--- /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<instanceHandle>* 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<mtInternal> {
+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<mtInternal> {
+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<mtInternal> {
+ private:
+ JavaThread* _thread;
+ int _depth; // number of stack frames added
+ bool _with_locked_monitors;
+ GrowableArray<StackFrameInfo*>* _frames;
+ GrowableArray<oop>* _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<oop>* 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<mtInternal> {
+ private:
+ Method* _method;
+ int _bci;
+ GrowableArray<oop>* _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<oop>* locked_monitors() { return _locked_monitors; }
+
+ void print_on(outputStream* st) const;
+};
+
+class ThreadConcurrentLocks : public CHeapObj<mtInternal> {
+private:
+ GrowableArray<instanceOop>* _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<instanceOop>* 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<oop>* 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<mtInternal> {
+ private:
+ bool _is_deadlock;
+ GrowableArray<JavaThread*>* _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<JavaThread*>* threads() { return _threads; }
+ void print_on(outputStream* st) const;
+};
+
+// Utility class to get list of java threads.
+class ThreadsListEnumerator : public StackObj {
+private:
+ GrowableArray<instanceHandle>* _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