.847 + f->do_oop(&_blocker_object);
1.848 + f->do_oop(&_blocker_object_owner);
1.849 + if (_stack_trace != NULL) {
1.850 + _stack_trace->oops_do(f);
1.851 + }
1.852 + if (_concurrent_locks != NULL) {
1.853 + _concurrent_locks->oops_do(f);
1.854 + }
1.855 +}
1.856 +
1.857 +void ThreadSnapshot::metadata_do(void f(Metadata*)) {
1.858 + if (_stack_trace != NULL) {
1.859 + _stack_trace->metadata_do(f);
1.860 + }
1.861 +}
1.862 +
1.863 +
1.864 +DeadlockCycle::DeadlockCycle() {
1.865 + _is_deadlock = false;
1.866 + _threads = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<JavaThread*>(INITIAL_ARRAY_SIZE, true);
1.867 + _next = NULL;
1.868 +}
1.869 +
1.870 +DeadlockCycle::~DeadlockCycle() {
1.871 + delete _threads;
1.872 +}
1.873 +
1.874 +void DeadlockCycle::print_on(outputStream* st) const {
1.875 + st->cr();
1.876 + st->print_cr("Found one Java-level deadlock:");
1.877 + st->print("=============================");
1.878 +
1.879 + JavaThread* currentThread;
1.880 + ObjectMonitor* waitingToLockMonitor;
1.881 + oop waitingToLockBlocker;
1.882 + int len = _threads->length();
1.883 + for (int i = 0; i < len; i++) {
1.884 + currentThread = _threads->at(i);
1.885 + waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor();
1.886 + waitingToLockBlocker = currentThread->current_park_blocker();
1.887 + st->cr();
1.888 + st->print_cr("\"%s\":", currentThread->get_thread_name());
1.889 + const char* owner_desc = ",\n which is held by";
1.890 + if (waitingToLockMonitor != NULL) {
1.891 + st->print(" waiting to lock monitor " INTPTR_FORMAT, waitingToLockMonitor);
1.892 + oop obj = (oop)waitingToLockMonitor->object();
1.893 + if (obj != NULL) {
1.894 + st->print(" (object "INTPTR_FORMAT ", a %s)", (address)obj,
1.895 + (InstanceKlass::cast(obj->klass()))->external_name());
1.896 +
1.897 + if (!currentThread->current_pending_monitor_is_from_java()) {
1.898 + owner_desc = "\n in JNI, which is held by";
1.899 + }
1.900 + } else {
1.901 + // No Java object associated - a JVMTI raw monitor
1.902 + owner_desc = " (JVMTI raw monitor),\n which is held by";
1.903 + }
1.904 + currentThread = Threads::owning_thread_from_monitor_owner(
1.905 + (address)waitingToLockMonitor->owner(),
1.906 + false /* no locking needed */);
1.907 + if (currentThread == NULL) {
1.908 + // The deadlock was detected at a safepoint so the JavaThread
1.909 + // that owns waitingToLockMonitor should be findable, but
1.910 + // if it is not findable, then the previous currentThread is
1.911 + // blocked permanently.
1.912 + st->print("%s UNKNOWN_owner_addr=" PTR_FORMAT, owner_desc,
1.913 + (address)waitingToLockMonitor->owner());
1.914 + continue;
1.915 + }
1.916 + } else {
1.917 + st->print(" waiting for ownable synchronizer " INTPTR_FORMAT ", (a %s)",
1.918 + (address)waitingToLockBlocker,
1.919 + (InstanceKlass::cast(waitingToLockBlocker->klass()))->external_name());
1.920 + assert(waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass()),
1.921 + "Must be an AbstractOwnableSynchronizer");
1.922 + oop ownerObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker);
1.923 + currentThread = java_lang_Thread::thread(ownerObj);
1.924 + }
1.925 + st->print("%s \"%s\"", owner_desc, currentThread->get_thread_name());
1.926 + }
1.927 +
1.928 + st->cr();
1.929 + st->cr();
1.930 +
1.931 + // Print stack traces
1.932 + bool oldJavaMonitorsInStackTrace = JavaMonitorsInStackTrace;
1.933 + JavaMonitorsInStackTrace = true;
1.934 + st->print_cr("Java stack information for the threads listed above:");
1.935 + st->print_cr("===================================================");
1.936 + for (int j = 0; j < len; j++) {
1.937 + currentThread = _threads->at(j);
1.938 + st->print_cr("\"%s\":", currentThread->get_thread_name());
1.939 + currentThread->print_stack_on(st);
1.940 + }
1.941 + JavaMonitorsInStackTrace = oldJavaMonitorsInStackTrace;
1.942 +}
1.943 +
1.944 +ThreadsListEnumerator::ThreadsListEnumerator(Thread* cur_thread,
1.945 + bool include_jvmti_agent_threads,
1.946 + bool include_jni_attaching_threads) {
1.947 + assert(cur_thread == Thread::current(), "Check current thread");
1.948 +
1.949 + int init_size = ThreadService::get_live_thread_count();
1.950 + _threads_array = new GrowableArray<instanceHandle>(init_size);
1.951 +
1.952 + MutexLockerEx ml(Threads_lock);
1.953 +
1.954 + for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) {
1.955 + // skips JavaThreads in the process of exiting
1.956 + // and also skips VM internal JavaThreads
1.957 + // Threads in _thread_new or _thread_new_trans state are included.
1.958 + // i.e. threads have been started but not yet running.
1.959 + if (jt->threadObj() == NULL ||
1.960 + jt->is_exiting() ||
1.961 + !java_lang_Thread::is_alive(jt->threadObj()) ||
1.962 + jt->is_hidden_from_external_view()) {
1.963 + continue;
1.964 + }
1.965 +
1.966 + // skip agent threads
1.967 + if (!include_jvmti_agent_threads && jt->is_jvmti_agent_thread()) {
1.968 + continue;
1.969 + }
1.970 +
1.971 + // skip jni threads in the process of attaching
1.972 + if (!include_jni_attaching_threads && jt->is_attaching_via_jni()) {
1.973 + continue;
1.974 + }
1.975 +
1.976 + instanceHandle h(cur_thread, (instanceOop) jt->threadObj());
1.977 + _threads_array->append(h);
1.978 + }
1.979 +}
