1/*
2 * Copyright (c) 2001, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
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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
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14 *
15 * You should have received a copy of the GNU General Public License version
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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 triggers the parallel G1CMConcurrentMarkingTasks
31// as well as handling various marking cleanup.
32
33class G1ConcurrentMark;
34class G1Policy;
35
36class ConcurrentMarkThread: 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  void sleepBeforeNextCycle();
54  void delay_to_keep_mmu(G1Policy* g1_policy, bool remark);
55
56  void run_service();
57  void stop_service();
58
59 public:
60  // Constructor
61  ConcurrentMarkThread(G1ConcurrentMark* cm);
62
63  // Total virtual time so far for this thread and concurrent marking tasks.
64  double vtime_accum();
65  // Marking virtual time so far this thread and concurrent marking tasks.
66  double vtime_mark_accum();
67
68  G1ConcurrentMark* cm()   { return _cm; }
69
70  void set_idle()          { assert(_state != Started, "must not be starting a new cycle"); _state = Idle; }
71  bool idle()              { return _state == Idle; }
72  void set_started()       { assert(_state == Idle, "cycle in progress"); _state = Started; }
73  bool started()           { return _state == Started; }
74  void set_in_progress()   { assert(_state == Started, "must be starting a cycle"); _state = InProgress; }
75  bool in_progress()       { return _state == InProgress; }
76
77  // Returns true from the moment a marking cycle is
78  // initiated (during the initial-mark pause when started() is set)
79  // to the moment when the cycle completes (just after the next
80  // marking bitmap has been cleared and in_progress() is
81  // cleared). While during_cycle() is true we will not start another cycle
82  // so that cycles do not overlap. We cannot use just in_progress()
83  // as the CM thread might take some time to wake up before noticing
84  // that started() is set and set in_progress().
85  bool during_cycle()      { return !idle(); }
86};
87
88#endif // SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP
89