1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/shared/concurrentGCThread.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,175 @@
1.4 +/*
1.5 + * Copyright (c) 2001, 2013, 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_CONCURRENTGCTHREAD_HPP
1.29 +#define SHARE_VM_GC_IMPLEMENTATION_SHARED_CONCURRENTGCTHREAD_HPP
1.30 +
1.31 +#include "utilities/macros.hpp"
1.32 +#if INCLUDE_ALL_GCS
1.33 +#include "runtime/thread.hpp"
1.34 +#endif // INCLUDE_ALL_GCS
1.35 +
1.36 +class VoidClosure;
1.37 +
1.38 +// A SuspendibleThreadSet is (obviously) a set of threads that can be
1.39 +// suspended. A thread can join and later leave the set, and periodically
1.40 +// yield. If some thread (not in the set) requests, via suspend_all, that
1.41 +// the threads be suspended, then the requesting thread is blocked until
1.42 +// all the threads in the set have yielded or left the set. (Threads may
1.43 +// not enter the set when an attempted suspension is in progress.) The
1.44 +// suspending thread later calls resume_all, allowing the suspended threads
1.45 +// to continue.
1.46 +
1.47 +class SuspendibleThreadSet {
1.48 + Monitor* _m;
1.49 + int _async;
1.50 + bool _async_stop;
1.51 + int _async_stopped;
1.52 + bool _initialized;
1.53 + double _suspend_all_start;
1.54 +
1.55 + void initialize_work();
1.56 +
1.57 + public:
1.58 + SuspendibleThreadSet() : _initialized(false) {}
1.59 +
1.60 + // Add the current thread to the set. May block if a suspension
1.61 + // is in progress.
1.62 + void join();
1.63 + // Removes the current thread from the set.
1.64 + void leave();
1.65 + // Returns "true" iff an suspension is in progress.
1.66 + bool should_yield() { return _async_stop; }
1.67 + // Suspends the current thread if a suspension is in progress (for
1.68 + // the duration of the suspension.)
1.69 + void yield(const char* id);
1.70 + // Return when all threads in the set are suspended.
1.71 + void suspend_all();
1.72 + // Allow suspended threads to resume.
1.73 + void resume_all();
1.74 + // Redundant initializations okay.
1.75 + void initialize() {
1.76 + // Double-check dirty read idiom.
1.77 + if (!_initialized) initialize_work();
1.78 + }
1.79 +};
1.80 +
1.81 +
1.82 +class ConcurrentGCThread: public NamedThread {
1.83 + friend class VMStructs;
1.84 +
1.85 +protected:
1.86 + bool _should_terminate;
1.87 + bool _has_terminated;
1.88 +
1.89 + enum CGC_flag_type {
1.90 + CGC_nil = 0x0,
1.91 + CGC_dont_suspend = 0x1,
1.92 + CGC_CGC_safepoint = 0x2,
1.93 + CGC_VM_safepoint = 0x4
1.94 + };
1.95 +
1.96 + static int _CGC_flag;
1.97 +
1.98 + static bool CGC_flag_is_set(int b) { return (_CGC_flag & b) != 0; }
1.99 + static int set_CGC_flag(int b) { return _CGC_flag |= b; }
1.100 + static int reset_CGC_flag(int b) { return _CGC_flag &= ~b; }
1.101 +
1.102 + // All instances share this one set.
1.103 + static SuspendibleThreadSet _sts;
1.104 +
1.105 + // Create and start the thread (setting it's priority high.)
1.106 + void create_and_start();
1.107 +
1.108 + // Do initialization steps in the thread: record stack base and size,
1.109 + // init thread local storage, set JNI handle block.
1.110 + void initialize_in_thread();
1.111 +
1.112 + // Wait until Universe::is_fully_initialized();
1.113 + void wait_for_universe_init();
1.114 +
1.115 + // Record that the current thread is terminating, and will do more
1.116 + // concurrent work.
1.117 + void terminate();
1.118 +
1.119 +public:
1.120 + // Constructor
1.121 +
1.122 + ConcurrentGCThread();
1.123 + ~ConcurrentGCThread() {} // Exists to call NamedThread destructor.
1.124 +
1.125 + // Tester
1.126 + bool is_ConcurrentGC_thread() const { return true; }
1.127 +
1.128 + static void safepoint_synchronize();
1.129 + static void safepoint_desynchronize();
1.130 +
1.131 + // All overridings should probably do _sts::yield, but we allow
1.132 + // overriding for distinguished debugging messages. Default is to do
1.133 + // nothing.
1.134 + virtual void yield() {}
1.135 +
1.136 + bool should_yield() { return _sts.should_yield(); }
1.137 +
1.138 + // they are prefixed by sts since there are already yield() and
1.139 + // should_yield() (non-static) methods in this class and it was an
1.140 + // easy way to differentiate them.
1.141 + static void stsYield(const char* id);
1.142 + static bool stsShouldYield();
1.143 + static void stsJoin();
1.144 + static void stsLeave();
1.145 +
1.146 +};
1.147 +
1.148 +// The SurrogateLockerThread is used by concurrent GC threads for
1.149 +// manipulating Java monitors, in particular, currently for
1.150 +// manipulating the pending_list_lock. XXX
1.151 +class SurrogateLockerThread: public JavaThread {
1.152 + friend class VMStructs;
1.153 + public:
1.154 + enum SLT_msg_type {
1.155 + empty = 0, // no message
1.156 + acquirePLL, // acquire pending list lock
1.157 + releaseAndNotifyPLL // notify and release pending list lock
1.158 + };
1.159 + private:
1.160 + // the following are shared with the CMSThread
1.161 + SLT_msg_type _buffer; // communication buffer
1.162 + Monitor _monitor; // monitor controlling buffer
1.163 + BasicLock _basicLock; // used for PLL locking
1.164 +
1.165 + public:
1.166 + static SurrogateLockerThread* make(TRAPS);
1.167 +
1.168 + SurrogateLockerThread();
1.169 +
1.170 + bool is_hidden_from_external_view() const { return true; }
1.171 +
1.172 + void loop(); // main method
1.173 +
1.174 + void manipulatePLL(SLT_msg_type msg);
1.175 +
1.176 +};
1.177 +
1.178 +#endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_CONCURRENTGCTHREAD_HPP
