1 /* 2 * Copyright (c) 2001, 2015, 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 #ifndef SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP 26 #define SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP 27 28 #include "gc/shared/concurrentGCThread.hpp" 29 30 // The Concurrent Mark GC Thread (could be several in the future). 31 // This is copied from the Concurrent Mark Sweep GC Thread 32 // Still under construction. 33 34 class ConcurrentMark; 35 36 class ConcurrentMarkThread: public ConcurrentGCThread { 37 friend class VMStructs; 38 39 double _vtime_start; // Initial virtual time. 40 double _vtime_accum; // Accumulated virtual time. 41 42 double _vtime_mark_accum; 43 44 public: 45 virtual void run(); 46 47 private: 48 ConcurrentMark* _cm; 49 volatile bool _started; 50 volatile bool _in_progress; 51 52 void sleepBeforeNextCycle(); 53 54 static SurrogateLockerThread* _slt; 55 56 public: 57 // Constructor 58 ConcurrentMarkThread(ConcurrentMark* cm); 59 60 static void makeSurrogateLockerThread(TRAPS); 61 static SurrogateLockerThread* slt() { return _slt; } 62 63 // Total virtual time so far. 64 double vtime_accum(); 65 // Marking virtual time so far 66 double vtime_mark_accum(); 67 68 ConcurrentMark* cm() { return _cm; } 69 70 void set_started() { assert(!_in_progress, "cycle in progress"); _started = true; } 71 void clear_started() { assert(_in_progress, "must be starting a cycle"); _started = false; } 72 bool started() { return _started; } 73 74 void set_in_progress() { assert(_started, "must be starting a cycle"); _in_progress = true; } 75 void clear_in_progress() { assert(!_started, "must not be starting a new cycle"); _in_progress = false; } 76 bool in_progress() { return _in_progress; } 77 78 // This flag returns true from the moment a marking cycle is 79 // initiated (during the initial-mark pause when started() is set) 80 // to the moment when the cycle completes (just after the next 81 // marking bitmap has been cleared and in_progress() is 82 // cleared). While this flag is true we will not start another cycle 83 // so that cycles do not overlap. We cannot use just in_progress() 84 // as the CM thread might take some time to wake up before noticing 85 // that started() is set and set in_progress(). 86 bool during_cycle() { return started() || in_progress(); } 87 88 // shutdown 89 void stop(); 90 }; 91 92 #endif // SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP