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

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  43 class CodeBlobClosure;
  44 class G1CollectedHeap;
  45 class G1CMBitMap;
  46 class G1HotCardCache;
  47 class G1RemSetScanState;
  48 class G1ParScanThreadState;
  49 class G1Policy;
  50 class G1ScanObjsDuringScanRSClosure;
  51 class G1ScanObjsDuringUpdateRSClosure;
  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 public:
  71 
  72   typedef CardTable::CardValue CardValue;
  73   // Gives an approximation on how many threads can be expected to add records to
  74   // a remembered set in parallel. This can be used for sizing data structures to
  75   // decrease performance losses due to data structure sharing.
  76   // Examples for quantities that influence this value are the maximum number of
  77   // mutator threads, maximum number of concurrent refinement or GC threads.
  78   static uint num_par_rem_sets();
  79 
  80   // Initialize data that depends on the heap size being known.
  81   void initialize(size_t capacity, uint max_regions);
  82 
  83   G1RemSet(G1CollectedHeap* g1h,
  84            G1CardTable* ct,
  85            G1HotCardCache* hot_card_cache);
  86   ~G1RemSet();
  87 
  88   // Scan all remembered sets of the collection set for references into the collection
  89   // set.

  90   // Further applies heap_region_codeblobs on the oops of the unmarked nmethods on the strong code
  91   // roots list for each region in the collection set.
  92   void scan_rem_set(G1ParScanThreadState* pss,
  93                     uint worker_i,
  94                     G1GCPhaseTimes::GCParPhases scan_phase,
  95                     G1GCPhaseTimes::GCParPhases objcopy_phase,
  96                     G1GCPhaseTimes::GCParPhases coderoots_phase);
  97 
  98   // Flush remaining refinement buffers for cross-region references to either evacuate references
  99   // into the collection set or update the remembered set.
 100   void update_rem_set(G1ParScanThreadState* pss, uint worker_i);
 101 
 102   // Prepare for and cleanup after an oops_into_collection_set_do
 103   // call.  Must call each of these once before and after (in sequential
 104   // code) any thread calls oops_into_collection_set_do.
 105   void prepare_for_oops_into_collection_set_do();
 106   void cleanup_after_oops_into_collection_set_do();
 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, G1ScanObjsDuringUpdateRSClosure* update_rs_cl);
 119 
 120   // Print accumulated summary info from the start of the VM.


 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 class G1ScanRSForRegionClosure : public HeapRegionClosure {
 134   G1CollectedHeap* _g1h;
 135   G1CardTable *_ct;
 136 
 137   G1ParScanThreadState* _pss;
 138   G1ScanObjsDuringScanRSClosure* _scan_objs_on_card_cl;
 139 
 140   G1RemSetScanState* _scan_state;
 141 
 142   G1GCPhaseTimes::GCParPhases _phase;
 143 
 144   uint   _worker_i;
 145 
 146   size_t _opt_refs_scanned;
 147   size_t _opt_refs_memory_used;
 148 
 149   size_t _cards_scanned;
 150   size_t _cards_claimed;
 151   size_t _cards_skipped;
 152 
 153   Tickspan _rem_set_root_scan_time;
 154   Tickspan _rem_set_trim_partially_time;
 155 
 156   Tickspan _strong_code_root_scan_time;
 157   Tickspan _strong_code_trim_partially_time;
 158 
 159   void claim_card(size_t card_index, const uint region_idx_for_card);
 160   void scan_card(MemRegion mr, uint region_idx_for_card);
 161 
 162   void scan_opt_rem_set_roots(HeapRegion* r);
 163   void scan_rem_set_roots(HeapRegion* r);
 164   void scan_strong_code_roots(HeapRegion* r);
 165 public:
 166   G1ScanRSForRegionClosure(G1RemSetScanState* scan_state,
 167                            G1ScanObjsDuringScanRSClosure* scan_obj_on_card,
 168                            G1ParScanThreadState* pss,
 169                            G1GCPhaseTimes::GCParPhases phase,
 170                            uint worker_i);
 171 
 172   bool do_heap_region(HeapRegion* r);
 173 
 174   Tickspan rem_set_root_scan_time() const { return _rem_set_root_scan_time; }
 175   Tickspan rem_set_trim_partially_time() const { return _rem_set_trim_partially_time; }
 176 
 177   Tickspan strong_code_root_scan_time() const { return _strong_code_root_scan_time;  }
 178   Tickspan strong_code_root_trim_partially_time() const { return _strong_code_trim_partially_time; }
 179 
 180   size_t cards_scanned() const { return _cards_scanned; }
 181   size_t cards_claimed() const { return _cards_claimed; }
 182   size_t cards_skipped() const { return _cards_skipped; }
 183 
 184   size_t opt_refs_scanned() const { return _opt_refs_scanned; }
 185   size_t opt_refs_memory_used() const { return _opt_refs_memory_used; }
 186 };
 187 
 188 #endif // SHARE_GC_G1_G1REMSET_HPP


  43 class CodeBlobClosure;
  44 class G1CollectedHeap;
  45 class G1CMBitMap;
  46 class G1HotCardCache;
  47 class G1RemSetScanState;
  48 class G1ParScanThreadState;
  49 class G1Policy;
  50 class G1ScanObjsDuringScanRSClosure;
  51 class G1ScanObjsDuringUpdateRSClosure;
  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   // Scan all remembered sets of the collection set for references into the collection
  64   // set.
  65   void scan_rem_set(G1ParScanThreadState* pss, uint worker_i);
  66 
  67   // Flush remaining refinement buffers for cross-region references to either evacuate references
  68   // into the collection set or update the remembered set.
  69   void update_rem_set(G1ParScanThreadState* pss, uint worker_i);
  70 
  71   G1CollectedHeap* _g1h;
  72   size_t _num_conc_refined_cards; // Number of cards refined concurrently to the mutator.
  73 
  74   G1CardTable*           _ct;
  75   G1Policy*              _g1p;
  76   G1HotCardCache*        _hot_card_cache;
  77 
  78 public:
  79 
  80   typedef CardTable::CardValue CardValue;
  81   // Gives an approximation on how many threads can be expected to add records to
  82   // a remembered set in parallel. This can be used for sizing data structures to
  83   // decrease performance losses due to data structure sharing.
  84   // Examples for quantities that influence this value are the maximum number of
  85   // mutator threads, maximum number of concurrent refinement or GC threads.
  86   static uint num_par_rem_sets();
  87 
  88   // Initialize data that depends on the heap size being known.
  89   void initialize(size_t capacity, uint max_regions);
  90 
  91   G1RemSet(G1CollectedHeap* g1h,
  92            G1CardTable* ct,
  93            G1HotCardCache* hot_card_cache);
  94   ~G1RemSet();
  95 
  96   // Process all oops in the collection set from the cards in the refinement buffers and
  97   // remembered sets using pss.
  98   //
  99   // Further applies heap_region_codeblobs on the oops of the unmarked nmethods on the strong code
 100   // roots list for each region in the collection set.
 101   void oops_into_collection_set_do(G1ParScanThreadState* pss, uint worker_i);








 102 
 103   // Prepare for and cleanup after an oops_into_collection_set_do
 104   // call.  Must call each of these once before and after (in sequential
 105   // code) any thread calls oops_into_collection_set_do.
 106   void prepare_for_oops_into_collection_set_do();
 107   void cleanup_after_oops_into_collection_set_do();
 108 
 109   G1RemSetScanState* scan_state() const { return _scan_state; }
 110 
 111   // Refine the card corresponding to "card_ptr". Safe to be called concurrently
 112   // to the mutator.
 113   void refine_card_concurrently(CardValue* card_ptr,
 114                                 uint worker_i);
 115 
 116   // Refine the card corresponding to "card_ptr", applying the given closure to
 117   // all references found. Must only be called during gc.
 118   // Returns whether the card has been scanned.
 119   bool refine_card_during_gc(CardValue* card_ptr, G1ScanObjsDuringUpdateRSClosure* update_rs_cl);
 120 
 121   // Print accumulated summary info from the start of the VM.


 127   size_t num_conc_refined_cards() const { return _num_conc_refined_cards; }
 128 
 129   // Rebuilds the remembered set by scanning from bottom to TARS for all regions
 130   // using the given work gang.
 131   void rebuild_rem_set(G1ConcurrentMark* cm, WorkGang* workers, uint worker_id_offset);
 132 };
 133 
 134 class G1ScanRSForRegionClosure : public HeapRegionClosure {
 135   G1CollectedHeap* _g1h;
 136   G1CardTable *_ct;
 137 
 138   G1ParScanThreadState* _pss;
 139   G1ScanObjsDuringScanRSClosure* _scan_objs_on_card_cl;
 140 
 141   G1RemSetScanState* _scan_state;
 142 
 143   G1GCPhaseTimes::GCParPhases _phase;
 144 
 145   uint   _worker_i;
 146 



 147   size_t _cards_scanned;
 148   size_t _cards_claimed;
 149   size_t _cards_skipped;
 150 
 151   Tickspan _rem_set_root_scan_time;
 152   Tickspan _rem_set_trim_partially_time;
 153 
 154   Tickspan _strong_code_root_scan_time;
 155   Tickspan _strong_code_trim_partially_time;
 156 
 157   void claim_card(size_t card_index, const uint region_idx_for_card);
 158   void scan_card(MemRegion mr, uint region_idx_for_card);
 159 

 160   void scan_rem_set_roots(HeapRegion* r);
 161   void scan_strong_code_roots(HeapRegion* r);
 162 public:
 163   G1ScanRSForRegionClosure(G1RemSetScanState* scan_state,
 164                            G1ScanObjsDuringScanRSClosure* scan_obj_on_card,
 165                            G1ParScanThreadState* pss,
 166                            G1GCPhaseTimes::GCParPhases phase,
 167                            uint worker_i);
 168 
 169   bool do_heap_region(HeapRegion* r);
 170 
 171   Tickspan rem_set_root_scan_time() const { return _rem_set_root_scan_time; }
 172   Tickspan rem_set_trim_partially_time() const { return _rem_set_trim_partially_time; }
 173 
 174   Tickspan strong_code_root_scan_time() const { return _strong_code_root_scan_time;  }
 175   Tickspan strong_code_root_trim_partially_time() const { return _strong_code_trim_partially_time; }
 176 
 177   size_t cards_scanned() const { return _cards_scanned; }
 178   size_t cards_claimed() const { return _cards_claimed; }
 179   size_t cards_skipped() const { return _cards_skipped; }



 180 };
 181 
 182 #endif // SHARE_GC_G1_G1REMSET_HPP
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