1 /* 2 * Copyright (c) 2001, 2018, 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_G1CONCURRENTMARKTHREAD_HPP 26 #define SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_HPP 27 28 #include "gc/shared/concurrentGCPhaseManager.hpp" 29 #include "gc/shared/concurrentGCThread.hpp" 30 31 class G1ConcurrentMark; 32 class G1Policy; 33 34 // The concurrent mark thread triggers the various steps of the concurrent marking 35 // cycle, including various marking cleanup. 36 class G1ConcurrentMarkThread: public ConcurrentGCThread { 37 friend class VMStructs; 38 39 double _vtime_start; // Initial virtual time. 40 double _vtime_accum; // Accumulated virtual time. 41 double _vtime_mark_accum; 42 43 G1ConcurrentMark* _cm; 44 45 enum State { 46 Idle, 47 Started, 48 InProgress 49 }; 50 51 volatile State _state; 52 53 // WhiteBox testing support. 54 ConcurrentGCPhaseManager::Stack _phase_manager_stack; 55 56 void sleep_before_next_cycle(); 57 // Delay marking to meet MMU. 58 void delay_to_keep_mmu(G1Policy* g1_policy, bool remark); 59 double mmu_sleep_time(G1Policy* g1_policy, bool remark); 60 61 void run_service(); 62 void stop_service(); 63 64 public: 65 // Constructor 66 G1ConcurrentMarkThread(G1ConcurrentMark* cm); 67 68 // Total virtual time so far for this thread and concurrent marking tasks. 69 double vtime_accum(); 70 // Marking virtual time so far this thread and concurrent marking tasks. 71 double vtime_mark_accum(); 72 cm()73 G1ConcurrentMark* cm() { return _cm; } 74 set_idle()75 void set_idle() { assert(_state != Started, "must not be starting a new cycle"); _state = Idle; } idle()76 bool idle() { return _state == Idle; } set_started()77 void set_started() { assert(_state == Idle, "cycle in progress"); _state = Started; } started()78 bool started() { return _state == Started; } set_in_progress()79 void set_in_progress() { assert(_state == Started, "must be starting a cycle"); _state = InProgress; } in_progress()80 bool in_progress() { return _state == InProgress; } 81 82 // Returns true from the moment a marking cycle is 83 // initiated (during the initial-mark pause when started() is set) 84 // to the moment when the cycle completes (just after the next 85 // marking bitmap has been cleared and in_progress() is 86 // cleared). While during_cycle() is true we will not start another cycle 87 // so that cycles do not overlap. We cannot use just in_progress() 88 // as the CM thread might take some time to wake up before noticing 89 // that started() is set and set in_progress(). during_cycle()90 bool during_cycle() { return !idle(); } 91 92 // WhiteBox testing support. 93 const char* const* concurrent_phases() const; 94 bool request_concurrent_phase(const char* phase); 95 phase_manager_stack()96 ConcurrentGCPhaseManager::Stack* phase_manager_stack() { 97 return &_phase_manager_stack; 98 } 99 }; 100 101 #endif // SHARE_VM_GC_G1_G1CONCURRENTMARKTHREAD_HPP 102