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src/hotspot/share/gc/g1/g1RemSet.hpp

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  29 #include "gc/g1/g1OopClosures.hpp"
  30 #include "gc/g1/g1GCPhaseTimes.hpp"
  31 #include "gc/g1/g1RemSetSummary.hpp"
  32 #include "gc/g1/heapRegion.hpp"
  33 #include "memory/allocation.hpp"
  34 #include "memory/iterator.hpp"
  35 #include "utilities/ticks.hpp"
  36 
  37 // A G1RemSet provides ways of iterating over pointers into a selected
  38 // collection set.
  39 
  40 class BitMap;
  41 class CardTableBarrierSet;
  42 class G1BlockOffsetTable;
  43 class CodeBlobClosure;
  44 class G1CollectedHeap;
  45 class G1CMBitMap;
  46 class G1HotCardCache;
  47 class G1RemSetScanState;
  48 class G1ParScanThreadState;
  49 class G1ParScanThreadStateSet;
  50 class G1Policy;
  51 class G1ScanCardClosure;
  52 class HeapRegionClaimer;
  53 
  54 // A G1RemSet in which each heap region has a rem set that records the
  55 // external heap references into it.  Uses a mod ref bs to track updates,
  56 // so that they can be used to update the individual region remsets.
  57 class G1RemSet: public CHeapObj<mtGC> {
  58 private:
  59   G1RemSetScanState* _scan_state;
  60 
  61   G1RemSetSummary _prev_period_summary;
  62 
  63   G1CollectedHeap* _g1h;
  64   size_t _num_conc_refined_cards; // Number of cards refined concurrently to the mutator.
  65 
  66   G1CardTable*           _ct;
  67   G1Policy*              _g1p;
  68   G1HotCardCache*        _hot_card_cache;
  69 
  70   void print_merge_heap_roots_stats();
  71 public:
  72 
  73   typedef CardTable::CardValue CardValue;
  74   // Gives an approximation on how many threads can be expected to add records to
  75   // a remembered set in parallel. This can be used for sizing data structures to
  76   // decrease performance losses due to data structure sharing.
  77   // Examples for quantities that influence this value are the maximum number of
  78   // mutator threads, maximum number of concurrent refinement or GC threads.
  79   static uint num_par_rem_sets();
  80 
  81   // Initialize data that depends on the heap size being known.
  82   void initialize(size_t capacity, uint max_regions);
  83 
  84   G1RemSet(G1CollectedHeap* g1h,
  85            G1CardTable* ct,
  86            G1HotCardCache* hot_card_cache);
  87   ~G1RemSet();
  88 
  89   // Scan all cards in the non-collection set regions that potentially contain
  90   // references into the current whole collection set.
  91   void scan_heap_roots(G1ParScanThreadState* pss,
  92                        uint worker_id,
  93                        G1GCPhaseTimes::GCParPhases scan_phase,
  94                        G1GCPhaseTimes::GCParPhases objcopy_phase);
  95 
  96   // Merge cards from various sources (remembered sets, hot card cache, log buffers)
  97   // and calculate the cards that need to be scanned later (via scan_heap_roots()).
  98   // If initial_evacuation is set, this is called during the initial evacuation.
  99   void merge_heap_roots(bool initial_evacuation);


 100 
 101   // Prepare for and cleanup after scanning the heap roots. Must be called
 102   // once before and after in sequential code.
 103   void prepare_for_scan_heap_roots();
 104   // Cleans the card table from temporary duplicate detection information.
 105   void cleanup_after_scan_heap_roots();
 106   // Prepares the given region for heap root scanning.
 107   void prepare_for_scan_heap_roots(uint region_idx);
 108 
 109   // Do work for regions in the current increment of the collection set, scanning
 110   // non-card based (heap) roots.
 111   void scan_collection_set_regions(G1ParScanThreadState* pss,
 112                                    uint worker_id,
 113                                    G1GCPhaseTimes::GCParPhases scan_phase,
 114                                    G1GCPhaseTimes::GCParPhases coderoots_phase,
 115                                    G1GCPhaseTimes::GCParPhases objcopy_phase);
 116 
 117   // Refine the card corresponding to "card_ptr". Safe to be called concurrently
 118   // to the mutator.
 119   void refine_card_concurrently(CardValue* card_ptr,
 120                                 uint worker_i);





 121 
 122   // Print accumulated summary info from the start of the VM.
 123   void print_summary_info();
 124 
 125   // Print accumulated summary info from the last time called.
 126   void print_periodic_summary_info(const char* header, uint period_count);
 127 
 128   size_t num_conc_refined_cards() const { return _num_conc_refined_cards; }
 129 
 130   // Rebuilds the remembered set by scanning from bottom to TARS for all regions
 131   // using the given work gang.
 132   void rebuild_rem_set(G1ConcurrentMark* cm, WorkGang* workers, uint worker_id_offset);
 133 };
 134 
 135 #endif // SHARE_GC_G1_G1REMSET_HPP


  29 #include "gc/g1/g1OopClosures.hpp"
  30 #include "gc/g1/g1GCPhaseTimes.hpp"
  31 #include "gc/g1/g1RemSetSummary.hpp"
  32 #include "gc/g1/heapRegion.hpp"
  33 #include "memory/allocation.hpp"
  34 #include "memory/iterator.hpp"
  35 #include "utilities/ticks.hpp"
  36 
  37 // A G1RemSet provides ways of iterating over pointers into a selected
  38 // collection set.
  39 
  40 class BitMap;
  41 class CardTableBarrierSet;
  42 class G1BlockOffsetTable;
  43 class CodeBlobClosure;
  44 class G1CollectedHeap;
  45 class G1CMBitMap;
  46 class G1HotCardCache;
  47 class G1RemSetScanState;
  48 class G1ParScanThreadState;

  49 class G1Policy;
  50 class G1ScanCardClosure;
  51 class HeapRegionClaimer;
  52 
  53 // A G1RemSet in which each heap region has a rem set that records the
  54 // external heap references into it.  Uses a mod ref bs to track updates,
  55 // so that they can be used to update the individual region remsets.
  56 class G1RemSet: public CHeapObj<mtGC> {
  57 private:
  58   G1RemSetScanState* _scan_state;
  59 
  60   G1RemSetSummary _prev_period_summary;
  61 
  62   G1CollectedHeap* _g1h;
  63   size_t _num_conc_refined_cards; // Number of cards refined concurrently to the mutator.
  64 
  65   G1CardTable*           _ct;
  66   G1Policy*              _g1p;
  67   G1HotCardCache*        _hot_card_cache;
  68 

  69 public:
  70 
  71   typedef CardTable::CardValue CardValue;
  72   // Gives an approximation on how many threads can be expected to add records to
  73   // a remembered set in parallel. This can be used for sizing data structures to
  74   // decrease performance losses due to data structure sharing.
  75   // Examples for quantities that influence this value are the maximum number of
  76   // mutator threads, maximum number of concurrent refinement or GC threads.
  77   static uint num_par_rem_sets();
  78 
  79   // Initialize data that depends on the heap size being known.
  80   void initialize(size_t capacity, uint max_regions);
  81 
  82   G1RemSet(G1CollectedHeap* g1h,
  83            G1CardTable* ct,
  84            G1HotCardCache* hot_card_cache);
  85   ~G1RemSet();
  86 
  87   // Scan all remembered sets of the collection set for references into the collection
  88   // set.
  89   // Further applies heap_region_codeblobs on the oops of the unmarked nmethods on the strong code
  90   // roots list for each region in the collection set.
  91   void scan_rem_set(G1ParScanThreadState* pss,
  92                     uint worker_i,
  93                     G1GCPhaseTimes::GCParPhases scan_phase,
  94                     G1GCPhaseTimes::GCParPhases objcopy_phase,
  95                     G1GCPhaseTimes::GCParPhases coderoots_phase);
  96 
  97   // Flush remaining refinement buffers for cross-region references to either evacuate references
  98   // into the collection set or update the remembered set.
  99   void update_rem_set(G1ParScanThreadState* pss, uint worker_i);
 100 
 101   // Prepare for and cleanup after scanning the remembered sets. Must be called
 102   // once before and after in sequential code.
 103   void prepare_for_scan_rem_set();
 104   void cleanup_after_scan_rem_set();
 105   // Prepares the given region for remembered set scanning.
 106   void prepare_for_scan_rem_set(uint region_idx);
 107 
 108   G1RemSetScanState* scan_state() const { return _scan_state; }







 109 
 110   // Refine the card corresponding to "card_ptr". Safe to be called concurrently
 111   // to the mutator.
 112   void refine_card_concurrently(CardValue* card_ptr,
 113                                 uint worker_i);
 114 
 115   // Refine the card corresponding to "card_ptr", applying the given closure to
 116   // all references found. Must only be called during gc.
 117   // Returns whether the card has been scanned.
 118   bool refine_card_during_gc(CardValue* card_ptr, G1ScanCardClosure* update_rs_cl);
 119 
 120   // Print accumulated summary info from the start of the VM.
 121   void print_summary_info();
 122 
 123   // Print accumulated summary info from the last time called.
 124   void print_periodic_summary_info(const char* header, uint period_count);
 125 
 126   size_t num_conc_refined_cards() const { return _num_conc_refined_cards; }
 127 
 128   // Rebuilds the remembered set by scanning from bottom to TARS for all regions
 129   // using the given work gang.
 130   void rebuild_rem_set(G1ConcurrentMark* cm, WorkGang* workers, uint worker_id_offset);
 131 };
 132 
 133 #endif // SHARE_GC_G1_G1REMSET_HPP
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