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/*
* 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/threadCritical.hpp"
#include "services/memTracker.hpp"
#include "services/memTrackWorker.hpp"
#include "utilities/decoder.hpp"
#include "utilities/vmError.hpp"
void GenerationData::reset() {
_number_of_classes = 0;
while (_recorder_list != NULL) {
MemRecorder* tmp = _recorder_list;
_recorder_list = _recorder_list->next();
MemTracker::release_thread_recorder(tmp);
}
}
MemTrackWorker::MemTrackWorker() {
// create thread uses cgc thread type for now. We should revisit
// the option, or create new thread type.
_has_error = !os::create_thread(this, os::cgc_thread);
set_name("MemTrackWorker", 0);
// initial generation circuit buffer
if (!has_error()) {
_head = _tail = 0;
for(int index = 0; index < MAX_GENERATIONS; index ++) {
::new ((void*)&_gen[index]) GenerationData();
}
}
NOT_PRODUCT(_sync_point_count = 0;)
NOT_PRODUCT(_merge_count = 0;)
NOT_PRODUCT(_last_gen_in_use = 0;)
}
MemTrackWorker::~MemTrackWorker() {
for (int index = 0; index < MAX_GENERATIONS; index ++) {
_gen[index].reset();
}
}
void* MemTrackWorker::operator new(size_t size) {
assert(false, "use nothrow version");
return NULL;
}
void* MemTrackWorker::operator new(size_t size, const std::nothrow_t& nothrow_constant) {
return allocate(size, false, mtNMT);
}
void MemTrackWorker::start() {
os::start_thread(this);
}
/*
* Native memory tracking worker thread loop:
* 1. merge one generation of memory recorders to staging area
* 2. promote staging data to memory snapshot
*
* This thread can run through safepoint.
*/
void MemTrackWorker::run() {
assert(MemTracker::is_on(), "native memory tracking is off");
this->initialize_thread_local_storage();
this->record_stack_base_and_size();
MemSnapshot* snapshot = MemTracker::get_snapshot();
assert(snapshot != NULL, "Worker should not be started");
MemRecorder* rec;
unsigned long processing_generation = 0;
bool worker_idle = false;
while (!MemTracker::shutdown_in_progress()) {
NOT_PRODUCT(_last_gen_in_use = generations_in_use();)
{
// take a recorder from earliest generation in buffer
ThreadCritical tc;
rec = _gen[_head].next_recorder();
}
if (rec != NULL) {
if (rec->get_generation() != processing_generation || worker_idle) {
processing_generation = rec->get_generation();
worker_idle = false;
MemTracker::set_current_processing_generation(processing_generation);
}
// merge the recorder into staging area
if (!snapshot->merge(rec)) {
MemTracker::shutdown(MemTracker::NMT_out_of_memory);
} else {
NOT_PRODUCT(_merge_count ++;)
}
MemTracker::release_thread_recorder(rec);
} else {
// no more recorder to merge, promote staging area
// to snapshot
if (_head != _tail) {
long number_of_classes;
{
ThreadCritical tc;
if (_gen[_head].has_more_recorder() || _head == _tail) {
continue;
}
number_of_classes = _gen[_head].number_of_classes();
_gen[_head].reset();
// done with this generation, increment _head pointer
_head = (_head + 1) % MAX_GENERATIONS;
}
// promote this generation data to snapshot
if (!snapshot->promote(number_of_classes)) {
// failed to promote, means out of memory
MemTracker::shutdown(MemTracker::NMT_out_of_memory);
}
} else {
// worker thread is idle
worker_idle = true;
MemTracker::report_worker_idle();
snapshot->wait(1000);
ThreadCritical tc;
// check if more data arrived
if (!_gen[_head].has_more_recorder()) {
_gen[_head].add_recorders(MemTracker::get_pending_recorders());
}
}
}
}
assert(MemTracker::shutdown_in_progress(), "just check");
// transits to final shutdown
MemTracker::final_shutdown();
}
// at synchronization point, where 'safepoint visible' Java threads are blocked
// at a safepoint, and the rest of threads are blocked on ThreadCritical lock.
// The caller MemTracker::sync() already takes ThreadCritical before calling this
// method.
//
// Following tasks are performed:
// 1. add all recorders in pending queue to current generation
// 2. increase generation
void MemTrackWorker::at_sync_point(MemRecorder* rec, int number_of_classes) {
NOT_PRODUCT(_sync_point_count ++;)
assert(count_recorder(rec) <= MemRecorder::_instance_count,
"pending queue has infinite loop");
bool out_of_generation_buffer = false;
// check shutdown state inside ThreadCritical
if (MemTracker::shutdown_in_progress()) return;
_gen[_tail].set_number_of_classes(number_of_classes);
// append the recorders to the end of the generation
_gen[_tail].add_recorders(rec);
assert(count_recorder(_gen[_tail].peek()) <= MemRecorder::_instance_count,
"after add to current generation has infinite loop");
// we have collected all recorders for this generation. If there is data,
// we need to increment _tail to start a new generation.
if (_gen[_tail].has_more_recorder() || _head == _tail) {
_tail = (_tail + 1) % MAX_GENERATIONS;
out_of_generation_buffer = (_tail == _head);
}
if (out_of_generation_buffer) {
MemTracker::shutdown(MemTracker::NMT_out_of_generation);
}
}
#ifndef PRODUCT
int MemTrackWorker::count_recorder(const MemRecorder* head) {
int count = 0;
while(head != NULL) {
count ++;
head = head->next();
}
return count;
}
int MemTrackWorker::count_pending_recorders() const {
int count = 0;
for (int index = 0; index < MAX_GENERATIONS; index ++) {
MemRecorder* head = _gen[index].peek();
if (head != NULL) {
count += count_recorder(head);
}
}
return count;
}
#endif
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