| /* |
| * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "classfile/systemDictionary.hpp" |
| #include "memory/allocation.hpp" |
| #include "memory/heapInspection.hpp" |
| #include "memory/oopFactory.hpp" |
| #include "memory/resourceArea.hpp" |
| #include "oops/instanceKlass.hpp" |
| #include "oops/objArrayOop.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/atomic.inline.hpp" |
| #include "runtime/handles.inline.hpp" |
| #include "runtime/init.hpp" |
| #include "runtime/thread.hpp" |
| #include "runtime/vframe.hpp" |
| #include "runtime/thread.inline.hpp" |
| #include "runtime/vmThread.hpp" |
| #include "runtime/vm_operations.hpp" |
| #include "services/threadService.hpp" |
| |
| // TODO: we need to define a naming convention for perf counters |
| // to distinguish counters for: |
| // - standard JSR174 use |
| // - Hotspot extension (public and committed) |
| // - Hotspot extension (private/internal and uncommitted) |
| |
| // Default is disabled. |
| bool ThreadService::_thread_monitoring_contention_enabled = false; |
| bool ThreadService::_thread_cpu_time_enabled = false; |
| bool ThreadService::_thread_allocated_memory_enabled = false; |
| |
| PerfCounter* ThreadService::_total_threads_count = NULL; |
| PerfVariable* ThreadService::_live_threads_count = NULL; |
| PerfVariable* ThreadService::_peak_threads_count = NULL; |
| PerfVariable* ThreadService::_daemon_threads_count = NULL; |
| volatile int ThreadService::_exiting_threads_count = 0; |
| volatile int ThreadService::_exiting_daemon_threads_count = 0; |
| |
| ThreadDumpResult* ThreadService::_threaddump_list = NULL; |
| |
| static const int INITIAL_ARRAY_SIZE = 10; |
| |
| void ThreadService::init() { |
| EXCEPTION_MARK; |
| |
| // These counters are for java.lang.management API support. |
| // They are created even if -XX:-UsePerfData is set and in |
| // that case, they will be allocated on C heap. |
| |
| _total_threads_count = |
| PerfDataManager::create_counter(JAVA_THREADS, "started", |
| PerfData::U_Events, CHECK); |
| |
| _live_threads_count = |
| PerfDataManager::create_variable(JAVA_THREADS, "live", |
| PerfData::U_None, CHECK); |
| |
| _peak_threads_count = |
| PerfDataManager::create_variable(JAVA_THREADS, "livePeak", |
| PerfData::U_None, CHECK); |
| |
| _daemon_threads_count = |
| PerfDataManager::create_variable(JAVA_THREADS, "daemon", |
| PerfData::U_None, CHECK); |
| |
| if (os::is_thread_cpu_time_supported()) { |
| _thread_cpu_time_enabled = true; |
| } |
| |
| _thread_allocated_memory_enabled = true; // Always on, so enable it |
| } |
| |
| void ThreadService::reset_peak_thread_count() { |
| // Acquire the lock to update the peak thread count |
| // to synchronize with thread addition and removal. |
| MutexLockerEx mu(Threads_lock); |
| _peak_threads_count->set_value(get_live_thread_count()); |
| } |
| |
| void ThreadService::add_thread(JavaThread* thread, bool daemon) { |
| // Do not count VM internal or JVMTI agent threads |
| if (thread->is_hidden_from_external_view() || |
| thread->is_jvmti_agent_thread()) { |
| return; |
| } |
| |
| _total_threads_count->inc(); |
| _live_threads_count->inc(); |
| |
| if (_live_threads_count->get_value() > _peak_threads_count->get_value()) { |
| _peak_threads_count->set_value(_live_threads_count->get_value()); |
| } |
| |
| if (daemon) { |
| _daemon_threads_count->inc(); |
| } |
| } |
| |
| void ThreadService::remove_thread(JavaThread* thread, bool daemon) { |
| Atomic::dec((jint*) &_exiting_threads_count); |
| |
| if (thread->is_hidden_from_external_view() || |
| thread->is_jvmti_agent_thread()) { |
| return; |
| } |
| |
| _live_threads_count->set_value(_live_threads_count->get_value() - 1); |
| |
| if (daemon) { |
| _daemon_threads_count->set_value(_daemon_threads_count->get_value() - 1); |
| Atomic::dec((jint*) &_exiting_daemon_threads_count); |
| } |
| } |
| |
| void ThreadService::current_thread_exiting(JavaThread* jt) { |
| assert(jt == JavaThread::current(), "Called by current thread"); |
| Atomic::inc((jint*) &_exiting_threads_count); |
| |
| oop threadObj = jt->threadObj(); |
| if (threadObj != NULL && java_lang_Thread::is_daemon(threadObj)) { |
| Atomic::inc((jint*) &_exiting_daemon_threads_count); |
| } |
| } |
| |
| // FIXME: JVMTI should call this function |
| Handle ThreadService::get_current_contended_monitor(JavaThread* thread) { |
| assert(thread != NULL, "should be non-NULL"); |
| assert(Threads_lock->owned_by_self(), "must grab Threads_lock or be at safepoint"); |
| |
| ObjectMonitor *wait_obj = thread->current_waiting_monitor(); |
| |
| oop obj = NULL; |
| if (wait_obj != NULL) { |
| // thread is doing an Object.wait() call |
| obj = (oop) wait_obj->object(); |
| assert(obj != NULL, "Object.wait() should have an object"); |
| } else { |
| ObjectMonitor *enter_obj = thread->current_pending_monitor(); |
| if (enter_obj != NULL) { |
| // thread is trying to enter() or raw_enter() an ObjectMonitor. |
| obj = (oop) enter_obj->object(); |
| } |
| // If obj == NULL, then ObjectMonitor is raw which doesn't count. |
| } |
| |
| Handle h(obj); |
| return h; |
| } |
| |
| bool ThreadService::set_thread_monitoring_contention(bool flag) { |
| MutexLocker m(Management_lock); |
| |
| bool prev = _thread_monitoring_contention_enabled; |
| _thread_monitoring_contention_enabled = flag; |
| |
| return prev; |
| } |
| |
| bool ThreadService::set_thread_cpu_time_enabled(bool flag) { |
| MutexLocker m(Management_lock); |
| |
| bool prev = _thread_cpu_time_enabled; |
| _thread_cpu_time_enabled = flag; |
| |
| return prev; |
| } |
| |
| bool ThreadService::set_thread_allocated_memory_enabled(bool flag) { |
| MutexLocker m(Management_lock); |
| |
| bool prev = _thread_allocated_memory_enabled; |
| _thread_allocated_memory_enabled = flag; |
| |
| return prev; |
| } |
| |
| // GC support |
| void ThreadService::oops_do(OopClosure* f) { |
| for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) { |
| dump->oops_do(f); |
| } |
| } |
| |
| void ThreadService::metadata_do(void f(Metadata*)) { |
| for (ThreadDumpResult* dump = _threaddump_list; dump != NULL; dump = dump->next()) { |
| dump->metadata_do(f); |
| } |
| } |
| |
| void ThreadService::add_thread_dump(ThreadDumpResult* dump) { |
| MutexLocker ml(Management_lock); |
| if (_threaddump_list == NULL) { |
| _threaddump_list = dump; |
| } else { |
| dump->set_next(_threaddump_list); |
| _threaddump_list = dump; |
| } |
| } |
| |
| void ThreadService::remove_thread_dump(ThreadDumpResult* dump) { |
| MutexLocker ml(Management_lock); |
| |
| ThreadDumpResult* prev = NULL; |
| bool found = false; |
| for (ThreadDumpResult* d = _threaddump_list; d != NULL; prev = d, d = d->next()) { |
| if (d == dump) { |
| if (prev == NULL) { |
| _threaddump_list = dump->next(); |
| } else { |
| prev->set_next(dump->next()); |
| } |
| found = true; |
| break; |
| } |
| } |
| assert(found, "The threaddump result to be removed must exist."); |
| } |
| |
| // Dump stack trace of threads specified in the given threads array. |
| // Returns StackTraceElement[][] each element is the stack trace of a thread in |
| // the corresponding entry in the given threads array |
| Handle ThreadService::dump_stack_traces(GrowableArray<instanceHandle>* threads, |
| int num_threads, |
| TRAPS) { |
| assert(num_threads > 0, "just checking"); |
| |
| ThreadDumpResult dump_result; |
| VM_ThreadDump op(&dump_result, |
| threads, |
| num_threads, |
| -1, /* entire stack */ |
| false, /* with locked monitors */ |
| false /* with locked synchronizers */); |
| VMThread::execute(&op); |
| |
| // Allocate the resulting StackTraceElement[][] object |
| |
| ResourceMark rm(THREAD); |
| Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_StackTraceElement_array(), true, CHECK_NH); |
| ObjArrayKlass* ik = ObjArrayKlass::cast(k); |
| objArrayOop r = oopFactory::new_objArray(ik, num_threads, CHECK_NH); |
| objArrayHandle result_obj(THREAD, r); |
| |
| int num_snapshots = dump_result.num_snapshots(); |
| assert(num_snapshots == num_threads, "Must have num_threads thread snapshots"); |
| int i = 0; |
| for (ThreadSnapshot* ts = dump_result.snapshots(); ts != NULL; i++, ts = ts->next()) { |
| ThreadStackTrace* stacktrace = ts->get_stack_trace(); |
| if (stacktrace == NULL) { |
| // No stack trace |
| result_obj->obj_at_put(i, NULL); |
| } else { |
| // Construct an array of java/lang/StackTraceElement object |
| Handle backtrace_h = stacktrace->allocate_fill_stack_trace_element_array(CHECK_NH); |
| result_obj->obj_at_put(i, backtrace_h()); |
| } |
| } |
| |
| return result_obj; |
| } |
| |
| void ThreadService::reset_contention_count_stat(JavaThread* thread) { |
| ThreadStatistics* stat = thread->get_thread_stat(); |
| if (stat != NULL) { |
| stat->reset_count_stat(); |
| } |
| } |
| |
| void ThreadService::reset_contention_time_stat(JavaThread* thread) { |
| ThreadStatistics* stat = thread->get_thread_stat(); |
| if (stat != NULL) { |
| stat->reset_time_stat(); |
| } |
| } |
| |
| // Find deadlocks involving object monitors and concurrent locks if concurrent_locks is true |
| DeadlockCycle* ThreadService::find_deadlocks_at_safepoint(bool concurrent_locks) { |
| // This code was modified from the original Threads::find_deadlocks code. |
| int globalDfn = 0, thisDfn; |
| ObjectMonitor* waitingToLockMonitor = NULL; |
| oop waitingToLockBlocker = NULL; |
| bool blocked_on_monitor = false; |
| JavaThread *currentThread, *previousThread; |
| int num_deadlocks = 0; |
| |
| for (JavaThread* p = Threads::first(); p != NULL; p = p->next()) { |
| // Initialize the depth-first-number |
| p->set_depth_first_number(-1); |
| } |
| |
| DeadlockCycle* deadlocks = NULL; |
| DeadlockCycle* last = NULL; |
| DeadlockCycle* cycle = new DeadlockCycle(); |
| for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) { |
| if (jt->depth_first_number() >= 0) { |
| // this thread was already visited |
| continue; |
| } |
| |
| thisDfn = globalDfn; |
| jt->set_depth_first_number(globalDfn++); |
| previousThread = jt; |
| currentThread = jt; |
| |
| cycle->reset(); |
| |
| // When there is a deadlock, all the monitors involved in the dependency |
| // cycle must be contended and heavyweight. So we only care about the |
| // heavyweight monitor a thread is waiting to lock. |
| waitingToLockMonitor = (ObjectMonitor*)jt->current_pending_monitor(); |
| if (concurrent_locks) { |
| waitingToLockBlocker = jt->current_park_blocker(); |
| } |
| while (waitingToLockMonitor != NULL || waitingToLockBlocker != NULL) { |
| cycle->add_thread(currentThread); |
| if (waitingToLockMonitor != NULL) { |
| address currentOwner = (address)waitingToLockMonitor->owner(); |
| if (currentOwner != NULL) { |
| currentThread = Threads::owning_thread_from_monitor_owner( |
| currentOwner, |
| false /* no locking needed */); |
| if (currentThread == NULL) { |
| // This function is called at a safepoint so the JavaThread |
| // that owns waitingToLockMonitor should be findable, but |
| // if it is not findable, then the previous currentThread is |
| // blocked permanently. We record this as a deadlock. |
| num_deadlocks++; |
| |
| cycle->set_deadlock(true); |
| |
| // add this cycle to the deadlocks list |
| if (deadlocks == NULL) { |
| deadlocks = cycle; |
| } else { |
| last->set_next(cycle); |
| } |
| last = cycle; |
| cycle = new DeadlockCycle(); |
| break; |
| } |
| } |
| } else { |
| if (concurrent_locks) { |
| if (waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) { |
| oop threadObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker); |
| currentThread = threadObj != NULL ? java_lang_Thread::thread(threadObj) : NULL; |
| } else { |
| currentThread = NULL; |
| } |
| } |
| } |
| |
| if (currentThread == NULL) { |
| // No dependency on another thread |
| break; |
| } |
| if (currentThread->depth_first_number() < 0) { |
| // First visit to this thread |
| currentThread->set_depth_first_number(globalDfn++); |
| } else if (currentThread->depth_first_number() < thisDfn) { |
| // Thread already visited, and not on a (new) cycle |
| break; |
| } else if (currentThread == previousThread) { |
| // Self-loop, ignore |
| break; |
| } else { |
| // We have a (new) cycle |
| num_deadlocks++; |
| |
| cycle->set_deadlock(true); |
| |
| // add this cycle to the deadlocks list |
| if (deadlocks == NULL) { |
| deadlocks = cycle; |
| } else { |
| last->set_next(cycle); |
| } |
| last = cycle; |
| cycle = new DeadlockCycle(); |
| break; |
| } |
| previousThread = currentThread; |
| waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor(); |
| if (concurrent_locks) { |
| waitingToLockBlocker = currentThread->current_park_blocker(); |
| } |
| } |
| |
| } |
| delete cycle; |
| return deadlocks; |
| } |
| |
| ThreadDumpResult::ThreadDumpResult() : _num_threads(0), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) { |
| |
| // Create a new ThreadDumpResult object and append to the list. |
| // If GC happens before this function returns, Method* |
| // in the stack trace will be visited. |
| ThreadService::add_thread_dump(this); |
| } |
| |
| ThreadDumpResult::ThreadDumpResult(int num_threads) : _num_threads(num_threads), _num_snapshots(0), _snapshots(NULL), _next(NULL), _last(NULL) { |
| // Create a new ThreadDumpResult object and append to the list. |
| // If GC happens before this function returns, oops |
| // will be visited. |
| ThreadService::add_thread_dump(this); |
| } |
| |
| ThreadDumpResult::~ThreadDumpResult() { |
| ThreadService::remove_thread_dump(this); |
| |
| // free all the ThreadSnapshot objects created during |
| // the VM_ThreadDump operation |
| ThreadSnapshot* ts = _snapshots; |
| while (ts != NULL) { |
| ThreadSnapshot* p = ts; |
| ts = ts->next(); |
| delete p; |
| } |
| } |
| |
| |
| void ThreadDumpResult::add_thread_snapshot(ThreadSnapshot* ts) { |
| assert(_num_threads == 0 || _num_snapshots < _num_threads, |
| "_num_snapshots must be less than _num_threads"); |
| _num_snapshots++; |
| if (_snapshots == NULL) { |
| _snapshots = ts; |
| } else { |
| _last->set_next(ts); |
| } |
| _last = ts; |
| } |
| |
| void ThreadDumpResult::oops_do(OopClosure* f) { |
| for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) { |
| ts->oops_do(f); |
| } |
| } |
| |
| void ThreadDumpResult::metadata_do(void f(Metadata*)) { |
| for (ThreadSnapshot* ts = _snapshots; ts != NULL; ts = ts->next()) { |
| ts->metadata_do(f); |
| } |
| } |
| |
| StackFrameInfo::StackFrameInfo(javaVFrame* jvf, bool with_lock_info) { |
| _method = jvf->method(); |
| _bci = jvf->bci(); |
| _class_holder = _method->method_holder()->klass_holder(); |
| _locked_monitors = NULL; |
| if (with_lock_info) { |
| ResourceMark rm; |
| GrowableArray<MonitorInfo*>* list = jvf->locked_monitors(); |
| int length = list->length(); |
| if (length > 0) { |
| _locked_monitors = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(length, true); |
| for (int i = 0; i < length; i++) { |
| MonitorInfo* monitor = list->at(i); |
| assert(monitor->owner(), "This monitor must have an owning object"); |
| _locked_monitors->append(monitor->owner()); |
| } |
| } |
| } |
| } |
| |
| void StackFrameInfo::oops_do(OopClosure* f) { |
| if (_locked_monitors != NULL) { |
| int length = _locked_monitors->length(); |
| for (int i = 0; i < length; i++) { |
| f->do_oop((oop*) _locked_monitors->adr_at(i)); |
| } |
| } |
| f->do_oop(&_class_holder); |
| } |
| |
| void StackFrameInfo::metadata_do(void f(Metadata*)) { |
| f(_method); |
| } |
| |
| void StackFrameInfo::print_on(outputStream* st) const { |
| ResourceMark rm; |
| java_lang_Throwable::print_stack_element(st, method(), bci()); |
| int len = (_locked_monitors != NULL ? _locked_monitors->length() : 0); |
| for (int i = 0; i < len; i++) { |
| oop o = _locked_monitors->at(i); |
| st->print_cr("\t- locked <" INTPTR_FORMAT "> (a %s)", p2i(o), o->klass()->external_name()); |
| } |
| |
| } |
| |
| // Iterate through monitor cache to find JNI locked monitors |
| class InflatedMonitorsClosure: public MonitorClosure { |
| private: |
| ThreadStackTrace* _stack_trace; |
| Thread* _thread; |
| public: |
| InflatedMonitorsClosure(Thread* t, ThreadStackTrace* st) { |
| _thread = t; |
| _stack_trace = st; |
| } |
| void do_monitor(ObjectMonitor* mid) { |
| if (mid->owner() == _thread) { |
| oop object = (oop) mid->object(); |
| if (!_stack_trace->is_owned_monitor_on_stack(object)) { |
| _stack_trace->add_jni_locked_monitor(object); |
| } |
| } |
| } |
| }; |
| |
| ThreadStackTrace::ThreadStackTrace(JavaThread* t, bool with_locked_monitors) { |
| _thread = t; |
| _frames = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<StackFrameInfo*>(INITIAL_ARRAY_SIZE, true); |
| _depth = 0; |
| _with_locked_monitors = with_locked_monitors; |
| if (_with_locked_monitors) { |
| _jni_locked_monitors = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<oop>(INITIAL_ARRAY_SIZE, true); |
| } else { |
| _jni_locked_monitors = NULL; |
| } |
| } |
| |
| ThreadStackTrace::~ThreadStackTrace() { |
| for (int i = 0; i < _frames->length(); i++) { |
| delete _frames->at(i); |
| } |
| delete _frames; |
| if (_jni_locked_monitors != NULL) { |
| delete _jni_locked_monitors; |
| } |
| } |
| |
| void ThreadStackTrace::dump_stack_at_safepoint(int maxDepth) { |
| assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); |
| |
| if (_thread->has_last_Java_frame()) { |
| RegisterMap reg_map(_thread); |
| vframe* start_vf = _thread->last_java_vframe(®_map); |
| int count = 0; |
| for (vframe* f = start_vf; f; f = f->sender() ) { |
| if (f->is_java_frame()) { |
| javaVFrame* jvf = javaVFrame::cast(f); |
| add_stack_frame(jvf); |
| count++; |
| } else { |
| // Ignore non-Java frames |
| } |
| if (maxDepth > 0 && count == maxDepth) { |
| // Skip frames if more than maxDepth |
| break; |
| } |
| } |
| } |
| |
| if (_with_locked_monitors) { |
| // Iterate inflated monitors and find monitors locked by this thread |
| // not found in the stack |
| InflatedMonitorsClosure imc(_thread, this); |
| ObjectSynchronizer::monitors_iterate(&imc); |
| } |
| } |
| |
| |
| bool ThreadStackTrace::is_owned_monitor_on_stack(oop object) { |
| assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); |
| |
| bool found = false; |
| int num_frames = get_stack_depth(); |
| for (int depth = 0; depth < num_frames; depth++) { |
| StackFrameInfo* frame = stack_frame_at(depth); |
| int len = frame->num_locked_monitors(); |
| GrowableArray<oop>* locked_monitors = frame->locked_monitors(); |
| for (int j = 0; j < len; j++) { |
| oop monitor = locked_monitors->at(j); |
| assert(monitor != NULL, "must be a Java object"); |
| if (monitor == object) { |
| found = true; |
| break; |
| } |
| } |
| } |
| return found; |
| } |
| |
| Handle ThreadStackTrace::allocate_fill_stack_trace_element_array(TRAPS) { |
| Klass* k = SystemDictionary::StackTraceElement_klass(); |
| assert(k != NULL, "must be loaded in 1.4+"); |
| instanceKlassHandle ik(THREAD, k); |
| |
| // Allocate an array of java/lang/StackTraceElement object |
| objArrayOop ste = oopFactory::new_objArray(ik(), _depth, CHECK_NH); |
| objArrayHandle backtrace(THREAD, ste); |
| for (int j = 0; j < _depth; j++) { |
| StackFrameInfo* frame = _frames->at(j); |
| methodHandle mh(THREAD, frame->method()); |
| oop element = java_lang_StackTraceElement::create(mh, frame->bci(), CHECK_NH); |
| backtrace->obj_at_put(j, element); |
| } |
| return backtrace; |
| } |
| |
| void ThreadStackTrace::add_stack_frame(javaVFrame* jvf) { |
| StackFrameInfo* frame = new StackFrameInfo(jvf, _with_locked_monitors); |
| _frames->append(frame); |
| _depth++; |
| } |
| |
| void ThreadStackTrace::oops_do(OopClosure* f) { |
| int length = _frames->length(); |
| for (int i = 0; i < length; i++) { |
| _frames->at(i)->oops_do(f); |
| } |
| |
| length = (_jni_locked_monitors != NULL ? _jni_locked_monitors->length() : 0); |
| for (int j = 0; j < length; j++) { |
| f->do_oop((oop*) _jni_locked_monitors->adr_at(j)); |
| } |
| } |
| |
| void ThreadStackTrace::metadata_do(void f(Metadata*)) { |
| int length = _frames->length(); |
| for (int i = 0; i < length; i++) { |
| _frames->at(i)->metadata_do(f); |
| } |
| } |
| |
| |
| ConcurrentLocksDump::~ConcurrentLocksDump() { |
| if (_retain_map_on_free) { |
| return; |
| } |
| |
| for (ThreadConcurrentLocks* t = _map; t != NULL;) { |
| ThreadConcurrentLocks* tcl = t; |
| t = t->next(); |
| delete tcl; |
| } |
| } |
| |
| void ConcurrentLocksDump::dump_at_safepoint() { |
| // dump all locked concurrent locks |
| assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped"); |
| |
| ResourceMark rm; |
| |
| GrowableArray<oop>* aos_objects = new GrowableArray<oop>(INITIAL_ARRAY_SIZE); |
| |
| // Find all instances of AbstractOwnableSynchronizer |
| HeapInspection::find_instances_at_safepoint(SystemDictionary::abstract_ownable_synchronizer_klass(), |
| aos_objects); |
| // Build a map of thread to its owned AQS locks |
| build_map(aos_objects); |
| } |
| |
| |
| // build a map of JavaThread to all its owned AbstractOwnableSynchronizer |
| void ConcurrentLocksDump::build_map(GrowableArray<oop>* aos_objects) { |
| int length = aos_objects->length(); |
| for (int i = 0; i < length; i++) { |
| oop o = aos_objects->at(i); |
| oop owner_thread_obj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(o); |
| if (owner_thread_obj != NULL) { |
| JavaThread* thread = java_lang_Thread::thread(owner_thread_obj); |
| assert(o->is_instance(), "Must be an instanceOop"); |
| add_lock(thread, (instanceOop) o); |
| } |
| } |
| } |
| |
| void ConcurrentLocksDump::add_lock(JavaThread* thread, instanceOop o) { |
| ThreadConcurrentLocks* tcl = thread_concurrent_locks(thread); |
| if (tcl != NULL) { |
| tcl->add_lock(o); |
| return; |
| } |
| |
| // First owned lock found for this thread |
| tcl = new ThreadConcurrentLocks(thread); |
| tcl->add_lock(o); |
| if (_map == NULL) { |
| _map = tcl; |
| } else { |
| _last->set_next(tcl); |
| } |
| _last = tcl; |
| } |
| |
| ThreadConcurrentLocks* ConcurrentLocksDump::thread_concurrent_locks(JavaThread* thread) { |
| for (ThreadConcurrentLocks* tcl = _map; tcl != NULL; tcl = tcl->next()) { |
| if (tcl->java_thread() == thread) { |
| return tcl; |
| } |
| } |
| return NULL; |
| } |
| |
| void ConcurrentLocksDump::print_locks_on(JavaThread* t, outputStream* st) { |
| st->print_cr(" Locked ownable synchronizers:"); |
| ThreadConcurrentLocks* tcl = thread_concurrent_locks(t); |
| GrowableArray<instanceOop>* locks = (tcl != NULL ? tcl->owned_locks() : NULL); |
| if (locks == NULL || locks->is_empty()) { |
| st->print_cr("\t- None"); |
| st->cr(); |
| return; |
| } |
| |
| for (int i = 0; i < locks->length(); i++) { |
| instanceOop obj = locks->at(i); |
| st->print_cr("\t- <" INTPTR_FORMAT "> (a %s)", p2i(obj), obj->klass()->external_name()); |
| } |
| st->cr(); |
| } |
| |
| ThreadConcurrentLocks::ThreadConcurrentLocks(JavaThread* thread) { |
| _thread = thread; |
| _owned_locks = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<instanceOop>(INITIAL_ARRAY_SIZE, true); |
| _next = NULL; |
| } |
| |
| ThreadConcurrentLocks::~ThreadConcurrentLocks() { |
| delete _owned_locks; |
| } |
| |
| void ThreadConcurrentLocks::add_lock(instanceOop o) { |
| _owned_locks->append(o); |
| } |
| |
| void ThreadConcurrentLocks::oops_do(OopClosure* f) { |
| int length = _owned_locks->length(); |
| for (int i = 0; i < length; i++) { |
| f->do_oop((oop*) _owned_locks->adr_at(i)); |
| } |
| } |
| |
| ThreadStatistics::ThreadStatistics() { |
| _contended_enter_count = 0; |
| _monitor_wait_count = 0; |
| _sleep_count = 0; |
| _count_pending_reset = false; |
| _timer_pending_reset = false; |
| memset((void*) _perf_recursion_counts, 0, sizeof(_perf_recursion_counts)); |
| } |
| |
| ThreadSnapshot::ThreadSnapshot(JavaThread* thread) { |
| _thread = thread; |
| _threadObj = thread->threadObj(); |
| _stack_trace = NULL; |
| _concurrent_locks = NULL; |
| _next = NULL; |
| |
| ThreadStatistics* stat = thread->get_thread_stat(); |
| _contended_enter_ticks = stat->contended_enter_ticks(); |
| _contended_enter_count = stat->contended_enter_count(); |
| _monitor_wait_ticks = stat->monitor_wait_ticks(); |
| _monitor_wait_count = stat->monitor_wait_count(); |
| _sleep_ticks = stat->sleep_ticks(); |
| _sleep_count = stat->sleep_count(); |
| |
| _blocker_object = NULL; |
| _blocker_object_owner = NULL; |
| |
| _thread_status = java_lang_Thread::get_thread_status(_threadObj); |
| _is_ext_suspended = thread->is_being_ext_suspended(); |
| _is_in_native = (thread->thread_state() == _thread_in_native); |
| |
| if (_thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER || |
| _thread_status == java_lang_Thread::IN_OBJECT_WAIT || |
| _thread_status == java_lang_Thread::IN_OBJECT_WAIT_TIMED) { |
| |
| Handle obj = ThreadService::get_current_contended_monitor(thread); |
| if (obj() == NULL) { |
| // monitor no longer exists; thread is not blocked |
| _thread_status = java_lang_Thread::RUNNABLE; |
| } else { |
| _blocker_object = obj(); |
| JavaThread* owner = ObjectSynchronizer::get_lock_owner(obj, false); |
| if ((owner == NULL && _thread_status == java_lang_Thread::BLOCKED_ON_MONITOR_ENTER) |
| || (owner != NULL && owner->is_attaching_via_jni())) { |
| // ownership information of the monitor is not available |
| // (may no longer be owned or releasing to some other thread) |
| // make this thread in RUNNABLE state. |
| // And when the owner thread is in attaching state, the java thread |
| // is not completely initialized. For example thread name and id |
| // and may not be set, so hide the attaching thread. |
| _thread_status = java_lang_Thread::RUNNABLE; |
| _blocker_object = NULL; |
| } else if (owner != NULL) { |
| _blocker_object_owner = owner->threadObj(); |
| } |
| } |
| } |
| |
| // Support for JSR-166 locks |
| if (JDK_Version::current().supports_thread_park_blocker() && |
| (_thread_status == java_lang_Thread::PARKED || |
| _thread_status == java_lang_Thread::PARKED_TIMED)) { |
| |
| _blocker_object = thread->current_park_blocker(); |
| if (_blocker_object != NULL && _blocker_object->is_a(SystemDictionary::abstract_ownable_synchronizer_klass())) { |
| _blocker_object_owner = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(_blocker_object); |
| } |
| } |
| } |
| |
| ThreadSnapshot::~ThreadSnapshot() { |
| delete _stack_trace; |
| delete _concurrent_locks; |
| } |
| |
| void ThreadSnapshot::dump_stack_at_safepoint(int max_depth, bool with_locked_monitors) { |
| _stack_trace = new ThreadStackTrace(_thread, with_locked_monitors); |
| _stack_trace->dump_stack_at_safepoint(max_depth); |
| } |
| |
| |
| void ThreadSnapshot::oops_do(OopClosure* f) { |
| f->do_oop(&_threadObj); |
| f->do_oop(&_blocker_object); |
| f->do_oop(&_blocker_object_owner); |
| if (_stack_trace != NULL) { |
| _stack_trace->oops_do(f); |
| } |
| if (_concurrent_locks != NULL) { |
| _concurrent_locks->oops_do(f); |
| } |
| } |
| |
| void ThreadSnapshot::metadata_do(void f(Metadata*)) { |
| if (_stack_trace != NULL) { |
| _stack_trace->metadata_do(f); |
| } |
| } |
| |
| |
| DeadlockCycle::DeadlockCycle() { |
| _is_deadlock = false; |
| _threads = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<JavaThread*>(INITIAL_ARRAY_SIZE, true); |
| _next = NULL; |
| } |
| |
| DeadlockCycle::~DeadlockCycle() { |
| delete _threads; |
| } |
| |
| void DeadlockCycle::print_on(outputStream* st) const { |
| st->cr(); |
| st->print_cr("Found one Java-level deadlock:"); |
| st->print("============================="); |
| |
| JavaThread* currentThread; |
| ObjectMonitor* waitingToLockMonitor; |
| oop waitingToLockBlocker; |
| int len = _threads->length(); |
| for (int i = 0; i < len; i++) { |
| currentThread = _threads->at(i); |
| waitingToLockMonitor = (ObjectMonitor*)currentThread->current_pending_monitor(); |
| waitingToLockBlocker = currentThread->current_park_blocker(); |
| st->cr(); |
| st->print_cr("\"%s\":", currentThread->get_thread_name()); |
| const char* owner_desc = ",\n which is held by"; |
| if (waitingToLockMonitor != NULL) { |
| st->print(" waiting to lock monitor " INTPTR_FORMAT, p2i(waitingToLockMonitor)); |
| oop obj = (oop)waitingToLockMonitor->object(); |
| if (obj != NULL) { |
| st->print(" (object " INTPTR_FORMAT ", a %s)", p2i(obj), |
| obj->klass()->external_name()); |
| |
| if (!currentThread->current_pending_monitor_is_from_java()) { |
| owner_desc = "\n in JNI, which is held by"; |
| } |
| } else { |
| // No Java object associated - a JVMTI raw monitor |
| owner_desc = " (JVMTI raw monitor),\n which is held by"; |
| } |
| currentThread = Threads::owning_thread_from_monitor_owner( |
| (address)waitingToLockMonitor->owner(), |
| false /* no locking needed */); |
| if (currentThread == NULL) { |
| // The deadlock was detected at a safepoint so the JavaThread |
| // that owns waitingToLockMonitor should be findable, but |
| // if it is not findable, then the previous currentThread is |
| // blocked permanently. |
| st->print("%s UNKNOWN_owner_addr=" PTR_FORMAT, owner_desc, |
| p2i(waitingToLockMonitor->owner())); |
| continue; |
| } |
| } else { |
| st->print(" waiting for ownable synchronizer " INTPTR_FORMAT ", (a %s)", |
| p2i(waitingToLockBlocker), |
| waitingToLockBlocker->klass()->external_name()); |
| assert(waitingToLockBlocker->is_a(SystemDictionary::abstract_ownable_synchronizer_klass()), |
| "Must be an AbstractOwnableSynchronizer"); |
| oop ownerObj = java_util_concurrent_locks_AbstractOwnableSynchronizer::get_owner_threadObj(waitingToLockBlocker); |
| currentThread = java_lang_Thread::thread(ownerObj); |
| } |
| st->print("%s \"%s\"", owner_desc, currentThread->get_thread_name()); |
| } |
| |
| st->cr(); |
| st->cr(); |
| |
| // Print stack traces |
| bool oldJavaMonitorsInStackTrace = JavaMonitorsInStackTrace; |
| JavaMonitorsInStackTrace = true; |
| st->print_cr("Java stack information for the threads listed above:"); |
| st->print_cr("==================================================="); |
| for (int j = 0; j < len; j++) { |
| currentThread = _threads->at(j); |
| st->print_cr("\"%s\":", currentThread->get_thread_name()); |
| currentThread->print_stack_on(st); |
| } |
| JavaMonitorsInStackTrace = oldJavaMonitorsInStackTrace; |
| } |
| |
| ThreadsListEnumerator::ThreadsListEnumerator(Thread* cur_thread, |
| bool include_jvmti_agent_threads, |
| bool include_jni_attaching_threads) { |
| assert(cur_thread == Thread::current(), "Check current thread"); |
| |
| int init_size = ThreadService::get_live_thread_count(); |
| _threads_array = new GrowableArray<instanceHandle>(init_size); |
| |
| MutexLockerEx ml(Threads_lock); |
| |
| for (JavaThread* jt = Threads::first(); jt != NULL; jt = jt->next()) { |
| // skips JavaThreads in the process of exiting |
| // and also skips VM internal JavaThreads |
| // Threads in _thread_new or _thread_new_trans state are included. |
| // i.e. threads have been started but not yet running. |
| if (jt->threadObj() == NULL || |
| jt->is_exiting() || |
| !java_lang_Thread::is_alive(jt->threadObj()) || |
| jt->is_hidden_from_external_view()) { |
| continue; |
| } |
| |
| // skip agent threads |
| if (!include_jvmti_agent_threads && jt->is_jvmti_agent_thread()) { |
| continue; |
| } |
| |
| // skip jni threads in the process of attaching |
| if (!include_jni_attaching_threads && jt->is_attaching_via_jni()) { |
| continue; |
| } |
| |
| instanceHandle h(cur_thread, (instanceOop) jt->threadObj()); |
| _threads_array->append(h); |
| } |
| } |