Sun, 03 Feb 2013 22:28:08 +0400
8002048: Protocol to discovery of manageable Java processes on a network
Summary: Introduce a protocol to discover manageble Java instances across a network subnet, JDP
Reviewed-by: sla, dfuchs
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 */
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"
33 void GenerationData::reset() {
34 _number_of_classes = 0;
35 while (_recorder_list != NULL) {
36 MemRecorder* tmp = _recorder_list;
37 _recorder_list = _recorder_list->next();
38 MemTracker::release_thread_recorder(tmp);
39 }
40 }
42 MemTrackWorker::MemTrackWorker() {
43 // create thread uses cgc thread type for now. We should revisit
44 // the option, or create new thread type.
45 _has_error = !os::create_thread(this, os::cgc_thread);
46 set_name("MemTrackWorker", 0);
48 // initial generation circuit buffer
49 if (!has_error()) {
50 _head = _tail = 0;
51 for(int index = 0; index < MAX_GENERATIONS; index ++) {
52 ::new ((void*)&_gen[index]) GenerationData();
53 }
54 }
55 NOT_PRODUCT(_sync_point_count = 0;)
56 NOT_PRODUCT(_merge_count = 0;)
57 NOT_PRODUCT(_last_gen_in_use = 0;)
58 }
60 MemTrackWorker::~MemTrackWorker() {
61 for (int index = 0; index < MAX_GENERATIONS; index ++) {
62 _gen[index].reset();
63 }
64 }
66 void* MemTrackWorker::operator new(size_t size) {
67 assert(false, "use nothrow version");
68 return NULL;
69 }
71 void* MemTrackWorker::operator new(size_t size, const std::nothrow_t& nothrow_constant) {
72 return allocate(size, false, mtNMT);
73 }
75 void MemTrackWorker::start() {
76 os::start_thread(this);
77 }
79 /*
80 * Native memory tracking worker thread loop:
81 * 1. merge one generation of memory recorders to staging area
82 * 2. promote staging data to memory snapshot
83 *
84 * This thread can run through safepoint.
85 */
87 void MemTrackWorker::run() {
88 assert(MemTracker::is_on(), "native memory tracking is off");
89 this->initialize_thread_local_storage();
90 this->record_stack_base_and_size();
91 MemSnapshot* snapshot = MemTracker::get_snapshot();
92 assert(snapshot != NULL, "Worker should not be started");
93 MemRecorder* rec;
94 unsigned long processing_generation = 0;
95 bool worker_idle = false;
97 while (!MemTracker::shutdown_in_progress()) {
98 NOT_PRODUCT(_last_gen_in_use = generations_in_use();)
99 {
100 // take a recorder from earliest generation in buffer
101 ThreadCritical tc;
102 rec = _gen[_head].next_recorder();
103 }
104 if (rec != NULL) {
105 if (rec->get_generation() != processing_generation || worker_idle) {
106 processing_generation = rec->get_generation();
107 worker_idle = false;
108 MemTracker::set_current_processing_generation(processing_generation);
109 }
111 // merge the recorder into staging area
112 if (!snapshot->merge(rec)) {
113 MemTracker::shutdown(MemTracker::NMT_out_of_memory);
114 } else {
115 NOT_PRODUCT(_merge_count ++;)
116 }
117 MemTracker::release_thread_recorder(rec);
118 } else {
119 // no more recorder to merge, promote staging area
120 // to snapshot
121 if (_head != _tail) {
122 long number_of_classes;
123 {
124 ThreadCritical tc;
125 if (_gen[_head].has_more_recorder() || _head == _tail) {
126 continue;
127 }
128 number_of_classes = _gen[_head].number_of_classes();
129 _gen[_head].reset();
131 // done with this generation, increment _head pointer
132 _head = (_head + 1) % MAX_GENERATIONS;
133 }
134 // promote this generation data to snapshot
135 if (!snapshot->promote(number_of_classes)) {
136 // failed to promote, means out of memory
137 MemTracker::shutdown(MemTracker::NMT_out_of_memory);
138 }
139 } else {
140 // worker thread is idle
141 worker_idle = true;
142 MemTracker::report_worker_idle();
143 snapshot->wait(1000);
144 ThreadCritical tc;
145 // check if more data arrived
146 if (!_gen[_head].has_more_recorder()) {
147 _gen[_head].add_recorders(MemTracker::get_pending_recorders());
148 }
149 }
150 }
151 }
152 assert(MemTracker::shutdown_in_progress(), "just check");
154 // transits to final shutdown
155 MemTracker::final_shutdown();
156 }
158 // at synchronization point, where 'safepoint visible' Java threads are blocked
159 // at a safepoint, and the rest of threads are blocked on ThreadCritical lock.
160 // The caller MemTracker::sync() already takes ThreadCritical before calling this
161 // method.
162 //
163 // Following tasks are performed:
164 // 1. add all recorders in pending queue to current generation
165 // 2. increase generation
167 void MemTrackWorker::at_sync_point(MemRecorder* rec, int number_of_classes) {
168 NOT_PRODUCT(_sync_point_count ++;)
169 assert(count_recorder(rec) <= MemRecorder::_instance_count,
170 "pending queue has infinite loop");
172 bool out_of_generation_buffer = false;
173 // check shutdown state inside ThreadCritical
174 if (MemTracker::shutdown_in_progress()) return;
176 _gen[_tail].set_number_of_classes(number_of_classes);
177 // append the recorders to the end of the generation
178 _gen[_tail].add_recorders(rec);
179 assert(count_recorder(_gen[_tail].peek()) <= MemRecorder::_instance_count,
180 "after add to current generation has infinite loop");
181 // we have collected all recorders for this generation. If there is data,
182 // we need to increment _tail to start a new generation.
183 if (_gen[_tail].has_more_recorder() || _head == _tail) {
184 _tail = (_tail + 1) % MAX_GENERATIONS;
185 out_of_generation_buffer = (_tail == _head);
186 }
188 if (out_of_generation_buffer) {
189 MemTracker::shutdown(MemTracker::NMT_out_of_generation);
190 }
191 }
193 #ifndef PRODUCT
194 int MemTrackWorker::count_recorder(const MemRecorder* head) {
195 int count = 0;
196 while(head != NULL) {
197 count ++;
198 head = head->next();
199 }
200 return count;
201 }
203 int MemTrackWorker::count_pending_recorders() const {
204 int count = 0;
205 for (int index = 0; index < MAX_GENERATIONS; index ++) {
206 MemRecorder* head = _gen[index].peek();
207 if (head != NULL) {
208 count += count_recorder(head);
209 }
210 }
211 return count;
212 }
213 #endif