Mon, 02 Aug 2010 12:51:43 -0700
6814437: G1: remove the _new_refs array
Summary: The per-worker _new_refs array is used to hold references that point into the collection set. It is populated during RSet updating and subsequently processed. In the event of an evacuation failure it processed again to recreate the RSets of regions in the collection set. Remove the per-worker _new_refs array by processing the references directly. Use a DirtyCardQueue to hold the cards containing the references so that the RSets of regions in the collection set can be recreated when handling an evacuation failure.
Reviewed-by: iveresov, jmasa, tonyp
1 /*
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25 // The Concurrent Mark GC Thread (could be several in the future).
26 // This is copied from the Concurrent Mark Sweep GC Thread
27 // Still under construction.
29 class ConcurrentMark;
31 class ConcurrentMarkThread: public ConcurrentGCThread {
32 friend class VMStructs;
34 double _vtime_start; // Initial virtual time.
35 double _vtime_accum; // Accumulated virtual time.
37 double _vtime_mark_accum;
38 double _vtime_count_accum;
40 public:
41 virtual void run();
43 private:
44 ConcurrentMark* _cm;
45 volatile bool _started;
46 volatile bool _in_progress;
48 void sleepBeforeNextCycle();
50 static SurrogateLockerThread* _slt;
52 public:
53 // Constructor
54 ConcurrentMarkThread(ConcurrentMark* cm);
56 static void makeSurrogateLockerThread(TRAPS);
57 static SurrogateLockerThread* slt() { return _slt; }
59 // Printing
60 void print_on(outputStream* st) const;
61 void print() const;
63 // Total virtual time so far.
64 double vtime_accum();
65 // Marking virtual time so far
66 double vtime_mark_accum();
67 // Counting virtual time so far.
68 double vtime_count_accum() { return _vtime_count_accum; }
70 ConcurrentMark* cm() { return _cm; }
72 void set_started() { _started = true; }
73 void clear_started() { _started = false; }
74 bool started() { return _started; }
76 void set_in_progress() { _in_progress = true; }
77 void clear_in_progress() { _in_progress = false; }
78 bool in_progress() { return _in_progress; }
80 // This flag returns true from the moment a marking cycle is
81 // initiated (during the initial-mark pause when started() is set)
82 // to the moment when the cycle completes (just after the next
83 // marking bitmap has been cleared and in_progress() is
84 // cleared). While this flag is true we will not start another cycle
85 // so that cycles do not overlap. We cannot use just in_progress()
86 // as the CM thread might take some time to wake up before noticing
87 // that started() is set and set in_progress().
88 bool during_cycle() { return started() || in_progress(); }
90 // Yield for GC
91 void yield();
93 // shutdown
94 void stop();
95 };