1/*
2 * Copyright (c) 2001, 2019, 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 "gc/shared/concurrentGCThread.hpp"
27#include "runtime/init.hpp"
28#include "runtime/mutexLocker.hpp"
29#include "runtime/orderAccess.hpp"
30#include "runtime/os.hpp"
31
32ConcurrentGCThread::ConcurrentGCThread() :
33 _should_terminate(false),
34 _has_terminated(false) {}
35
36void ConcurrentGCThread::create_and_start(ThreadPriority prio) {
37 if (os::create_thread(this, os::cgc_thread)) {
38 os::set_priority(this, prio);
39 os::start_thread(this);
40 }
41}
42
43void ConcurrentGCThread::run() {
44 // Setup handle area
45 set_active_handles(JNIHandleBlock::allocate_block());
46
47 // Wait for initialization to complete
48 wait_init_completed();
49
50 run_service();
51
52 // Signal thread has terminated
53 MonitorLocker ml(Terminator_lock);
54 OrderAccess::release_store(&_has_terminated, true);
55 ml.notify_all();
56}
57
58void ConcurrentGCThread::stop() {
59 assert(!should_terminate(), "Invalid state");
60 assert(!has_terminated(), "Invalid state");
61
62 // Signal thread to terminate
63 OrderAccess::release_store_fence(&_should_terminate, true);
64
65 stop_service();
66
67 // Wait for thread to terminate
68 MonitorLocker ml(Terminator_lock);
69 while (!_has_terminated) {
70 ml.wait();
71 }
72}
73
74bool ConcurrentGCThread::should_terminate() const {
75 return OrderAccess::load_acquire(&_should_terminate);
76}
77
78bool ConcurrentGCThread::has_terminated() const {
79 return OrderAccess::load_acquire(&_has_terminated);
80}
81