1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/shared/suspendibleThreadSet.cpp Fri Apr 11 12:29:24 2014 +0200
1.3 @@ -0,0 +1,93 @@
1.4 +/*
1.5 + * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "gc_implementation/shared/suspendibleThreadSet.hpp"
1.30 +#include "runtime/mutexLocker.hpp"
1.31 +#include "runtime/thread.inline.hpp"
1.32 +
1.33 +uint SuspendibleThreadSet::_nthreads = 0;
1.34 +uint SuspendibleThreadSet::_nthreads_stopped = 0;
1.35 +bool SuspendibleThreadSet::_suspend_all = false;
1.36 +double SuspendibleThreadSet::_suspend_all_start = 0.0;
1.37 +
1.38 +void SuspendibleThreadSet::join() {
1.39 + MonitorLockerEx ml(STS_lock, Mutex::_no_safepoint_check_flag);
1.40 + while (_suspend_all) {
1.41 + ml.wait(Mutex::_no_safepoint_check_flag);
1.42 + }
1.43 + _nthreads++;
1.44 +}
1.45 +
1.46 +void SuspendibleThreadSet::leave() {
1.47 + MonitorLockerEx ml(STS_lock, Mutex::_no_safepoint_check_flag);
1.48 + assert(_nthreads > 0, "Invalid");
1.49 + _nthreads--;
1.50 + if (_suspend_all) {
1.51 + ml.notify_all();
1.52 + }
1.53 +}
1.54 +
1.55 +void SuspendibleThreadSet::yield() {
1.56 + if (_suspend_all) {
1.57 + MonitorLockerEx ml(STS_lock, Mutex::_no_safepoint_check_flag);
1.58 + if (_suspend_all) {
1.59 + _nthreads_stopped++;
1.60 + if (_nthreads_stopped == _nthreads) {
1.61 + if (ConcGCYieldTimeout > 0) {
1.62 + double now = os::elapsedTime();
1.63 + guarantee((now - _suspend_all_start) * 1000.0 < (double)ConcGCYieldTimeout, "Long delay");
1.64 + }
1.65 + }
1.66 + ml.notify_all();
1.67 + while (_suspend_all) {
1.68 + ml.wait(Mutex::_no_safepoint_check_flag);
1.69 + }
1.70 + assert(_nthreads_stopped > 0, "Invalid");
1.71 + _nthreads_stopped--;
1.72 + ml.notify_all();
1.73 + }
1.74 + }
1.75 +}
1.76 +
1.77 +void SuspendibleThreadSet::synchronize() {
1.78 + assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1.79 + if (ConcGCYieldTimeout > 0) {
1.80 + _suspend_all_start = os::elapsedTime();
1.81 + }
1.82 + MonitorLockerEx ml(STS_lock, Mutex::_no_safepoint_check_flag);
1.83 + assert(!_suspend_all, "Only one at a time");
1.84 + _suspend_all = true;
1.85 + while (_nthreads_stopped < _nthreads) {
1.86 + ml.wait(Mutex::_no_safepoint_check_flag);
1.87 + }
1.88 +}
1.89 +
1.90 +void SuspendibleThreadSet::desynchronize() {
1.91 + assert(Thread::current()->is_VM_thread(), "Must be the VM thread");
1.92 + MonitorLockerEx ml(STS_lock, Mutex::_no_safepoint_check_flag);
1.93 + assert(_nthreads_stopped == _nthreads, "Invalid");
1.94 + _suspend_all = false;
1.95 + ml.notify_all();
1.96 +}
