apetushkov@9858: /*
ddong@9885:  * Copyright (c) 2017, 2018, Oracle and/or its affiliates. All rights reserved.
apetushkov@9858:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
apetushkov@9858:  *
apetushkov@9858:  * This code is free software; you can redistribute it and/or modify it
apetushkov@9858:  * under the terms of the GNU General Public License version 2 only, as
apetushkov@9858:  * published by the Free Software Foundation.
apetushkov@9858:  *
apetushkov@9858:  * This code is distributed in the hope that it will be useful, but WITHOUT
apetushkov@9858:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
apetushkov@9858:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
apetushkov@9858:  * version 2 for more details (a copy is included in the LICENSE file that
apetushkov@9858:  * accompanied this code).
apetushkov@9858:  *
apetushkov@9858:  * You should have received a copy of the GNU General Public License version
apetushkov@9858:  * 2 along with this work; if not, write to the Free Software Foundation,
apetushkov@9858:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
apetushkov@9858:  *
apetushkov@9858:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
apetushkov@9858:  * or visit www.oracle.com if you need additional information or have any
apetushkov@9858:  * questions.
apetushkov@9858:  *
apetushkov@9858:  */
apetushkov@9858: #include "precompiled.hpp"
apetushkov@9858: #include "jfr/jfrEvents.hpp"
apetushkov@9858: #include "jfr/leakprofiler/sampling/objectSample.hpp"
apetushkov@9858: #include "jfr/leakprofiler/sampling/objectSampler.hpp"
apetushkov@9858: #include "jfr/leakprofiler/sampling/sampleList.hpp"
apetushkov@9858: #include "jfr/leakprofiler/sampling/samplePriorityQueue.hpp"
apetushkov@9858: #include "jfr/recorder/jfrEventSetting.inline.hpp"
apetushkov@9858: #include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
apetushkov@9858: #include "jfr/recorder/stacktrace/jfrStackTraceRepository.hpp"
apetushkov@9858: #include "jfr/support/jfrThreadLocal.hpp"
apetushkov@9858: #include "jfr/utilities/jfrTryLock.hpp"
apetushkov@9858: #include "memory/universe.hpp"
apetushkov@9858: #include "oops/oop.inline.hpp"
ddong@9885: #include "runtime/atomic.hpp"
ddong@9885: #include "runtime/orderAccess.hpp"
ddong@9885: #include "runtime/safepoint.hpp"
apetushkov@9858: #include "runtime/thread.hpp"
apetushkov@9858: 
ddong@9885: static ObjectSampler* _instance = NULL;
ddong@9885: 
ddong@9885: static ObjectSampler& instance() {
ddong@9885:   assert(_instance != NULL, "invariant");
ddong@9885:   return *_instance;
ddong@9885: }
ddong@9885: 
apetushkov@9858: ObjectSampler::ObjectSampler(size_t size) :
apetushkov@9858:   _priority_queue(new SamplePriorityQueue(size)),
apetushkov@9858:   _list(new SampleList(size)),
apetushkov@9858:   _last_sweep(JfrTicks::now()),
apetushkov@9858:   _total_allocated(0),
apetushkov@9858:   _threshold(0),
apetushkov@9858:   _size(size),
apetushkov@9858:   _dead_samples(false) {}
apetushkov@9858: 
apetushkov@9858: ObjectSampler::~ObjectSampler() {
apetushkov@9858:   delete _priority_queue;
apetushkov@9858:   _priority_queue = NULL;
apetushkov@9858:   delete _list;
apetushkov@9858:   _list = NULL;
apetushkov@9858: }
apetushkov@9858: 
ddong@9885: bool ObjectSampler::create(size_t size) {
ddong@9885:   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
ddong@9885:   assert(_instance == NULL, "invariant");
ddong@9885:   _instance = new ObjectSampler(size);
ddong@9885:   return _instance != NULL;
ddong@9885: }
ddong@9885: 
ddong@9885: bool ObjectSampler::is_created() {
ddong@9885:   return _instance != NULL;
ddong@9885: }
ddong@9885: 
ddong@9885: ObjectSampler* ObjectSampler::sampler() {
ddong@9885:   assert(is_created(), "invariant");
ddong@9885:   return _instance;
ddong@9885: }
ddong@9885: 
ddong@9885: void ObjectSampler::destroy() {
ddong@9885:   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
ddong@9885:   if (_instance != NULL) {
ddong@9885:     ObjectSampler* const sampler = _instance;
ddong@9885:     _instance = NULL;
ddong@9885:     delete sampler;
ddong@9885:   }
ddong@9885: }
ddong@9885: 
ddong@9885: static volatile int _lock = 0;
ddong@9885: 
ddong@9885: ObjectSampler* ObjectSampler::acquire() {
ddong@9885:   assert(is_created(), "invariant");
ddong@9885:   while (Atomic::cmpxchg(1, &_lock, 0) == 1) {}
ddong@9885:   return _instance;
ddong@9885: }
ddong@9885: 
ddong@9885: void ObjectSampler::release() {
ddong@9885:   assert(is_created(), "invariant");
ddong@9885:   OrderAccess::fence();
ddong@9885:   _lock = 0;
ddong@9885: }
ddong@9885: 
ddong@9885: static traceid get_thread_id(JavaThread* thread) {
apetushkov@9858:   assert(thread != NULL, "invariant");
ddong@9885:   if (thread->threadObj() == NULL) {
ddong@9885:     return 0;
ddong@9885:   }
ddong@9885:   const JfrThreadLocal* const tl = thread->jfr_thread_local();
ddong@9885:   assert(tl != NULL, "invariant");
ddong@9885:   if (!tl->has_thread_checkpoint()) {
ddong@9885:     JfrCheckpointManager::create_thread_checkpoint(thread);
ddong@9885:   }
ddong@9885:   assert(tl->has_thread_checkpoint(), "invariant");
ddong@9885:   return tl->thread_id();
ddong@9885: }
ddong@9885: 
ddong@9885: // Populates the thread local stack frames, but does not add them
ddong@9885: // to the stacktrace repository (...yet, see stacktrace_id() below)
ddong@9885: //
ddong@9885: void ObjectSampler::fill_stacktrace(JfrStackTrace* stacktrace, JavaThread* thread) {
ddong@9885:   assert(stacktrace != NULL, "invariant");
ddong@9885:   assert(thread != NULL, "invariant");
ddong@9885:   if (JfrEventSetting::has_stacktrace(EventOldObjectSample::eventId)) {
ddong@9885:     JfrStackTraceRepository::fill_stacktrace_for(thread, stacktrace, 0);
ddong@9885:   }
ddong@9885: }
ddong@9885: 
ddong@9885: // We were successful in acquiring the try lock and have been selected for adding a sample.
ddong@9885: // Go ahead with installing our previously taken stacktrace into the stacktrace repository.
ddong@9885: //
ddong@9885: traceid ObjectSampler::stacktrace_id(const JfrStackTrace* stacktrace, JavaThread* thread) {
ddong@9885:   assert(stacktrace != NULL, "invariant");
ddong@9885:   assert(stacktrace->hash() != 0, "invariant");
ddong@9885:   const traceid stacktrace_id = JfrStackTraceRepository::add(stacktrace, thread);
ddong@9885:   thread->jfr_thread_local()->set_cached_stack_trace_id(stacktrace_id, stacktrace->hash());
ddong@9885:   return stacktrace_id;
ddong@9885: }
ddong@9885: 
ddong@9885: void ObjectSampler::sample(HeapWord* obj, size_t allocated, JavaThread* thread) {
ddong@9885:   assert(thread != NULL, "invariant");
ddong@9885:   assert(is_created(), "invariant");
ddong@9885: 
ddong@9885:   const traceid thread_id = get_thread_id(thread);
apetushkov@9858:   if (thread_id == 0) {
apetushkov@9858:     return;
apetushkov@9858:   }
ddong@9885:   const JfrThreadLocal* const tl = thread->jfr_thread_local();
ddong@9885:   JfrStackTrace stacktrace(tl->stackframes(), tl->stackdepth());
ddong@9885:   fill_stacktrace(&stacktrace, thread);
apetushkov@9858: 
ddong@9885:   // try enter critical section
ddong@9885:   JfrTryLock tryLock(&_lock);
apetushkov@9858:   if (!tryLock.has_lock()) {
apetushkov@9858:     if (LogJFR && Verbose) tty->print_cr("Skipping old object sample due to lock contention");
apetushkov@9858:     return;
apetushkov@9858:   }
apetushkov@9858: 
ddong@9885:   instance().add(obj, allocated, thread_id, &stacktrace, thread);
ddong@9885: }
ddong@9885: 
ddong@9885: void ObjectSampler::add(HeapWord* obj, size_t allocated, traceid thread_id, JfrStackTrace* stacktrace, JavaThread* thread) {
ddong@9885:   assert(stacktrace != NULL, "invariant");
ddong@9885:   assert(thread_id != 0, "invariant");
ddong@9885:   assert(thread != NULL, "invariant");
ddong@9885:   assert(thread->jfr_thread_local()->has_thread_checkpoint(), "invariant");
ddong@9885: 
apetushkov@9858:   if (_dead_samples) {
apetushkov@9858:     scavenge();
apetushkov@9858:     assert(!_dead_samples, "invariant");
apetushkov@9858:   }
apetushkov@9858: 
apetushkov@9858:   _total_allocated += allocated;
apetushkov@9858:   const size_t span = _total_allocated - _priority_queue->total();
apetushkov@9858:   ObjectSample* sample;
apetushkov@9858:   if ((size_t)_priority_queue->count() == _size) {
apetushkov@9858:     assert(_list->count() == _size, "invariant");
apetushkov@9858:     const ObjectSample* peek = _priority_queue->peek();
apetushkov@9858:     if (peek->span() > span) {
apetushkov@9858:       // quick reject, will not fit
apetushkov@9858:       return;
apetushkov@9858:     }
apetushkov@9858:     sample = _list->reuse(_priority_queue->pop());
apetushkov@9858:   } else {
apetushkov@9858:     sample = _list->get();
apetushkov@9858:   }
apetushkov@9858: 
apetushkov@9858:   assert(sample != NULL, "invariant");
apetushkov@9858:   sample->set_thread_id(thread_id);
apetushkov@9858:   sample->set_thread_checkpoint(thread->jfr_thread_local()->thread_checkpoint());
apetushkov@9858: 
ddong@9885:   const unsigned int stacktrace_hash = stacktrace->hash();
ddong@9885:   if (stacktrace_hash != 0) {
ddong@9885:     sample->set_stack_trace_id(stacktrace_id(stacktrace, thread));
ddong@9885:     sample->set_stack_trace_hash(stacktrace_hash);
apetushkov@9858:   }
apetushkov@9858: 
apetushkov@9858:   sample->set_span(allocated);
apetushkov@9858:   sample->set_object((oop)obj);
apetushkov@9858:   sample->set_allocated(allocated);
apetushkov@9858:   sample->set_allocation_time(JfrTicks::now());
apetushkov@9858:   sample->set_heap_used_at_last_gc(Universe::get_heap_used_at_last_gc());
apetushkov@9858:   _priority_queue->push(sample);
apetushkov@9858: }
apetushkov@9858: 
ddong@9885: void ObjectSampler::scavenge() {
ddong@9885:   ObjectSample* current = _list->last();
ddong@9885:   while (current != NULL) {
ddong@9885:     ObjectSample* next = current->next();
ddong@9885:     if (current->is_dead()) {
ddong@9885:       remove_dead(current);
ddong@9885:     }
ddong@9885:     current = next;
ddong@9885:   }
ddong@9885:   _dead_samples = false;
ddong@9885: }
ddong@9885: 
ddong@9885: void ObjectSampler::remove_dead(ObjectSample* sample) {
ddong@9885:   assert(sample != NULL, "invariant");
ddong@9885:   assert(sample->is_dead(), "invariant");
ddong@9885:   ObjectSample* const previous = sample->prev();
ddong@9885:   // push span on to previous
ddong@9885:   if (previous != NULL) {
ddong@9885:     _priority_queue->remove(previous);
ddong@9885:     previous->add_span(sample->span());
ddong@9885:     _priority_queue->push(previous);
ddong@9885:   }
ddong@9885:   _priority_queue->remove(sample);
ddong@9885:   _list->release(sample);
ddong@9885: }
ddong@9885: 
ddong@9885: void ObjectSampler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) {
ddong@9885:   assert(is_created(), "invariant");
ddong@9885:   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
ddong@9885:   ObjectSampler& sampler = instance();
ddong@9885:   ObjectSample* current = sampler._list->last();
ddong@9885:   while (current != NULL) {
ddong@9885:     ObjectSample* next = current->next();
ddong@9885:     if (!current->is_dead()) {
ddong@9885:       if (is_alive->do_object_b(current->object())) {
ddong@9885:         // The weakly referenced object is alive, update pointer
ddong@9885:         f->do_oop(const_cast<oop*>(current->object_addr()));
ddong@9885:       } else {
ddong@9885:         current->set_dead();
ddong@9885:         sampler._dead_samples = true;
ddong@9885:       }
ddong@9885:     }
ddong@9885:     current = next;
ddong@9885:   }
ddong@9885:   sampler._last_sweep = JfrTicks::now();
ddong@9885: }
ddong@9885: 
apetushkov@9858: const ObjectSample* ObjectSampler::last() const {
apetushkov@9858:   return _list->last();
apetushkov@9858: }
apetushkov@9858: 
egahlin@9867: const ObjectSample* ObjectSampler::first() const {
egahlin@9867:   return _list->first();
egahlin@9867: }
egahlin@9867: 
apetushkov@9858: const ObjectSample* ObjectSampler::last_resolved() const {
apetushkov@9858:   return _list->last_resolved();
apetushkov@9858: }
apetushkov@9858: 
apetushkov@9858: void ObjectSampler::set_last_resolved(const ObjectSample* sample) {
apetushkov@9858:   _list->set_last_resolved(sample);
apetushkov@9858: }
apetushkov@9858: 
apetushkov@9858: int ObjectSampler::item_count() const {
apetushkov@9858:   return _priority_queue->count();
apetushkov@9858: }
apetushkov@9858: 
apetushkov@9858: const ObjectSample* ObjectSampler::item_at(int index) const {
apetushkov@9858:   return _priority_queue->item_at(index);
apetushkov@9858: }
apetushkov@9858: 
apetushkov@9858: ObjectSample* ObjectSampler::item_at(int index) {
apetushkov@9858:   return const_cast<ObjectSample*>(
apetushkov@9858:     const_cast<const ObjectSampler*>(this)->item_at(index)
ddong@9885:                                   );
apetushkov@9858: }
apetushkov@9858: 
apetushkov@9858: const JfrTicks& ObjectSampler::last_sweep() const {
apetushkov@9858:   return _last_sweep;
apetushkov@9858: }