1 /*
2 * Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24 #include "precompiled.hpp"
25 #include "jfr/jfrEvents.hpp"
26 #include "jfr/leakprofiler/sampling/objectSample.hpp"
27 #include "jfr/leakprofiler/sampling/objectSampler.hpp"
28 #include "jfr/leakprofiler/sampling/sampleList.hpp"
29 #include "jfr/leakprofiler/sampling/samplePriorityQueue.hpp"
30 #include "jfr/recorder/jfrEventSetting.inline.hpp"
31 #include "jfr/recorder/checkpoint/jfrCheckpointManager.hpp"
32 #include "jfr/recorder/stacktrace/jfrStackTraceRepository.hpp"
33 #include "jfr/support/jfrThreadLocal.hpp"
34 #include "jfr/utilities/jfrTryLock.hpp"
35 #include "memory/universe.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "runtime/thread.hpp"
38
39 ObjectSampler::ObjectSampler(size_t size) :
40 _priority_queue(new SamplePriorityQueue(size)),
41 _list(new SampleList(size)),
42 _last_sweep(JfrTicks::now()),
43 _total_allocated(0),
44 _threshold(0),
45 _size(size),
46 _tryLock(0),
47 _dead_samples(false) {}
48
49 ObjectSampler::~ObjectSampler() {
50 delete _priority_queue;
51 _priority_queue = NULL;
52 delete _list;
53 _list = NULL;
54 }
55
56 void ObjectSampler::add(HeapWord* obj, size_t allocated, JavaThread* thread) {
57 assert(thread != NULL, "invariant");
58 const traceid thread_id = thread->threadObj() != NULL ? thread->jfr_thread_local()->thread_id() : 0;
59 if (thread_id == 0) {
60 return;
61 }
62 assert(thread_id != 0, "invariant");
63
64 if (!thread->jfr_thread_local()->has_thread_checkpoint()) {
65 JfrCheckpointManager::create_thread_checkpoint(thread);
66 assert(thread->jfr_thread_local()->has_thread_checkpoint(), "invariant");
67 }
68
69 traceid stack_trace_id = 0;
70 unsigned int stack_trace_hash = 0;
71 if (JfrEventSetting::has_stacktrace(EventOldObjectSample::eventId)) {
72 stack_trace_id = JfrStackTraceRepository::record(thread, 0, &stack_trace_hash);
73 thread->jfr_thread_local()->set_cached_stack_trace_id(stack_trace_id, stack_trace_hash);
74 }
75
76 JfrTryLock tryLock(&_tryLock);
77 if (!tryLock.has_lock()) {
78 if (LogJFR && Verbose) tty->print_cr("Skipping old object sample due to lock contention");
79 return;
80 }
81
82 if (_dead_samples) {
83 scavenge();
84 assert(!_dead_samples, "invariant");
85 }
86
87 _total_allocated += allocated;
88 const size_t span = _total_allocated - _priority_queue->total();
89 ObjectSample* sample;
90 if ((size_t)_priority_queue->count() == _size) {
91 assert(_list->count() == _size, "invariant");
92 const ObjectSample* peek = _priority_queue->peek();
93 if (peek->span() > span) {
94 // quick reject, will not fit
95 return;
96 }
97 sample = _list->reuse(_priority_queue->pop());
98 } else {
99 sample = _list->get();
100 }
101
102 assert(sample != NULL, "invariant");
103 assert(thread_id != 0, "invariant");
104 sample->set_thread_id(thread_id);
105 sample->set_thread_checkpoint(thread->jfr_thread_local()->thread_checkpoint());
106
107 if (stack_trace_id != 0) {
108 sample->set_stack_trace_id(stack_trace_id);
109 sample->set_stack_trace_hash(stack_trace_hash);
110 }
111
112 sample->set_span(allocated);
113 sample->set_object((oop)obj);
114 sample->set_allocated(allocated);
115 sample->set_allocation_time(JfrTicks::now());
116 sample->set_heap_used_at_last_gc(Universe::get_heap_used_at_last_gc());
117 _priority_queue->push(sample);
118 }
119
120 const ObjectSample* ObjectSampler::last() const {
121 return _list->last();
122 }
123
124 const ObjectSample* ObjectSampler::first() const {
125 return _list->first();
126 }
127
128 const ObjectSample* ObjectSampler::last_resolved() const {
129 return _list->last_resolved();
130 }
131
132 void ObjectSampler::set_last_resolved(const ObjectSample* sample) {
133 _list->set_last_resolved(sample);
134 }
135
136 void ObjectSampler::oops_do(BoolObjectClosure* is_alive, OopClosure* f) {
137 ObjectSample* current = _list->last();
138 while (current != NULL) {
139 ObjectSample* next = current->next();
140 if (!current->is_dead()) {
141 if (is_alive->do_object_b(current->object())) {
142 // The weakly referenced object is alive, update pointer
143 f->do_oop(const_cast<oop*>(current->object_addr()));
144 } else {
145 current->set_dead();
146 _dead_samples = true;
147 }
148 }
149 current = next;
150 }
151 _last_sweep = JfrTicks::now();
152 }
153
154 void ObjectSampler::remove_dead(ObjectSample* sample) {
155 assert(sample != NULL, "invariant");
156 assert(sample->is_dead(), "invariant");
157 ObjectSample* const previous = sample->prev();
158 // push span on to previous
159 if (previous != NULL) {
160 _priority_queue->remove(previous);
161 previous->add_span(sample->span());
162 _priority_queue->push(previous);
163 }
164 _priority_queue->remove(sample);
165 _list->release(sample);
166 }
167
168 void ObjectSampler::scavenge() {
169 ObjectSample* current = _list->last();
170 while (current != NULL) {
171 ObjectSample* next = current->next();
172 if (current->is_dead()) {
173 remove_dead(current);
174 }
175 current = next;
176 }
177 _dead_samples = false;
178 }
179
180 int ObjectSampler::item_count() const {
181 return _priority_queue->count();
182 }
183
184 const ObjectSample* ObjectSampler::item_at(int index) const {
185 return _priority_queue->item_at(index);
186 }
187
188 ObjectSample* ObjectSampler::item_at(int index) {
189 return const_cast<ObjectSample*>(
190 const_cast<const ObjectSampler*>(this)->item_at(index)
191 );
192 }
193
194 const JfrTicks& ObjectSampler::last_sweep() const {
195 return _last_sweep;
196 }