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24 
25 #ifndef SHARE_GC_G1_G1CONCURRENTMARKTHREAD_HPP
26 #define SHARE_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_delay_end(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   bool request_concurrent_phase(const char* phase);
94 
phase_manager_stack()95   ConcurrentGCPhaseManager::Stack* phase_manager_stack() {
96     return &_phase_manager_stack;
97   }
98 };
99 
100 #endif // SHARE_GC_G1_G1CONCURRENTMARKTHREAD_HPP
101