1
2 /*
3 * Copyright (c) 2002, 2015, Oracle and/or its affiliates. All rights reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "gc_implementation/parallelScavenge/gcTaskManager.hpp"
28 #include "gc_implementation/parallelScavenge/gcTaskThread.hpp"
29 #include "memory/allocation.hpp"
30 #include "memory/allocation.inline.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "runtime/handles.hpp"
33 #include "runtime/handles.inline.hpp"
34 #include "runtime/os.hpp"
35 #include "runtime/thread.hpp"
36
37 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
38
39 GCTaskThread::GCTaskThread(GCTaskManager* manager,
40 uint which,
41 uint processor_id) :
42 _manager(manager),
43 _processor_id(processor_id),
44 _time_stamps(NULL),
45 _time_stamp_index(0)
46 {
47 if (!os::create_thread(this, os::pgc_thread))
48 vm_exit_out_of_memory(0, OOM_MALLOC_ERROR, "Cannot create GC thread. Out of system resources.");
49
50 if (PrintGCTaskTimeStamps) {
51 _time_stamps = NEW_C_HEAP_ARRAY(GCTaskTimeStamp, GCTaskTimeStampEntries, mtGC);
52
53 guarantee(_time_stamps != NULL, "Sanity");
54 }
55 set_id(which);
56 set_name("GC task thread#%d (ParallelGC)", which);
57 }
58
59 GCTaskThread::~GCTaskThread() {
60 if (_time_stamps != NULL) {
61 FREE_C_HEAP_ARRAY(GCTaskTimeStamp, _time_stamps);
62 }
63 }
64
65 void GCTaskThread::start() {
66 os::start_thread(this);
67 }
68
69 GCTaskTimeStamp* GCTaskThread::time_stamp_at(uint index) {
70 guarantee(index < GCTaskTimeStampEntries, "increase GCTaskTimeStampEntries");
71
72 return &(_time_stamps[index]);
73 }
74
75 void GCTaskThread::print_task_time_stamps() {
76 assert(PrintGCTaskTimeStamps, "Sanity");
77 assert(_time_stamps != NULL, "Sanity (Probably set PrintGCTaskTimeStamps late)");
78
79 tty->print_cr("GC-Thread %u entries: %d", id(), _time_stamp_index);
80 for(uint i=0; i<_time_stamp_index; i++) {
81 GCTaskTimeStamp* time_stamp = time_stamp_at(i);
82 tty->print_cr("\t[ %s " INT64_FORMAT " " INT64_FORMAT " ]",
83 time_stamp->name(),
84 time_stamp->entry_time(),
85 time_stamp->exit_time());
86 }
87
88 // Reset after dumping the data
89 _time_stamp_index = 0;
90 }
91
92 // GC workers get tasks from the GCTaskManager and execute
93 // them in this method. If there are no tasks to execute,
94 // the GC workers wait in the GCTaskManager's get_task()
95 // for tasks to be enqueued for execution.
96
97 void GCTaskThread::run() {
98 // Set up the thread for stack overflow support
99 this->record_stack_base_and_size();
100 this->initialize_thread_local_storage();
101 this->initialize_named_thread();
102 // Bind yourself to your processor.
103 if (processor_id() != GCTaskManager::sentinel_worker()) {
104 if (TraceGCTaskThread) {
105 tty->print_cr("GCTaskThread::run: "
106 " binding to processor %u", processor_id());
107 }
108 if (!os::bind_to_processor(processor_id())) {
109 DEBUG_ONLY(
110 warning("Couldn't bind GCTaskThread %u to processor %u",
111 which(), processor_id());
112 )
113 }
114 }
115 // Part of thread setup.
116 // ??? Are these set up once here to make subsequent ones fast?
117 HandleMark hm_outer;
118 ResourceMark rm_outer;
119
120 TimeStamp timer;
121
122 for (;/* ever */;) {
123 // These are so we can flush the resources allocated in the inner loop.
124 HandleMark hm_inner;
125 ResourceMark rm_inner;
126 for (; /* break */; ) {
127 // This will block until there is a task to be gotten.
128 GCTask* task = manager()->get_task(which());
129 // Record if this is an idle task for later use.
130 bool is_idle_task = task->is_idle_task();
131 // In case the update is costly
132 if (PrintGCTaskTimeStamps) {
133 timer.update();
134 }
135
136 jlong entry_time = timer.ticks();
137 char* name = task->name();
138
139 // If this is the barrier task, it can be destroyed
140 // by the GC task manager once the do_it() executes.
141 task->do_it(manager(), which());
142
143 // Use the saved value of is_idle_task because references
144 // using "task" are not reliable for the barrier task.
145 if (!is_idle_task) {
146 manager()->note_completion(which());
147
148 if (PrintGCTaskTimeStamps) {
149 assert(_time_stamps != NULL,
150 "Sanity (PrintGCTaskTimeStamps set late?)");
151
152 timer.update();
153
154 GCTaskTimeStamp* time_stamp = time_stamp_at(_time_stamp_index++);
155
156 time_stamp->set_name(name);
157 time_stamp->set_entry_time(entry_time);
158 time_stamp->set_exit_time(timer.ticks());
159 }
160 } else {
161 // idle tasks complete outside the normal accounting
162 // so that a task can complete without waiting for idle tasks.
163 // They have to be terminated separately.
164 IdleGCTask::destroy((IdleGCTask*)task);
165 set_is_working(true);
166 }
167
168 // Check if we should release our inner resources.
169 if (manager()->should_release_resources(which())) {
170 manager()->note_release(which());
171 break;
172 }
173 }
174 }
175 }