concurrentMarkThread.hpp revision 9727:f944761a3ce3 
1/*
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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 CMConcurrentMarkingTasks
31// as well as handling various marking cleanup.
32
33class ConcurrentMark;
34class G1CollectorPolicy;
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
42  double _vtime_mark_accum;
43
44 public:
45  virtual void run();
46
47 private:
48  ConcurrentMark*                  _cm;
49
50  enum State {
51    Idle,
52    Started,
53    InProgress
54  };
55
56  volatile State _state;
57
58  void sleepBeforeNextCycle();
59  void delay_to_keep_mmu(G1CollectorPolicy* g1_policy, bool remark);
60
61  void run_service();
62  void stop_service();
63
64  static SurrogateLockerThread*         _slt;
65
66 public:
67  // Constructor
68  ConcurrentMarkThread(ConcurrentMark* cm);
69
70  static void makeSurrogateLockerThread(TRAPS);
71  static SurrogateLockerThread* slt() { return _slt; }
72
73  // Total virtual time so far for this thread and concurrent marking tasks.
74  double vtime_accum();
75  // Marking virtual time so far this thread and concurrent marking tasks.
76  double vtime_mark_accum();
77
78  ConcurrentMark* cm()     { return _cm; }
79
80  void set_idle()          { assert(_state != Started, "must not be starting a new cycle"); _state = Idle; }
81  bool idle()              { return _state == Idle; }
82  void set_started()       { assert(_state == Idle, "cycle in progress"); _state = Started; }
83  bool started()           { return _state == Started; }
84  void set_in_progress()   { assert(_state == Started, "must be starting a cycle"); _state = InProgress; }
85  bool in_progress()       { return _state == InProgress; }
86
87  // Returns true from the moment a marking cycle is
88  // initiated (during the initial-mark pause when started() is set)
89  // to the moment when the cycle completes (just after the next
90  // marking bitmap has been cleared and in_progress() is
91  // cleared). While during_cycle() is true we will not start another cycle
92  // so that cycles do not overlap. We cannot use just in_progress()
93  // as the CM thread might take some time to wake up before noticing
94  // that started() is set and set in_progress().
95  bool during_cycle()      { return !idle(); }
96
97  // shutdown
98  void stop();
99};
100
101#endif // SHARE_VM_GC_G1_CONCURRENTMARKTHREAD_HPP
102