--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/leakprofiler/sampling/objectSampler.cpp	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,193 @@
+/*
+ * Copyright (c) 2014, 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 "oops/oop.inline.hpp"
+#include "runtime/thread.hpp"
+#include "logging/log.hpp"
+
+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),
+  _tryLock(0),
+  _dead_samples(false) {}
+
+ObjectSampler::~ObjectSampler() {
+  delete _priority_queue;
+  _priority_queue = NULL;
+  delete _list;
+  _list = NULL;
+}
+
+void ObjectSampler::add(HeapWord* obj, size_t allocated, JavaThread* thread) {
+  assert(thread != NULL, "invariant");
+  const traceid thread_id = thread->threadObj() != NULL ? thread->jfr_thread_local()->thread_id() : 0;
+  if (thread_id == 0) {
+    return;
+  }
+  assert(thread_id != 0, "invariant");
+
+  if (!thread->jfr_thread_local()->has_thread_checkpoint()) {
+    JfrCheckpointManager::create_thread_checkpoint(thread);
+    assert(thread->jfr_thread_local()->has_thread_checkpoint(), "invariant");
+  }
+
+  traceid stack_trace_id = 0;
+  unsigned int stack_trace_hash = 0;
+  if (JfrEventSetting::has_stacktrace(EventOldObjectSample::eventId)) {
+    stack_trace_id = JfrStackTraceRepository::record(thread, 0, &stack_trace_hash);
+    thread->jfr_thread_local()->set_cached_stack_trace_id(stack_trace_id, stack_trace_hash);
+  }
+
+  const JfrTicks allocation_time = JfrTicks::now();
+
+  JfrTryLock tryLock(&_tryLock);
+  if (!tryLock.has_lock()) {
+    log_trace(jfr, oldobject, sampling)("Skipping old object sample due to lock contention");
+    return;
+  }
+
+  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");
+  assert(thread_id != 0, "invariant");
+  sample->set_thread_id(thread_id);
+  sample->set_thread_checkpoint(thread->jfr_thread_local()->thread_checkpoint());
+
+  if (stack_trace_id != 0) {
+    sample->set_stack_trace_id(stack_trace_id);
+    sample->set_stack_trace_hash(stack_trace_hash);
+  }
+
+  sample->set_span(allocated);
+  sample->set_object((oop)obj);
+  sample->set_allocated(allocated);
+  sample->set_allocation_time(allocation_time);
+  _priority_queue->push(sample);
+}
+
+const ObjectSample* ObjectSampler::last() const {
+  return _list->last();
+}
+
+const ObjectSample* ObjectSampler::last_resolved() const {
+  return _list->last_resolved();
+}
+
+void ObjectSampler::set_last_resolved(const ObjectSample* sample) {
+  _list->set_last_resolved(sample);
+}
+
+void ObjectSampler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) {
+  ObjectSample* current = _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();
+        _dead_samples = true;
+      }
+    }
+    current = next;
+  }
+  _last_sweep = JfrTicks::now();
+}
+
+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::scavenge() {
+  ObjectSample* current = _list->last();
+  while (current != NULL) {
+    ObjectSample* next = current->next();
+    if (current->is_dead()) {
+      remove_dead(current);
+    }
+    current = next;
+  }
+  _dead_samples = false;
+}
+
+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;
+}