1 /*
2 * Copyright (c) 2012, 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
25 #include "precompiled.hpp"
26 #include "runtime/threadCritical.hpp"
27 #include "services/memTracker.hpp"
28 #include "services/memTrackWorker.hpp"
29 #include "utilities/decoder.hpp"
30 #include "utilities/vmError.hpp"
31
32 MemTrackWorker::MemTrackWorker() {
33 // create thread uses cgc thread type for now. We should revisit
34 // the option, or create new thread type.
35 _has_error = !os::create_thread(this, os::cgc_thread);
36 set_name("MemTrackWorker", 0);
37
38 // initial generation circuit buffer
39 if (!has_error()) {
40 _head = _tail = 0;
41 for(int index = 0; index < MAX_GENERATIONS; index ++) {
42 _gen[index] = NULL;
43 }
44 }
45 NOT_PRODUCT(_sync_point_count = 0;)
46 NOT_PRODUCT(_merge_count = 0;)
47 NOT_PRODUCT(_last_gen_in_use = 0;)
48 }
49
50 MemTrackWorker::~MemTrackWorker() {
51 for (int index = 0; index < MAX_GENERATIONS; index ++) {
52 MemRecorder* rc = _gen[index];
53 if (rc != NULL) {
54 delete rc;
55 }
56 }
57 }
58
59 void* MemTrackWorker::operator new(size_t size) {
60 assert(false, "use nothrow version");
61 return NULL;
62 }
63
64 void* MemTrackWorker::operator new(size_t size, const std::nothrow_t& nothrow_constant) {
65 return allocate(size, false, mtNMT);
66 }
67
68 void MemTrackWorker::start() {
69 os::start_thread(this);
70 }
71
72 /*
73 * Native memory tracking worker thread loop:
74 * 1. merge one generation of memory recorders to staging area
75 * 2. promote staging data to memory snapshot
76 *
77 * This thread can run through safepoint.
78 */
79
80 void MemTrackWorker::run() {
81 assert(MemTracker::is_on(), "native memory tracking is off");
82 this->initialize_thread_local_storage();
83 this->record_stack_base_and_size();
84 MemSnapshot* snapshot = MemTracker::get_snapshot();
85 assert(snapshot != NULL, "Worker should not be started");
86 MemRecorder* rec;
87 unsigned long processing_generation = 0;
88 bool worker_idle = false;
89
90 while (!MemTracker::shutdown_in_progress()) {
91 NOT_PRODUCT(_last_gen_in_use = generations_in_use();)
92 {
93 // take a recorder from earliest generation in buffer
94 ThreadCritical tc;
95 rec = _gen[_head];
96 if (rec != NULL) {
97 _gen[_head] = rec->next();
98 }
99 assert(count_recorder(_gen[_head]) <= MemRecorder::_instance_count,
100 "infinite loop after dequeue");
101 }
102 if (rec != NULL) {
103 if (rec->get_generation() != processing_generation || worker_idle) {
104 processing_generation = rec->get_generation();
105 worker_idle = false;
106 MemTracker::set_current_processing_generation(processing_generation);
107 }
108
109 // merge the recorder into staging area
110 if (!snapshot->merge(rec)) {
111 MemTracker::shutdown(MemTracker::NMT_out_of_memory);
112 } else {
113 NOT_PRODUCT(_merge_count ++;)
114 }
115 MemTracker::release_thread_recorder(rec);
116 } else {
117 // no more recorder to merge, promote staging area
118 // to snapshot
119 if (_head != _tail) {
120 {
121 ThreadCritical tc;
122 if (_gen[_head] != NULL || _head == _tail) {
123 continue;
124 }
125 // done with this generation, increment _head pointer
126 _head = (_head + 1) % MAX_GENERATIONS;
127 }
128 // promote this generation data to snapshot
129 if (!snapshot->promote()) {
130 // failed to promote, means out of memory
131 MemTracker::shutdown(MemTracker::NMT_out_of_memory);
132 }
133 } else {
134 // worker thread is idle
135 worker_idle = true;
136 MemTracker::report_worker_idle();
137 snapshot->wait(1000);
138 ThreadCritical tc;
139 // check if more data arrived
140 if (_gen[_head] == NULL) {
141 _gen[_head] = MemTracker::get_pending_recorders();
142 }
143 }
144 }
145 }
146 assert(MemTracker::shutdown_in_progress(), "just check");
147
148 // transits to final shutdown
149 MemTracker::final_shutdown();
150 }
151
152 // at synchronization point, where 'safepoint visible' Java threads are blocked
153 // at a safepoint, and the rest of threads are blocked on ThreadCritical lock.
154 // The caller MemTracker::sync() already takes ThreadCritical before calling this
155 // method.
156 //
157 // Following tasks are performed:
158 // 1. add all recorders in pending queue to current generation
159 // 2. increase generation
160
161 void MemTrackWorker::at_sync_point(MemRecorder* rec) {
162 NOT_PRODUCT(_sync_point_count ++;)
163 assert(count_recorder(rec) <= MemRecorder::_instance_count,
164 "pending queue has infinite loop");
165
166 bool out_of_generation_buffer = false;
167 // check shutdown state inside ThreadCritical
168 if (MemTracker::shutdown_in_progress()) return;
169 // append the recorders to the end of the generation
170 if( rec != NULL) {
171 MemRecorder* cur_head = _gen[_tail];
172 if (cur_head == NULL) {
173 _gen[_tail] = rec;
174 } else {
175 while (cur_head->next() != NULL) {
176 cur_head = cur_head->next();
177 }
178 cur_head->set_next(rec);
179 }
180 }
181 assert(count_recorder(rec) <= MemRecorder::_instance_count,
182 "after add to current generation has infinite loop");
183 // we have collected all recorders for this generation. If there is data,
184 // we need to increment _tail to start a new generation.
185 if (_gen[_tail] != NULL || _head == _tail) {
186 _tail = (_tail + 1) % MAX_GENERATIONS;
187 out_of_generation_buffer = (_tail == _head);
188 }
189
190 if (out_of_generation_buffer) {
191 MemTracker::shutdown(MemTracker::NMT_out_of_generation);
192 }
193 }
194
195 #ifndef PRODUCT
196 int MemTrackWorker::count_recorder(const MemRecorder* head) {
197 int count = 0;
198 while(head != NULL) {
199 count ++;
200 head = head->next();
201 }
202 return count;
203 }
204
205 int MemTrackWorker::count_pending_recorders() const {
206 int count = 0;
207 for (int index = 0; index < MAX_GENERATIONS; index ++) {
208 MemRecorder* head = _gen[index];
209 if (head != NULL) {
210 count += count_recorder(head);
211 }
212 }
213 return count;
214 }
215 #endif