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

rev 52310 : imported patch 8071913-almost-done
rev 52314 : imported patch 8211388-make-otherregionstable-unaware-of-to-region
rev 52315 : imported patch 8211388-sangheon-review

*** 74,84 ****
  class OtherRegionsTable {
    friend class HeapRegionRemSetIterator;
  
    G1CollectedHeap* _g1h;
    Mutex*           _m;
-   HeapRegion*      _hr;
  
    // These are protected by "_m".
    CHeapBitMap _coarse_map;
    size_t      _n_coarse_entries;
    static jint _n_coarsenings;
--- 74,83 ----
*** 122,136 ****
    void unlink_from_all(PerRegionTable * prt);
  
    bool contains_reference_locked(OopOrNarrowOopStar from) const;
  
  public:
!   // Clear the from_card_cache entries for this region.
!   void clear_fcc();
!   // Create a new remembered set for the given heap region. The given mutex should
!   // be used to ensure consistency.
!   OtherRegionsTable(HeapRegion* hr, Mutex* m);
  
    // Returns the card index of the given within_region pointer relative to the bottom
    // of the given heap region.
    static CardIdx_t card_within_region(OopOrNarrowOopStar within_region, HeapRegion* hr);
    // Adds the reference from "from to this remembered set.
--- 121,132 ----
    void unlink_from_all(PerRegionTable * prt);
  
    bool contains_reference_locked(OopOrNarrowOopStar from) const;
  
  public:
!   // Create a new remembered set. The given mutex is used to ensure consistency.
!   OtherRegionsTable(Mutex* m);
  
    // Returns the card index of the given within_region pointer relative to the bottom
    // of the given heap region.
    static CardIdx_t card_within_region(OopOrNarrowOopStar within_region, HeapRegion* hr);
    // Adds the reference from "from to this remembered set.
*** 180,189 ****
--- 176,189 ----
  
    Mutex _m;
  
    OtherRegionsTable _other_regions;
  
+   HeapRegion* _hr;
+ 
+   void clear_fcc();
+ 
  public:
    HeapRegionRemSet(G1BlockOffsetTable* bot, HeapRegion* hr);
  
    static void setup_remset_size();
  
*** 241,262 ****
    void set_state_empty() {
      guarantee(SafepointSynchronize::is_at_safepoint() || !is_tracked(), "Should only set to Untracked during safepoint but is %s.", get_state_str());
      if (_state == Untracked) {
        return;
      }
!     _other_regions.clear_fcc();
      _state = Untracked;
    }
  
    void set_state_updating() {
      guarantee(SafepointSynchronize::is_at_safepoint() && !is_tracked(), "Should only set to Updating from Untracked during safepoint but is %s", get_state_str());
!     _other_regions.clear_fcc();
      _state = Updating;
    }
  
    void set_state_complete() {
!     _other_regions.clear_fcc();
      _state = Complete;
    }
  
    // Used in the sequential case.
    void add_reference(OopOrNarrowOopStar from) {
--- 241,262 ----
    void set_state_empty() {
      guarantee(SafepointSynchronize::is_at_safepoint() || !is_tracked(), "Should only set to Untracked during safepoint but is %s.", get_state_str());
      if (_state == Untracked) {
        return;
      }
!     clear_fcc();
      _state = Untracked;
    }
  
    void set_state_updating() {
      guarantee(SafepointSynchronize::is_at_safepoint() && !is_tracked(), "Should only set to Updating from Untracked during safepoint but is %s", get_state_str());
!     clear_fcc();
      _state = Updating;
    }
  
    void set_state_complete() {
!     clear_fcc();
      _state = Complete;
    }
  
    // Used in the sequential case.
    void add_reference(OopOrNarrowOopStar from) {
*** 267,276 ****
--- 267,285 ----
    void add_reference(OopOrNarrowOopStar from, uint tid) {
      RemSetState state = _state;
      if (state == Untracked) {
        return;
      }
+ 
+     uint cur_idx = _hr->hrm_index();
+     uintptr_t from_card = uintptr_t(from) >> CardTable::card_shift;
+ 
+     if (G1FromCardCache::contains_or_replace(tid, cur_idx, from_card)) {
+       assert(contains_reference(from), "We just found " PTR_FORMAT " in the FromCardCache", p2i(from));
+       return;
+     }
+ 
      _other_regions.add_reference(from, tid);
    }
  
    // The region is being reclaimed; clear its remset, and any mention of
    // entries for this region in other remsets.