truffle: src/share/vm/services/memTracker.cpp comparison

comparison src/share/vm/services/memTracker.cpp @ 6275:957c266d8bc5

Merge with http://hg.openjdk.java.net/hsx/hsx24/hotspot/

author	Doug Simon <doug.simon@oracle.com>
date	Tue, 21 Aug 2012 10:39:19 +0200
parents	58a04a45a549
children	e5bf1c79ed5b

comparison

equal deleted inserted replaced

-:fd8832ae511d
+:957c266d8bc5
+/*
+* Copyright (c) 2012, 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 "runtime/atomic.hpp"
+#include "runtime/interfaceSupport.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "runtime/safepoint.hpp"
+#include "runtime/threadCritical.hpp"
+#include "services/memPtr.hpp"
+#include "services/memReporter.hpp"
+#include "services/memTracker.hpp"
+#include "utilities/decoder.hpp"
+#include "utilities/globalDefinitions.hpp"
+bool NMT_track_callsite = false;
+// walk all 'known' threads at NMT sync point, and collect their recorders
+void SyncThreadRecorderClosure::do_thread(Thread* thread) {
+assert(SafepointSynchronize::is_at_safepoint(), "Safepoint required");
+if (thread->is_Java_thread()) {
+JavaThread* javaThread = (JavaThread*)thread;
+MemRecorder* recorder = javaThread->get_recorder();
+if (recorder != NULL) {
+MemTracker::enqueue_pending_recorder(recorder);
+javaThread->set_recorder(NULL);
+}
+}
+_thread_count ++;
+}
+MemRecorder*                    MemTracker::_global_recorder = NULL;
+MemSnapshot*                    MemTracker::_snapshot = NULL;
+MemBaseline                     MemTracker::_baseline;
+Mutex*                          MemTracker::_query_lock = NULL;
+volatile MemRecorder*           MemTracker::_merge_pending_queue = NULL;
+volatile MemRecorder*           MemTracker::_pooled_recorders = NULL;
+MemTrackWorker*                 MemTracker::_worker_thread = NULL;
+int                             MemTracker::_sync_point_skip_count = 0;
+MemTracker::NMTLevel            MemTracker::_tracking_level = MemTracker::NMT_off;
+volatile MemTracker::NMTStates  MemTracker::_state = NMT_uninited;
+MemTracker::ShutdownReason      MemTracker::_reason = NMT_shutdown_none;
+int                             MemTracker::_thread_count = 255;
+volatile jint                   MemTracker::_pooled_recorder_count = 0;
+debug_only(intx                 MemTracker::_main_thread_tid = 0;)
+debug_only(volatile jint        MemTracker::_pending_recorder_count = 0;)
+void MemTracker::init_tracking_options(const char* option_line) {
+_tracking_level = NMT_off;
+if (strncmp(option_line, "=summary", 8) == 0) {
+_tracking_level = NMT_summary;
+} else if (strncmp(option_line, "=detail", 8) == 0) {
+_tracking_level = NMT_detail;
+}
+}
+// first phase of bootstrapping, when VM is still in single-threaded mode.
+void MemTracker::bootstrap_single_thread() {
+if (_tracking_level > NMT_off) {
+assert(_state == NMT_uninited, "wrong state");
+// NMT is not supported with UseMallocOnly is on. NMT can NOT
+// handle the amount of malloc data without significantly impacting
+// runtime performance when this flag is on.
+if (UseMallocOnly) {
+shutdown(NMT_use_malloc_only);
+return;
+}
+_query_lock = new (std::nothrow) Mutex(Monitor::max_nonleaf, "NMT_queryLock");
+if (_query_lock == NULL) {
+shutdown(NMT_out_of_memory);
+return;
+}
+debug_only(_main_thread_tid = os::current_thread_id();)
+_state = NMT_bootstrapping_single_thread;
+NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack());
+}
+}
+// second phase of bootstrapping, when VM is about to or already entered multi-theaded mode.
+void MemTracker::bootstrap_multi_thread() {
+if (_tracking_level > NMT_off && _state == NMT_bootstrapping_single_thread) {
+// create nmt lock for multi-thread execution
+assert(_main_thread_tid == os::current_thread_id(), "wrong thread");
+_state = NMT_bootstrapping_multi_thread;
+NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack());
+}
+}
+// fully start nmt
+void MemTracker::start() {
+// Native memory tracking is off from command line option
+if (_tracking_level == NMT_off || shutdown_in_progress()) return;
+assert(_main_thread_tid == os::current_thread_id(), "wrong thread");
+assert(_state == NMT_bootstrapping_multi_thread, "wrong state");
+_snapshot = new (std::nothrow)MemSnapshot();
+if (_snapshot != NULL && !_snapshot->out_of_memory()) {
+if (start_worker()) {
+_state = NMT_started;
+NMT_track_callsite = (_tracking_level == NMT_detail && can_walk_stack());
+return;
+}
+}
+// fail to start native memory tracking, shut it down
+shutdown(NMT_initialization);
+}
+/**
+* Shutting down native memory tracking.
+* We can not shutdown native memory tracking immediately, so we just
+* setup shutdown pending flag, every native memory tracking component
+* should orderly shut itself down.
+*
+* The shutdown sequences:
+*  1. MemTracker::shutdown() sets MemTracker to shutdown pending state
+*  2. Worker thread calls MemTracker::final_shutdown(), which transites
+*     MemTracker to final shutdown state.
+*  3. At sync point, MemTracker does final cleanup, before sets memory
+*     tracking level to off to complete shutdown.
+*/
+void MemTracker::shutdown(ShutdownReason reason) {
+if (_tracking_level == NMT_off) return;
+if (_state <= NMT_bootstrapping_single_thread) {
+// we still in single thread mode, there is not contention
+_state = NMT_shutdown_pending;
+_reason = reason;
+} else {
+// we want to know who initialized shutdown
+if ((jint)NMT_started == Atomic::cmpxchg((jint)NMT_shutdown_pending,
+(jint*)&_state, (jint)NMT_started)) {
+_reason = reason;
+}
+}
+}
+// final phase of shutdown
+void MemTracker::final_shutdown() {
+// delete all pending recorders and pooled recorders
+delete_all_pending_recorders();
+delete_all_pooled_recorders();
+{
+// shared baseline and snapshot are the only objects needed to
+// create query results
+MutexLockerEx locker(_query_lock, true);
+// cleanup baseline data and snapshot
+_baseline.clear();
+delete _snapshot;
+_snapshot = NULL;
+}
+// shutdown shared decoder instance, since it is only
+// used by native memory tracking so far.
+Decoder::shutdown();
+MemTrackWorker* worker = NULL;
+{
+ThreadCritical tc;
+// can not delete worker inside the thread critical
+if (_worker_thread != NULL && Thread::current() == _worker_thread) {
+worker = _worker_thread;
+_worker_thread = NULL;
+}
+}
+if (worker != NULL) {
+delete worker;
+}
+_state = NMT_final_shutdown;
+}
+// delete all pooled recorders
+void MemTracker::delete_all_pooled_recorders() {
+// free all pooled recorders
+volatile MemRecorder* cur_head = _pooled_recorders;
+if (cur_head != NULL) {
+MemRecorder* null_ptr = NULL;
+while (cur_head != NULL && (void*)cur_head != Atomic::cmpxchg_ptr((void*)null_ptr,
+(void*)&_pooled_recorders, (void*)cur_head)) {
+cur_head = _pooled_recorders;
+}
+if (cur_head != NULL) {
+delete cur_head;
+_pooled_recorder_count = 0;
+}
+}
+}
+// delete all recorders in pending queue
+void MemTracker::delete_all_pending_recorders() {
+// free all pending recorders
+MemRecorder* pending_head = get_pending_recorders();
+if (pending_head != NULL) {
+delete pending_head;
+}
+}
+/*
+* retrieve per-thread recorder of specified thread.
+* if thread == NULL, it means global recorder
+*/
+MemRecorder* MemTracker::get_thread_recorder(JavaThread* thread) {
+if (shutdown_in_progress()) return NULL;
+MemRecorder* rc;
+if (thread == NULL) {
+rc = _global_recorder;
+} else {
+rc = thread->get_recorder();
+}
+if (rc != NULL && rc->is_full()) {
+enqueue_pending_recorder(rc);
+rc = NULL;
+}
+if (rc == NULL) {
+rc = get_new_or_pooled_instance();
+if (thread == NULL) {
+_global_recorder = rc;
+} else {
+thread->set_recorder(rc);
+}
+}
+return rc;
+}
+/*
+* get a per-thread recorder from pool, or create a new one if
+* there is not one available.
+*/
+MemRecorder* MemTracker::get_new_or_pooled_instance() {
+MemRecorder* cur_head = const_cast<MemRecorder*> (_pooled_recorders);
+if (cur_head == NULL) {
+MemRecorder* rec = new (std::nothrow)MemRecorder();
+if (rec == NULL || rec->out_of_memory()) {
+shutdown(NMT_out_of_memory);
+if (rec != NULL) {
+delete rec;
+rec = NULL;
+}
+}
+return rec;
+} else {
+MemRecorder* next_head = cur_head->next();
+if ((void*)cur_head != Atomic::cmpxchg_ptr((void*)next_head, (void*)&_pooled_recorders,
+(void*)cur_head)) {
+return get_new_or_pooled_instance();
+}
+cur_head->set_next(NULL);
+Atomic::dec(&_pooled_recorder_count);
+debug_only(cur_head->set_generation();)
+return cur_head;
+}
+}
+/*
+* retrieve all recorders in pending queue, and empty the queue
+*/
+MemRecorder* MemTracker::get_pending_recorders() {
+MemRecorder* cur_head = const_cast<MemRecorder*>(_merge_pending_queue);
+MemRecorder* null_ptr = NULL;
+while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)null_ptr, (void*)&_merge_pending_queue,
+(void*)cur_head)) {
+cur_head = const_cast<MemRecorder*>(_merge_pending_queue);
+}
+debug_only(Atomic::store(0, &_pending_recorder_count));
+return cur_head;
+}
+/*
+* release a recorder to recorder pool.
+*/
+void MemTracker::release_thread_recorder(MemRecorder* rec) {
+assert(rec != NULL, "null recorder");
+// we don't want to pool too many recorders
+rec->set_next(NULL);
+if (shutdown_in_progress() || _pooled_recorder_count > _thread_count * 2) {
+delete rec;
+return;
+}
+rec->clear();
+MemRecorder* cur_head = const_cast<MemRecorder*>(_pooled_recorders);
+rec->set_next(cur_head);
+while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)rec, (void*)&_pooled_recorders,
+(void*)cur_head)) {
+cur_head = const_cast<MemRecorder*>(_pooled_recorders);
+rec->set_next(cur_head);
+}
+Atomic::inc(&_pooled_recorder_count);
+}
+/*
+* This is the most important method in whole nmt implementation.
+*
+* Create a memory record.
+* 1. When nmt is in single-threaded bootstrapping mode, no lock is needed as VM
+*    still in single thread mode.
+* 2. For all threads other than JavaThread, ThreadCritical is needed
+*    to write to recorders to global recorder.
+* 3. For JavaThreads that are not longer visible by safepoint, also
+*    need to take ThreadCritical and records are written to global
+*    recorders, since these threads are NOT walked by Threads.do_thread().
+* 4. JavaThreads that are running in native state, have to transition
+*    to VM state before writing to per-thread recorders.
+* 5. JavaThreads that are running in VM state do not need any lock and
+*    records are written to per-thread recorders.
+* 6. For a thread has yet to attach VM 'Thread', they need to take
+*    ThreadCritical to write to global recorder.
+*
+*    Important note:
+*    NO LOCK should be taken inside ThreadCritical lock !!!
+*/
+void MemTracker::create_memory_record(address addr, MEMFLAGS flags,
+size_t size, address pc, Thread* thread) {
+if (!shutdown_in_progress()) {
+// single thread, we just write records direct to global recorder,'
+// with any lock
+if (_state == NMT_bootstrapping_single_thread) {
+assert(_main_thread_tid == os::current_thread_id(), "wrong thread");
+thread = NULL;
+} else {
+if (thread == NULL) {
+// don't use Thread::current(), since it is possible that
+// the calling thread has yet to attach to VM 'Thread',
+// which will result assertion failure
+thread = ThreadLocalStorage::thread();
+}
+}
+if (thread != NULL) {
+if (thread->is_Java_thread() && ((JavaThread*)thread)->is_safepoint_visible()) {
+JavaThread*      java_thread = static_cast<JavaThread*>(thread);
+JavaThreadState  state = java_thread->thread_state();
+if (SafepointSynchronize::safepoint_safe(java_thread, state)) {
+// JavaThreads that are safepoint safe, can run through safepoint,
+// so ThreadCritical is needed to ensure no threads at safepoint create
+// new records while the records are being gathered and the sequence number is changing
+ThreadCritical tc;
+create_record_in_recorder(addr, flags, size, pc, java_thread);
+} else {
+create_record_in_recorder(addr, flags, size, pc, java_thread);
+}
+} else {
+// other threads, such as worker and watcher threads, etc. need to
+// take ThreadCritical to write to global recorder
+ThreadCritical tc;
+create_record_in_recorder(addr, flags, size, pc, NULL);
+}
+} else {
+if (_state == NMT_bootstrapping_single_thread) {
+// single thread, no lock needed
+create_record_in_recorder(addr, flags, size, pc, NULL);
+} else {
+// for thread has yet to attach VM 'Thread', we can not use VM mutex.
+// use native thread critical instead
+ThreadCritical tc;
+create_record_in_recorder(addr, flags, size, pc, NULL);
+}
+}
+}
+}
+// write a record to proper recorder. No lock can be taken from this method
+// down.
+void MemTracker::create_record_in_recorder(address addr, MEMFLAGS flags,
+size_t size, address pc, JavaThread* thread) {
+MemRecorder* rc = get_thread_recorder(thread);
+if (rc != NULL) {
+rc->record(addr, flags, size, pc);
+}
+}
+/**
+* enqueue a recorder to pending queue
+*/
+void MemTracker::enqueue_pending_recorder(MemRecorder* rec) {
+assert(rec != NULL, "null recorder");
+// we are shutting down, so just delete it
+if (shutdown_in_progress()) {
+rec->set_next(NULL);
+delete rec;
+return;
+}
+MemRecorder* cur_head = const_cast<MemRecorder*>(_merge_pending_queue);
+rec->set_next(cur_head);
+while ((void*)cur_head != Atomic::cmpxchg_ptr((void*)rec, (void*)&_merge_pending_queue,
+(void*)cur_head)) {
+cur_head = const_cast<MemRecorder*>(_merge_pending_queue);
+rec->set_next(cur_head);
+}
+debug_only(Atomic::inc(&_pending_recorder_count);)
+}
+/*
+* The method is called at global safepoint
+* during it synchronization process.
+*   1. enqueue all JavaThreads' per-thread recorders
+*   2. enqueue global recorder
+*   3. retrieve all pending recorders
+*   4. reset global sequence number generator
+*   5. call worker's sync
+*/
+#define MAX_SAFEPOINTS_TO_SKIP     128
+#define SAFE_SEQUENCE_THRESHOLD    30
+#define HIGH_GENERATION_THRESHOLD  60
+void MemTracker::sync() {
+assert(_tracking_level > NMT_off, "NMT is not enabled");
+assert(SafepointSynchronize::is_at_safepoint(), "Safepoint required");
+// Some GC tests hit large number of safepoints in short period of time
+// without meaningful activities. We should prevent going to
+// sync point in these cases, which can potentially exhaust generation buffer.
+// Here is the factots to determine if we should go into sync point:
+// 1. not to overflow sequence number
+// 2. if we are in danger to overflow generation buffer
+// 3. how many safepoints we already skipped sync point
+if (_state == NMT_started) {
+// worker thread is not ready, no one can manage generation
+// buffer, so skip this safepoint
+if (_worker_thread == NULL) return;
+if (_sync_point_skip_count < MAX_SAFEPOINTS_TO_SKIP) {
+int per_seq_in_use = SequenceGenerator::peek() * 100 / max_jint;
+int per_gen_in_use = _worker_thread->generations_in_use() * 100 / MAX_GENERATIONS;
+if (per_seq_in_use < SAFE_SEQUENCE_THRESHOLD && per_gen_in_use >= HIGH_GENERATION_THRESHOLD) {
+_sync_point_skip_count ++;
+return;
+}
+}
+_sync_point_skip_count = 0;
+{
+// This method is running at safepoint, with ThreadCritical lock,
+// it should guarantee that NMT is fully sync-ed.
+ThreadCritical tc;
+// walk all JavaThreads to collect recorders
+SyncThreadRecorderClosure stc;
+Threads::threads_do(&stc);
+_thread_count = stc.get_thread_count();
+MemRecorder* pending_recorders = get_pending_recorders();
+if (_global_recorder != NULL) {
+_global_recorder->set_next(pending_recorders);
+pending_recorders = _global_recorder;
+_global_recorder = NULL;
+}
+SequenceGenerator::reset();
+// check _worker_thread with lock to avoid racing condition
+if (_worker_thread != NULL) {
+_worker_thread->at_sync_point(pending_recorders);
+}
+}
+}
+// now, it is the time to shut whole things off
+if (_state == NMT_final_shutdown) {
+// walk all JavaThreads to delete all recorders
+SyncThreadRecorderClosure stc;
+Threads::threads_do(&stc);
+// delete global recorder
+{
+ThreadCritical tc;
+if (_global_recorder != NULL) {
+delete _global_recorder;
+_global_recorder = NULL;
+}
+}
+MemRecorder* pending_recorders = get_pending_recorders();
+if (pending_recorders != NULL) {
+delete pending_recorders;
+}
+// try at a later sync point to ensure MemRecorder instance drops to zero to
+// completely shutdown NMT
+if (MemRecorder::_instance_count == 0) {
+_state = NMT_shutdown;
+_tracking_level = NMT_off;
+}
+}
+}
+/*
+* Start worker thread.
+*/
+bool MemTracker::start_worker() {
+assert(_worker_thread == NULL, "Just Check");
+_worker_thread = new (std::nothrow) MemTrackWorker();
+if (_worker_thread == NULL || _worker_thread->has_error()) {
+shutdown(NMT_initialization);
+return false;
+}
+_worker_thread->start();
+return true;
+}
+/*
+* We need to collect a JavaThread's per-thread recorder
+* before it exits.
+*/
+void MemTracker::thread_exiting(JavaThread* thread) {
+if (is_on()) {
+MemRecorder* rec = thread->get_recorder();
+if (rec != NULL) {
+enqueue_pending_recorder(rec);
+thread->set_recorder(NULL);
+}
+}
+}
+// baseline current memory snapshot
+bool MemTracker::baseline() {
+MutexLockerEx lock(_query_lock, true);
+MemSnapshot* snapshot = get_snapshot();
+if (snapshot != NULL) {
+return _baseline.baseline(*snapshot, false);
+}
+return false;
+}
+// print memory usage from current snapshot
+bool MemTracker::print_memory_usage(BaselineOutputer& out, size_t unit, bool summary_only) {
+MemBaseline  baseline;
+MutexLockerEx lock(_query_lock, true);
+MemSnapshot* snapshot = get_snapshot();
+if (snapshot != NULL && baseline.baseline(*snapshot, summary_only)) {
+BaselineReporter reporter(out, unit);
+reporter.report_baseline(baseline, summary_only);
+return true;
+}
+return false;
+}
+// compare memory usage between current snapshot and baseline
+bool MemTracker::compare_memory_usage(BaselineOutputer& out, size_t unit, bool summary_only) {
+MutexLockerEx lock(_query_lock, true);
+if (_baseline.baselined()) {
+MemBaseline baseline;
+MemSnapshot* snapshot = get_snapshot();
+if (snapshot != NULL && baseline.baseline(*snapshot, summary_only)) {
+BaselineReporter reporter(out, unit);
+reporter.diff_baselines(baseline, _baseline, summary_only);
+return true;
+}
+}
+return false;
+}
+#ifndef PRODUCT
+void MemTracker::walk_stack(int toSkip, char* buf, int len) {
+int cur_len = 0;
+char tmp[1024];
+address pc;
+while (cur_len < len) {
+pc = os::get_caller_pc(toSkip + 1);
+if (pc != NULL && os::dll_address_to_function_name(pc, tmp, sizeof(tmp), NULL)) {
+jio_snprintf(&buf[cur_len], (len - cur_len), "%s\n", tmp);
+cur_len = (int)strlen(buf);
+} else {
+buf[cur_len] = '\0';
+break;
+}
+toSkip ++;
+}
+}
+void MemTracker::print_tracker_stats(outputStream* st) {
+st->print_cr("\nMemory Tracker Stats:");
+st->print_cr("\tMax sequence number = %d", SequenceGenerator::max_seq_num());
+st->print_cr("\tthead count = %d", _thread_count);
+st->print_cr("\tArena instance = %d", Arena::_instance_count);
+st->print_cr("\tpooled recorder count = %d", _pooled_recorder_count);
+st->print_cr("\tqueued recorder count = %d", _pending_recorder_count);
+st->print_cr("\tmemory recorder instance count = %d", MemRecorder::_instance_count);
+if (_worker_thread != NULL) {
+st->print_cr("\tWorker thread:");
+st->print_cr("\t\tSync point count = %d", _worker_thread->_sync_point_count);
+st->print_cr("\t\tpending recorder count = %d", _worker_thread->count_pending_recorders());
+st->print_cr("\t\tmerge count = %d", _worker_thread->_merge_count);
+} else {
+st->print_cr("\tWorker thread is not started");
+}
+st->print_cr(" ");
+if (_snapshot != NULL) {
+_snapshot->print_snapshot_stats(st);
+} else {
+st->print_cr("No snapshot");
+}
+}
+#endif

Mercurial > hg > truffle

comparison src/share/vm/services/memTracker.cpp @ 6275:957c266d8bc5