Mercurial > hg > graal-jvmci-8
diff src/share/vm/gc_implementation/shared/suspendibleThreadSet.hpp @ 20192:581e70386ec9
8039147: Cleanup SuspendibleThreadSet
Reviewed-by: brutisso, tschatzl, mgerdin
author | pliden |
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date | Fri, 11 Apr 2014 12:29:24 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/shared/suspendibleThreadSet.hpp Fri Apr 11 12:29:24 2014 +0200 @@ -0,0 +1,84 @@ +/* + * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_SUSPENDIBLETHREADSET_HPP +#define SHARE_VM_GC_IMPLEMENTATION_SHARED_SUSPENDIBLETHREADSET_HPP + +#include "memory/allocation.hpp" + +// A SuspendibleThreadSet is a set of threads that can be suspended. +// A thread can join and later leave the set, and periodically yield. +// If some thread (not in the set) requests, via synchronize(), that +// the threads be suspended, then the requesting thread is blocked +// until all the threads in the set have yielded or left the set. Threads +// may not enter the set when an attempted suspension is in progress. The +// suspending thread later calls desynchronize(), allowing the suspended +// threads to continue. +class SuspendibleThreadSet : public AllStatic { +private: + static uint _nthreads; + static uint _nthreads_stopped; + static bool _suspend_all; + static double _suspend_all_start; + +public: + // Add the current thread to the set. May block if a suspension is in progress. + static void join(); + + // Removes the current thread from the set. + static void leave(); + + // Returns true if an suspension is in progress. + static bool should_yield() { return _suspend_all; } + + // Suspends the current thread if a suspension is in progress. + static void yield(); + + // Returns when all threads in the set are suspended. + static void synchronize(); + + // Resumes all suspended threads in the set. + static void desynchronize(); +}; + +class SuspendibleThreadSetJoiner : public StackObj { +public: + SuspendibleThreadSetJoiner() { + SuspendibleThreadSet::join(); + } + + ~SuspendibleThreadSetJoiner() { + SuspendibleThreadSet::leave(); + } + + bool should_yield() { + return SuspendibleThreadSet::should_yield(); + } + + void yield() { + SuspendibleThreadSet::yield(); + } +}; + +#endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_SUSPENDIBLETHREADSET_HPP