1 /*
2 * Copyright (c) 2001, 2016, 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 "classfile/systemDictionary.hpp"
27 #include "gc/shared/concurrentGCThread.hpp"
28 #include "oops/instanceRefKlass.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "runtime/init.hpp"
31 #include "runtime/java.hpp"
32 #include "runtime/javaCalls.hpp"
33 #include "runtime/os.hpp"
34
35 ConcurrentGCThread::ConcurrentGCThread() :
36 _should_terminate(false), _has_terminated(false) {
37 };
38
39 void ConcurrentGCThread::create_and_start(ThreadPriority prio) {
40 if (os::create_thread(this, os::cgc_thread)) {
41 // XXX: need to set this to low priority
42 // unless "aggressive mode" set; priority
43 // should be just less than that of VMThread.
44 os::set_priority(this, prio);
45 if (!_should_terminate) {
46 os::start_thread(this);
47 }
48 }
49 }
50
51 void ConcurrentGCThread::initialize_in_thread() {
52 this->record_stack_base_and_size();
53 this->initialize_named_thread();
54 this->set_active_handles(JNIHandleBlock::allocate_block());
55 // From this time Thread::current() should be working.
56 assert(this == Thread::current(), "just checking");
57 }
58
59 void ConcurrentGCThread::wait_for_universe_init() {
60 MutexLockerEx x(CGC_lock, Mutex::_no_safepoint_check_flag);
61 while (!is_init_completed() && !_should_terminate) {
62 CGC_lock->wait(Mutex::_no_safepoint_check_flag, 1);
63 }
64 }
65
66 void ConcurrentGCThread::terminate() {
67 assert(_should_terminate, "Should only be called on terminate request.");
68 // Signal that it is terminated
69 {
70 MutexLocker mu(Terminator_lock);
71 _has_terminated = true;
72 Terminator_lock->notify();
73 }
74 }
75
76 void ConcurrentGCThread::run() {
77 initialize_in_thread();
78 wait_for_universe_init();
79
80 run_service();
81
82 terminate();
83 }
84
85 void ConcurrentGCThread::stop() {
86 // it is ok to take late safepoints here, if needed
87 {
88 MutexLockerEx mu(Terminator_lock);
89 assert(!_has_terminated, "stop should only be called once");
90 assert(!_should_terminate, "stop should only be called once");
91 _should_terminate = true;
92 }
93
94 stop_service();
95
96 {
97 MutexLockerEx mu(Terminator_lock);
98 while (!_has_terminated) {
99 Terminator_lock->wait();
100 }
101 }
102 }
--- EOF ---