1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/shared/suspendibleThreadSet.hpp Fri Apr 11 12:29:24 2014 +0200
1.3 @@ -0,0 +1,84 @@
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 +#ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_SUSPENDIBLETHREADSET_HPP
1.29 +#define SHARE_VM_GC_IMPLEMENTATION_SHARED_SUSPENDIBLETHREADSET_HPP
1.30 +
1.31 +#include "memory/allocation.hpp"
1.32 +
1.33 +// A SuspendibleThreadSet is a set of threads that can be suspended.
1.34 +// A thread can join and later leave the set, and periodically yield.
1.35 +// If some thread (not in the set) requests, via synchronize(), that
1.36 +// the threads be suspended, then the requesting thread is blocked
1.37 +// until all the threads in the set have yielded or left the set. Threads
1.38 +// may not enter the set when an attempted suspension is in progress. The
1.39 +// suspending thread later calls desynchronize(), allowing the suspended
1.40 +// threads to continue.
1.41 +class SuspendibleThreadSet : public AllStatic {
1.42 +private:
1.43 + static uint _nthreads;
1.44 + static uint _nthreads_stopped;
1.45 + static bool _suspend_all;
1.46 + static double _suspend_all_start;
1.47 +
1.48 +public:
1.49 + // Add the current thread to the set. May block if a suspension is in progress.
1.50 + static void join();
1.51 +
1.52 + // Removes the current thread from the set.
1.53 + static void leave();
1.54 +
1.55 + // Returns true if an suspension is in progress.
1.56 + static bool should_yield() { return _suspend_all; }
1.57 +
1.58 + // Suspends the current thread if a suspension is in progress.
1.59 + static void yield();
1.60 +
1.61 + // Returns when all threads in the set are suspended.
1.62 + static void synchronize();
1.63 +
1.64 + // Resumes all suspended threads in the set.
1.65 + static void desynchronize();
1.66 +};
1.67 +
1.68 +class SuspendibleThreadSetJoiner : public StackObj {
1.69 +public:
1.70 + SuspendibleThreadSetJoiner() {
1.71 + SuspendibleThreadSet::join();
1.72 + }
1.73 +
1.74 + ~SuspendibleThreadSetJoiner() {
1.75 + SuspendibleThreadSet::leave();
1.76 + }
1.77 +
1.78 + bool should_yield() {
1.79 + return SuspendibleThreadSet::should_yield();
1.80 + }
1.81 +
1.82 + void yield() {
1.83 + SuspendibleThreadSet::yield();
1.84 + }
1.85 +};
1.86 +
1.87 +#endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_SUSPENDIBLETHREADSET_HPP
