1 /* 2 * Copyright (c) 2001, 2017, 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/concurrentGCPhaseManager.hpp" 29 #include "gc/shared/concurrentGCThread.hpp" 30 31 // The Concurrent Mark GC Thread triggers the parallel G1CMConcurrentMarkingTasks 32 // as well as handling various marking cleanup. 33 34 class G1ConcurrentMark; 35 class G1Policy; 36 37 class ConcurrentMarkThread: public ConcurrentGCThread { 38 friend class VMStructs; 39 40 double _vtime_start; // Initial virtual time. 41 double _vtime_accum; // Accumulated virtual time. 42 double _vtime_mark_accum; 43 44 G1ConcurrentMark* _cm; 45 46 enum State { 47 Idle, 48 Started, 49 InProgress 50 }; 51 52 volatile State _state; 53 54 // WhiteBox testing support. 55 ConcurrentGCPhaseManager::Stack _phase_manager_stack; 56 57 void sleepBeforeNextCycle(); 58 void delay_to_keep_mmu(G1Policy* g1_policy, bool remark); 59 60 void run_service(); 61 void stop_service(); 62 63 public: 64 // Constructor 65 ConcurrentMarkThread(G1ConcurrentMark* cm); 66 67 // Total virtual time so far for this thread and concurrent marking tasks. 68 double vtime_accum(); 69 // Marking virtual time so far this thread and concurrent marking tasks. 70 double vtime_mark_accum(); 71 72 G1ConcurrentMark* cm() { return _cm; } 73 74 void set_idle() { assert(_state != Started, "must not be starting a new cycle"); _state = Idle; } 75 bool idle() { return _state == Idle; } 76 void set_started() { assert(_state == Idle, "cycle in progress"); _state = Started; } 77 bool started() { return _state == Started; } 78 void set_in_progress() { assert(_state == Started, "must be starting a cycle"); _state = InProgress; } 79 bool in_progress() { return _state == InProgress; } 80 81 // Returns true from the moment a marking cycle is 82 // initiated (during the initial-mark pause when started() is set) 83 // to the moment when the cycle completes (just after the next 84 // marking bitmap has been cleared and in_progress() is 85 // cleared). While during_cycle() is true we will not start another cycle 86 // so that cycles do not overlap. We cannot use just in_progress() 87 // as the CM thread might take some time to wake up before noticing 88 // that started() is set and set in_progress(). 89 bool during_cycle() { return !idle(); } 90 91 // WhiteBox testing support. 92 const char* const* concurrent_phases() const; 93 bool request_concurrent_phase(const char* phase); 94 95 ConcurrentGCPhaseManager::Stack* phase_manager_stack() { 96 return &_phase_manager_stack; 97 } 98 }; 99 100 #endif // SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP