Thu, 21 Aug 2014 16:44:41 +0200
8055098: WB API should be extended to provide information about size and age of object.
Summary: Extend the WhiteBox API to provide information about the size and age of objects. Further add a mechanism to trigger a young GC.
Reviewed-by: tschatzl, sjohanss
Contributed-by: Leonid Mesnik <leonid.mesnik@oracle.com>
1 /*
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25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARKTHREAD_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARKTHREAD_HPP
28 #include "gc_implementation/shared/concurrentGCThread.hpp"
30 // The Concurrent Mark GC Thread (could be several in the future).
31 // This is copied from the Concurrent Mark Sweep GC Thread
32 // Still under construction.
34 class ConcurrentMark;
36 class ConcurrentMarkThread: public ConcurrentGCThread {
37 friend class VMStructs;
39 double _vtime_start; // Initial virtual time.
40 double _vtime_accum; // Accumulated virtual time.
42 double _vtime_mark_accum;
44 public:
45 virtual void run();
47 private:
48 ConcurrentMark* _cm;
49 volatile bool _started;
50 volatile bool _in_progress;
52 void sleepBeforeNextCycle();
54 static SurrogateLockerThread* _slt;
56 public:
57 // Constructor
58 ConcurrentMarkThread(ConcurrentMark* cm);
60 static void makeSurrogateLockerThread(TRAPS);
61 static SurrogateLockerThread* slt() { return _slt; }
63 // Printing
64 void print_on(outputStream* st) const;
65 void print() const;
67 // Total virtual time so far.
68 double vtime_accum();
69 // Marking virtual time so far
70 double vtime_mark_accum();
72 ConcurrentMark* cm() { return _cm; }
74 void set_started() { assert(!_in_progress, "cycle in progress"); _started = true; }
75 void clear_started() { assert(_in_progress, "must be starting a cycle"); _started = false; }
76 bool started() { return _started; }
78 void set_in_progress() { assert(_started, "must be starting a cycle"); _in_progress = true; }
79 void clear_in_progress() { assert(!_started, "must not be starting a new cycle"); _in_progress = false; }
80 bool in_progress() { return _in_progress; }
82 // This flag 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 this flag 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().
90 bool during_cycle() { return started() || in_progress(); }
92 // shutdown
93 void stop();
94 };
96 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTMARKTHREAD_HPP