jdk8-mips64-public/hotspot: src/share/vm/jfr/leakprofiler/sampling/objectSampler.cpp@8e875c964f41 (annotated)

src/share/vm/jfr/leakprofiler/sampling/objectSampler.cpp@8e875c964f41 (annotated)

src/share/vm/jfr/leakprofiler/sampling/objectSampler.cpp

Wed, 09 Oct 2019 16:11:58 +0800

author: ddong
date: Wed, 09 Oct 2019 16:11:58 +0800
changeset 9885: 8e875c964f41
parent 9867: 150ab470bf7f
permissions: -rw-r--r--

8214542: JFR: Old Object Sample event slow on a deep heap in debug builds
Reviewed-by: egahlin, rwestberg

 /*
  * Copyright (c) 2017, 2018, 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 "jfr/jfrEvents.hpp"
 #include "jfr/leakprofiler/sampling/objectSample.hpp"
 #include "jfr/leakprofiler/sampling/objectSampler.hpp"
 #include "jfr/leakprofiler/sampling/sampleList.hpp"
 #include "jfr/leakprofiler/sampling/samplePriorityQueue.hpp"
 #include "jfr/recorder/jfrEventSetting.inline.hpp"
 #include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
 #include "jfr/recorder/stacktrace/jfrStackTraceRepository.hpp"
 #include "jfr/support/jfrThreadLocal.hpp"
 #include "jfr/utilities/jfrTryLock.hpp"
 #include "memory/universe.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/atomic.hpp"
 #include "runtime/orderAccess.hpp"
 #include "runtime/safepoint.hpp"
 #include "runtime/thread.hpp"
 static ObjectSampler* _instance = NULL;
 static ObjectSampler& instance() {
   assert(_instance != NULL, "invariant");
   return *_instance;
 }
 ObjectSampler::ObjectSampler(size_t size) :
   _priority_queue(new SamplePriorityQueue(size)),
   _list(new SampleList(size)),
   _last_sweep(JfrTicks::now()),
   _total_allocated(0),
   _threshold(0),
   _size(size),
   _dead_samples(false) {}
 ObjectSampler::~ObjectSampler() {
   delete _priority_queue;
   _priority_queue = NULL;
   delete _list;
   _list = NULL;
 }
 bool ObjectSampler::create(size_t size) {
   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
   assert(_instance == NULL, "invariant");
   _instance = new ObjectSampler(size);
   return _instance != NULL;
 }
 bool ObjectSampler::is_created() {
   return _instance != NULL;
 }
 ObjectSampler* ObjectSampler::sampler() {
   assert(is_created(), "invariant");
   return _instance;
 }
 void ObjectSampler::destroy() {
   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
   if (_instance != NULL) {
     ObjectSampler* const sampler = _instance;
     _instance = NULL;
     delete sampler;
   }
 }
 static volatile int _lock = 0;
 ObjectSampler* ObjectSampler::acquire() {
   assert(is_created(), "invariant");
   while (Atomic::cmpxchg(1, &_lock, 0) == 1) {}
   return _instance;
 }
 void ObjectSampler::release() {
   assert(is_created(), "invariant");
   OrderAccess::fence();
   _lock = 0;
 }
 static traceid get_thread_id(JavaThread* thread) {
   assert(thread != NULL, "invariant");
   if (thread->threadObj() == NULL) {
     return 0;
   }
   const JfrThreadLocal* const tl = thread->jfr_thread_local();
   assert(tl != NULL, "invariant");
   if (!tl->has_thread_checkpoint()) {
     JfrCheckpointManager::create_thread_checkpoint(thread);
   }
   assert(tl->has_thread_checkpoint(), "invariant");
   return tl->thread_id();
 }
 // Populates the thread local stack frames, but does not add them
 // to the stacktrace repository (...yet, see stacktrace_id() below)
 //
 void ObjectSampler::fill_stacktrace(JfrStackTrace* stacktrace, JavaThread* thread) {
   assert(stacktrace != NULL, "invariant");
   assert(thread != NULL, "invariant");
   if (JfrEventSetting::has_stacktrace(EventOldObjectSample::eventId)) {
     JfrStackTraceRepository::fill_stacktrace_for(thread, stacktrace, 0);
   }
 }
 // We were successful in acquiring the try lock and have been selected for adding a sample.
 // Go ahead with installing our previously taken stacktrace into the stacktrace repository.
 //
 traceid ObjectSampler::stacktrace_id(const JfrStackTrace* stacktrace, JavaThread* thread) {
   assert(stacktrace != NULL, "invariant");
   assert(stacktrace->hash() != 0, "invariant");
   const traceid stacktrace_id = JfrStackTraceRepository::add(stacktrace, thread);
   thread->jfr_thread_local()->set_cached_stack_trace_id(stacktrace_id, stacktrace->hash());
   return stacktrace_id;
 }
 void ObjectSampler::sample(HeapWord* obj, size_t allocated, JavaThread* thread) {
   assert(thread != NULL, "invariant");
   assert(is_created(), "invariant");
   const traceid thread_id = get_thread_id(thread);
   if (thread_id == 0) {
     return;
   }
   const JfrThreadLocal* const tl = thread->jfr_thread_local();
   JfrStackTrace stacktrace(tl->stackframes(), tl->stackdepth());
   fill_stacktrace(&stacktrace, thread);
   // try enter critical section
   JfrTryLock tryLock(&_lock);
   if (!tryLock.has_lock()) {
     if (LogJFR && Verbose) tty->print_cr("Skipping old object sample due to lock contention");
     return;
   }
   instance().add(obj, allocated, thread_id, &stacktrace, thread);
 }
 void ObjectSampler::add(HeapWord* obj, size_t allocated, traceid thread_id, JfrStackTrace* stacktrace, JavaThread* thread) {
   assert(stacktrace != NULL, "invariant");
   assert(thread_id != 0, "invariant");
   assert(thread != NULL, "invariant");
   assert(thread->jfr_thread_local()->has_thread_checkpoint(), "invariant");
   if (_dead_samples) {
     scavenge();
     assert(!_dead_samples, "invariant");
   }
   _total_allocated += allocated;
   const size_t span = _total_allocated - _priority_queue->total();
   ObjectSample* sample;
   if ((size_t)_priority_queue->count() == _size) {
     assert(_list->count() == _size, "invariant");
     const ObjectSample* peek = _priority_queue->peek();
     if (peek->span() > span) {
       // quick reject, will not fit
       return;
     }
     sample = _list->reuse(_priority_queue->pop());
   } else {
     sample = _list->get();
   }
   assert(sample != NULL, "invariant");
   sample->set_thread_id(thread_id);
   sample->set_thread_checkpoint(thread->jfr_thread_local()->thread_checkpoint());
   const unsigned int stacktrace_hash = stacktrace->hash();
   if (stacktrace_hash != 0) {
     sample->set_stack_trace_id(stacktrace_id(stacktrace, thread));
     sample->set_stack_trace_hash(stacktrace_hash);
   }
   sample->set_span(allocated);
   sample->set_object((oop)obj);
   sample->set_allocated(allocated);
   sample->set_allocation_time(JfrTicks::now());
   sample->set_heap_used_at_last_gc(Universe::get_heap_used_at_last_gc());
   _priority_queue->push(sample);
 }
 void ObjectSampler::scavenge() {
   ObjectSample* current = _list->last();
   while (current != NULL) {
     ObjectSample* next = current->next();
     if (current->is_dead()) {
       remove_dead(current);
     }
     current = next;
   }
   _dead_samples = false;
 }
 void ObjectSampler::remove_dead(ObjectSample* sample) {
   assert(sample != NULL, "invariant");
   assert(sample->is_dead(), "invariant");
   ObjectSample* const previous = sample->prev();
   // push span on to previous
   if (previous != NULL) {
     _priority_queue->remove(previous);
     previous->add_span(sample->span());
     _priority_queue->push(previous);
   }
   _priority_queue->remove(sample);
   _list->release(sample);
 }
 void ObjectSampler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) {
   assert(is_created(), "invariant");
   assert(SafepointSynchronize::is_at_safepoint(), "invariant");
   ObjectSampler& sampler = instance();
   ObjectSample* current = sampler._list->last();
   while (current != NULL) {
     ObjectSample* next = current->next();
     if (!current->is_dead()) {
       if (is_alive->do_object_b(current->object())) {
         // The weakly referenced object is alive, update pointer
         f->do_oop(const_cast<oop*>(current->object_addr()));
       } else {
         current->set_dead();
         sampler._dead_samples = true;
       }
     }
     current = next;
   }
   sampler._last_sweep = JfrTicks::now();
 }
 const ObjectSample* ObjectSampler::last() const {
   return _list->last();
 }
 const ObjectSample* ObjectSampler::first() const {
   return _list->first();
 }
 const ObjectSample* ObjectSampler::last_resolved() const {
   return _list->last_resolved();
 }
 void ObjectSampler::set_last_resolved(const ObjectSample* sample) {
   _list->set_last_resolved(sample);
 }
 int ObjectSampler::item_count() const {
   return _priority_queue->count();
 }
 const ObjectSample* ObjectSampler::item_at(int index) const {
   return _priority_queue->item_at(index);
 }
 ObjectSample* ObjectSampler::item_at(int index) {
   return const_cast<ObjectSample*>(
     const_cast<const ObjectSampler*>(this)->item_at(index)
                                   );
 }
 const JfrTicks& ObjectSampler::last_sweep() const {
   return _last_sweep;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/jfr/leakprofiler/sampling/objectSampler.cpp@8e875c964f41 (annotated)

src/share/vm/jfr/leakprofiler/sampling/objectSampler.cpp