diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/services/threadService.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/services/threadService.hpp Tue Sep 12 19:03:39 2017 +0200 @@ -0,0 +1,592 @@ +/* + * Copyright (c) 2003, 2013, 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. + * + */ + +#ifndef SHARE_VM_SERVICES_THREADSERVICE_HPP +#define SHARE_VM_SERVICES_THREADSERVICE_HPP + +#include "classfile/javaClasses.hpp" +#include "runtime/handles.hpp" +#include "runtime/init.hpp" +#include "runtime/jniHandles.hpp" +#include "runtime/objectMonitor.hpp" +#include "runtime/objectMonitor.inline.hpp" +#include "runtime/perfData.hpp" +#include "services/management.hpp" +#include "services/serviceUtil.hpp" + +class OopClosure; +class ThreadDumpResult; +class ThreadStackTrace; +class ThreadSnapshot; +class StackFrameInfo; +class ThreadConcurrentLocks; +class DeadlockCycle; + +// VM monitoring and management support for the thread and +// synchronization subsystem +// +// Thread contention monitoring is disabled by default. +// When enabled, the VM will begin measuring the accumulated +// elapsed time a thread blocked on synchronization. +// +class ThreadService : public AllStatic { +private: + // These counters could be moved to Threads class + static PerfCounter* _total_threads_count; + static PerfVariable* _live_threads_count; + static PerfVariable* _peak_threads_count; + static PerfVariable* _daemon_threads_count; + + // These 2 counters are atomically incremented once the thread is exiting. + // They will be atomically decremented when ThreadService::remove_thread is called. + static volatile int _exiting_threads_count; + static volatile int _exiting_daemon_threads_count; + + static bool _thread_monitoring_contention_enabled; + static bool _thread_cpu_time_enabled; + static bool _thread_allocated_memory_enabled; + + // Need to keep the list of thread dump result that + // keep references to Method* since thread dump can be + // requested by multiple threads concurrently. + static ThreadDumpResult* _threaddump_list; + +public: + static void init(); + static void add_thread(JavaThread* thread, bool daemon); + static void remove_thread(JavaThread* thread, bool daemon); + static void current_thread_exiting(JavaThread* jt); + + static bool set_thread_monitoring_contention(bool flag); + static bool is_thread_monitoring_contention() { return _thread_monitoring_contention_enabled; } + + static bool set_thread_cpu_time_enabled(bool flag); + static bool is_thread_cpu_time_enabled() { return _thread_cpu_time_enabled; } + + static bool set_thread_allocated_memory_enabled(bool flag); + static bool is_thread_allocated_memory_enabled() { return _thread_cpu_time_enabled; } + + static jlong get_total_thread_count() { return _total_threads_count->get_value(); } + static jlong get_peak_thread_count() { return _peak_threads_count->get_value(); } + static jlong get_live_thread_count() { return _live_threads_count->get_value() - _exiting_threads_count; } + static jlong get_daemon_thread_count() { return _daemon_threads_count->get_value() - _exiting_daemon_threads_count; } + + static int exiting_threads_count() { return _exiting_threads_count; } + static int exiting_daemon_threads_count() { return _exiting_daemon_threads_count; } + + // Support for thread dump + static void add_thread_dump(ThreadDumpResult* dump); + static void remove_thread_dump(ThreadDumpResult* dump); + + static Handle get_current_contended_monitor(JavaThread* thread); + + // This function is called by JVM_DumpThreads. + static Handle dump_stack_traces(GrowableArray* threads, + int num_threads, TRAPS); + + static void reset_peak_thread_count(); + static void reset_contention_count_stat(JavaThread* thread); + static void reset_contention_time_stat(JavaThread* thread); + + static DeadlockCycle* find_deadlocks_at_safepoint(bool object_monitors_only); + + // GC support + static void oops_do(OopClosure* f); + static void metadata_do(void f(Metadata*)); +}; + +// Per-thread Statistics for synchronization +class ThreadStatistics : public CHeapObj { +private: + // The following contention statistics are only updated by + // the thread owning these statistics when contention occurs. + + jlong _contended_enter_count; + elapsedTimer _contended_enter_timer; + jlong _monitor_wait_count; + elapsedTimer _monitor_wait_timer; + jlong _sleep_count; + elapsedTimer _sleep_timer; + + + // These two reset flags are set to true when another thread + // requests to reset the statistics. The actual statistics + // are reset when the thread contention occurs and attempts + // to update the statistics. + bool _count_pending_reset; + bool _timer_pending_reset; + + // Keep accurate times for potentially recursive class operations + int _perf_recursion_counts[6]; + elapsedTimer _perf_timers[6]; + + // utility functions + void check_and_reset_count() { + if (!_count_pending_reset) return; + _contended_enter_count = 0; + _monitor_wait_count = 0; + _sleep_count = 0; + _count_pending_reset = 0; + } + void check_and_reset_timer() { + if (!_timer_pending_reset) return; + _contended_enter_timer.reset(); + _monitor_wait_timer.reset(); + _sleep_timer.reset(); + _timer_pending_reset = 0; + } + +public: + ThreadStatistics(); + + jlong contended_enter_count() { return (_count_pending_reset ? 0 : _contended_enter_count); } + jlong contended_enter_ticks() { return (_timer_pending_reset ? 0 : _contended_enter_timer.active_ticks()); } + jlong monitor_wait_count() { return (_count_pending_reset ? 0 : _monitor_wait_count); } + jlong monitor_wait_ticks() { return (_timer_pending_reset ? 0 : _monitor_wait_timer.active_ticks()); } + jlong sleep_count() { return (_count_pending_reset ? 0 : _sleep_count); } + jlong sleep_ticks() { return (_timer_pending_reset ? 0 : _sleep_timer.active_ticks()); } + + void monitor_wait() { check_and_reset_count(); _monitor_wait_count++; } + void monitor_wait_begin() { check_and_reset_timer(); _monitor_wait_timer.start(); } + void monitor_wait_end() { _monitor_wait_timer.stop(); check_and_reset_timer(); } + + void thread_sleep() { check_and_reset_count(); _sleep_count++; } + void thread_sleep_begin() { check_and_reset_timer(); _sleep_timer.start(); } + void thread_sleep_end() { _sleep_timer.stop(); check_and_reset_timer(); } + + void contended_enter() { check_and_reset_count(); _contended_enter_count++; } + void contended_enter_begin() { check_and_reset_timer(); _contended_enter_timer.start(); } + void contended_enter_end() { _contended_enter_timer.stop(); check_and_reset_timer(); } + + void reset_count_stat() { _count_pending_reset = true; } + void reset_time_stat() { _timer_pending_reset = true; } + + int* perf_recursion_counts_addr() { return _perf_recursion_counts; } + elapsedTimer* perf_timers_addr() { return _perf_timers; } +}; + +// Thread snapshot to represent the thread state and statistics +class ThreadSnapshot : public CHeapObj { +private: + JavaThread* _thread; + oop _threadObj; + java_lang_Thread::ThreadStatus _thread_status; + + bool _is_ext_suspended; + bool _is_in_native; + + jlong _contended_enter_ticks; + jlong _contended_enter_count; + jlong _monitor_wait_ticks; + jlong _monitor_wait_count; + jlong _sleep_ticks; + jlong _sleep_count; + oop _blocker_object; + oop _blocker_object_owner; + + ThreadStackTrace* _stack_trace; + ThreadConcurrentLocks* _concurrent_locks; + ThreadSnapshot* _next; + +public: + // Dummy snapshot + ThreadSnapshot() : _thread(NULL), _threadObj(NULL), _stack_trace(NULL), _concurrent_locks(NULL), _next(NULL), + _blocker_object(NULL), _blocker_object_owner(NULL) {}; + ThreadSnapshot(JavaThread* thread); + ~ThreadSnapshot(); + + java_lang_Thread::ThreadStatus thread_status() { return _thread_status; } + + oop threadObj() const { return _threadObj; } + + void set_next(ThreadSnapshot* n) { _next = n; } + + bool is_ext_suspended() { return _is_ext_suspended; } + bool is_in_native() { return _is_in_native; } + + jlong contended_enter_count() { return _contended_enter_count; } + jlong contended_enter_ticks() { return _contended_enter_ticks; } + jlong monitor_wait_count() { return _monitor_wait_count; } + jlong monitor_wait_ticks() { return _monitor_wait_ticks; } + jlong sleep_count() { return _sleep_count; } + jlong sleep_ticks() { return _sleep_ticks; } + + + oop blocker_object() { return _blocker_object; } + oop blocker_object_owner() { return _blocker_object_owner; } + + ThreadSnapshot* next() const { return _next; } + ThreadStackTrace* get_stack_trace() { return _stack_trace; } + ThreadConcurrentLocks* get_concurrent_locks() { return _concurrent_locks; } + + void dump_stack_at_safepoint(int max_depth, bool with_locked_monitors); + void set_concurrent_locks(ThreadConcurrentLocks* l) { _concurrent_locks = l; } + void oops_do(OopClosure* f); + void metadata_do(void f(Metadata*)); +}; + +class ThreadStackTrace : public CHeapObj { + private: + JavaThread* _thread; + int _depth; // number of stack frames added + bool _with_locked_monitors; + GrowableArray* _frames; + GrowableArray* _jni_locked_monitors; + + public: + + ThreadStackTrace(JavaThread* thread, bool with_locked_monitors); + ~ThreadStackTrace(); + + JavaThread* thread() { return _thread; } + StackFrameInfo* stack_frame_at(int i) { return _frames->at(i); } + int get_stack_depth() { return _depth; } + + void add_stack_frame(javaVFrame* jvf); + void dump_stack_at_safepoint(int max_depth); + Handle allocate_fill_stack_trace_element_array(TRAPS); + void oops_do(OopClosure* f); + void metadata_do(void f(Metadata*)); + GrowableArray* jni_locked_monitors() { return _jni_locked_monitors; } + int num_jni_locked_monitors() { return (_jni_locked_monitors != NULL ? _jni_locked_monitors->length() : 0); } + + bool is_owned_monitor_on_stack(oop object); + void add_jni_locked_monitor(oop object) { _jni_locked_monitors->append(object); } +}; + +// StackFrameInfo for keeping Method* and bci during +// stack walking for later construction of StackTraceElement[] +// Java instances +class StackFrameInfo : public CHeapObj { + private: + Method* _method; + int _bci; + GrowableArray* _locked_monitors; // list of object monitors locked by this frame + // We need to save the mirrors in the backtrace to keep the class + // from being unloaded while we still have this stack trace. + oop _class_holder; + + public: + + StackFrameInfo(javaVFrame* jvf, bool with_locked_monitors); + ~StackFrameInfo() { + if (_locked_monitors != NULL) { + delete _locked_monitors; + } + }; + Method* method() const { return _method; } + int bci() const { return _bci; } + void oops_do(OopClosure* f); + void metadata_do(void f(Metadata*)); + + int num_locked_monitors() { return (_locked_monitors != NULL ? _locked_monitors->length() : 0); } + GrowableArray* locked_monitors() { return _locked_monitors; } + + void print_on(outputStream* st) const; +}; + +class ThreadConcurrentLocks : public CHeapObj { +private: + GrowableArray* _owned_locks; + ThreadConcurrentLocks* _next; + JavaThread* _thread; + public: + ThreadConcurrentLocks(JavaThread* thread); + ~ThreadConcurrentLocks(); + + void add_lock(instanceOop o); + void set_next(ThreadConcurrentLocks* n) { _next = n; } + ThreadConcurrentLocks* next() { return _next; } + JavaThread* java_thread() { return _thread; } + GrowableArray* owned_locks() { return _owned_locks; } + void oops_do(OopClosure* f); +}; + +class ConcurrentLocksDump : public StackObj { + private: + ThreadConcurrentLocks* _map; + ThreadConcurrentLocks* _last; // Last ThreadConcurrentLocks in the map + bool _retain_map_on_free; + + void build_map(GrowableArray* aos_objects); + void add_lock(JavaThread* thread, instanceOop o); + + public: + ConcurrentLocksDump(bool retain_map_on_free) : _map(NULL), _last(NULL), _retain_map_on_free(retain_map_on_free) {}; + ConcurrentLocksDump() : _map(NULL), _last(NULL), _retain_map_on_free(false) {}; + ~ConcurrentLocksDump(); + + void dump_at_safepoint(); + ThreadConcurrentLocks* thread_concurrent_locks(JavaThread* thread); + void print_locks_on(JavaThread* t, outputStream* st); +}; + +class ThreadDumpResult : public StackObj { + private: + int _num_threads; + int _num_snapshots; + ThreadSnapshot* _snapshots; + ThreadSnapshot* _last; + ThreadDumpResult* _next; + public: + ThreadDumpResult(); + ThreadDumpResult(int num_threads); + ~ThreadDumpResult(); + + void add_thread_snapshot(ThreadSnapshot* ts); + void set_next(ThreadDumpResult* next) { _next = next; } + ThreadDumpResult* next() { return _next; } + int num_threads() { return _num_threads; } + int num_snapshots() { return _num_snapshots; } + ThreadSnapshot* snapshots() { return _snapshots; } + void oops_do(OopClosure* f); + void metadata_do(void f(Metadata*)); +}; + +class DeadlockCycle : public CHeapObj { + private: + bool _is_deadlock; + GrowableArray* _threads; + DeadlockCycle* _next; + public: + DeadlockCycle(); + ~DeadlockCycle(); + + DeadlockCycle* next() { return _next; } + void set_next(DeadlockCycle* d) { _next = d; } + void add_thread(JavaThread* t) { _threads->append(t); } + void reset() { _is_deadlock = false; _threads->clear(); } + void set_deadlock(bool value) { _is_deadlock = value; } + bool is_deadlock() { return _is_deadlock; } + int num_threads() { return _threads->length(); } + GrowableArray* threads() { return _threads; } + void print_on(outputStream* st) const; +}; + +// Utility class to get list of java threads. +class ThreadsListEnumerator : public StackObj { +private: + GrowableArray* _threads_array; +public: + ThreadsListEnumerator(Thread* cur_thread, + bool include_jvmti_agent_threads = false, + bool include_jni_attaching_threads = true); + int num_threads() { return _threads_array->length(); } + instanceHandle get_threadObj(int index) { return _threads_array->at(index); } +}; + + +// abstract utility class to set new thread states, and restore previous after the block exits +class JavaThreadStatusChanger : public StackObj { + private: + java_lang_Thread::ThreadStatus _old_state; + JavaThread* _java_thread; + bool _is_alive; + + void save_old_state(JavaThread* java_thread) { + _java_thread = java_thread; + _is_alive = is_alive(java_thread); + if (is_alive()) { + _old_state = java_lang_Thread::get_thread_status(_java_thread->threadObj()); + } + } + + public: + static void set_thread_status(JavaThread* java_thread, + java_lang_Thread::ThreadStatus state) { + java_lang_Thread::set_thread_status(java_thread->threadObj(), state); + } + + void set_thread_status(java_lang_Thread::ThreadStatus state) { + if (is_alive()) { + set_thread_status(_java_thread, state); + } + } + + JavaThreadStatusChanger(JavaThread* java_thread, + java_lang_Thread::ThreadStatus state) : _old_state(java_lang_Thread::NEW) { + save_old_state(java_thread); + set_thread_status(state); + } + + JavaThreadStatusChanger(JavaThread* java_thread) : _old_state(java_lang_Thread::NEW) { + save_old_state(java_thread); + } + + ~JavaThreadStatusChanger() { + set_thread_status(_old_state); + } + + static bool is_alive(JavaThread* java_thread) { + return java_thread != NULL && java_thread->threadObj() != NULL; + } + + bool is_alive() { + return _is_alive; + } +}; + +// Change status to waiting on an object (timed or indefinite) +class JavaThreadInObjectWaitState : public JavaThreadStatusChanger { + private: + ThreadStatistics* _stat; + bool _active; + + public: + JavaThreadInObjectWaitState(JavaThread *java_thread, bool timed) : + JavaThreadStatusChanger(java_thread, + timed ? java_lang_Thread::IN_OBJECT_WAIT_TIMED : java_lang_Thread::IN_OBJECT_WAIT) { + if (is_alive()) { + _stat = java_thread->get_thread_stat(); + _active = ThreadService::is_thread_monitoring_contention(); + _stat->monitor_wait(); + if (_active) { + _stat->monitor_wait_begin(); + } + } else { + _active = false; + } + } + + ~JavaThreadInObjectWaitState() { + if (_active) { + _stat->monitor_wait_end(); + } + } +}; + +// Change status to parked (timed or indefinite) +class JavaThreadParkedState : public JavaThreadStatusChanger { + private: + ThreadStatistics* _stat; + bool _active; + + public: + JavaThreadParkedState(JavaThread *java_thread, bool timed) : + JavaThreadStatusChanger(java_thread, + timed ? java_lang_Thread::PARKED_TIMED : java_lang_Thread::PARKED) { + if (is_alive()) { + _stat = java_thread->get_thread_stat(); + _active = ThreadService::is_thread_monitoring_contention(); + _stat->monitor_wait(); + if (_active) { + _stat->monitor_wait_begin(); + } + } else { + _active = false; + } + } + + ~JavaThreadParkedState() { + if (_active) { + _stat->monitor_wait_end(); + } + } +}; + +// Change status to blocked on (re-)entering a synchronization block +class JavaThreadBlockedOnMonitorEnterState : public JavaThreadStatusChanger { + private: + ThreadStatistics* _stat; + bool _active; + + static bool contended_enter_begin(JavaThread *java_thread) { + set_thread_status(java_thread, java_lang_Thread::BLOCKED_ON_MONITOR_ENTER); + ThreadStatistics* stat = java_thread->get_thread_stat(); + stat->contended_enter(); + bool active = ThreadService::is_thread_monitoring_contention(); + if (active) { + stat->contended_enter_begin(); + } + return active; + } + + public: + // java_thread is waiting thread being blocked on monitor reenter. + // Current thread is the notifying thread which holds the monitor. + static bool wait_reenter_begin(JavaThread *java_thread, ObjectMonitor *obj_m) { + assert((java_thread != NULL), "Java thread should not be null here"); + bool active = false; + if (is_alive(java_thread) && ServiceUtil::visible_oop((oop)obj_m->object())) { + active = contended_enter_begin(java_thread); + } + return active; + } + + static void wait_reenter_end(JavaThread *java_thread, bool active) { + if (active) { + java_thread->get_thread_stat()->contended_enter_end(); + } + set_thread_status(java_thread, java_lang_Thread::RUNNABLE); + } + + JavaThreadBlockedOnMonitorEnterState(JavaThread *java_thread, ObjectMonitor *obj_m) : + _stat(NULL), _active(false), JavaThreadStatusChanger(java_thread) { + assert((java_thread != NULL), "Java thread should not be null here"); + // Change thread status and collect contended enter stats for monitor contended + // enter done for external java world objects and it is contended. All other cases + // like for vm internal objects and for external objects which are not contended + // thread status is not changed and contended enter stat is not collected. + _active = false; + if (is_alive() && ServiceUtil::visible_oop((oop)obj_m->object()) && obj_m->contentions() > 0) { + _stat = java_thread->get_thread_stat(); + _active = contended_enter_begin(java_thread); + } + } + + ~JavaThreadBlockedOnMonitorEnterState() { + if (_active) { + _stat->contended_enter_end(); + } + } +}; + +// Change status to sleeping +class JavaThreadSleepState : public JavaThreadStatusChanger { + private: + ThreadStatistics* _stat; + bool _active; + public: + JavaThreadSleepState(JavaThread *java_thread) : + JavaThreadStatusChanger(java_thread, java_lang_Thread::SLEEPING) { + if (is_alive()) { + _stat = java_thread->get_thread_stat(); + _active = ThreadService::is_thread_monitoring_contention(); + _stat->thread_sleep(); + if (_active) { + _stat->thread_sleep_begin(); + } + } else { + _active = false; + } + } + + ~JavaThreadSleepState() { + if (_active) { + _stat->thread_sleep_end(); + } + } +}; + +#endif // SHARE_VM_SERVICES_THREADSERVICE_HPP