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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

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#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1CARDCOUNTS_HPP

#define SHARE_VM_GC_IMPLEMENTATION_G1_G1CARDCOUNTS_HPP

#include "gc_implementation/g1/g1RegionToSpaceMapper.hpp"

#include "memory/allocation.hpp"

#include "runtime/virtualspace.hpp"

#include "utilities/globalDefinitions.hpp"

class CardTableModRefBS;

class G1CardCounts;

class G1CollectedHeap;

class G1RegionToSpaceMapper;

class HeapRegion;

class G1CardCountsMappingChangedListener : public G1MappingChangedListener {

 private:

  G1CardCounts* _counts;

 public:

  void set_cardcounts(G1CardCounts* counts) { _counts = counts; }

  virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled);

};

// Table to track the number of times a card has been refined. Once

// a card has been refined a certain number of times, it is

// considered 'hot' and its refinement is delayed by inserting the

// card into the hot card cache. The card will then be refined when

// it is evicted from the hot card cache, or when the hot card cache

// is 'drained' during the next evacuation pause.

class G1CardCounts: public CHeapObj<mtGC> {

  G1CardCountsMappingChangedListener _listener;

  G1CollectedHeap* _g1h;

  // The table of counts

  jubyte* _card_counts;

  // Max capacity of the reserved space for the counts table

  size_t _reserved_max_card_num;

  // CardTable bottom.

  const jbyte* _ct_bot;

  // Barrier set

  CardTableModRefBS* _ct_bs;

  // Returns true if the card counts table has been reserved.

  bool has_reserved_count_table() { return _card_counts != NULL; }

  // Returns true if the card counts table has been reserved and committed.

  bool has_count_table() {

    return has_reserved_count_table();

  }

  size_t ptr_2_card_num(const jbyte* card_ptr) {

    assert(card_ptr >= _ct_bot,

           err_msg("Invalid card pointer: "

                   "card_ptr: " PTR_FORMAT ", "

                   "_ct_bot: " PTR_FORMAT,

                   p2i(card_ptr), p2i(_ct_bot)));

    size_t card_num = pointer_delta(card_ptr, _ct_bot, sizeof(jbyte));

           err_msg("card pointer out of range: " PTR_FORMAT, p2i(card_ptr)));

    return card_num;

  }

  jbyte* card_num_2_ptr(size_t card_num) {

           err_msg("card num out of range: "SIZE_FORMAT, card_num));

    return (jbyte*) (_ct_bot + card_num);

  }

  // Clear the counts table for the given (exclusive) index range.

  void clear_range(size_t from_card_num, size_t to_card_num);

 public:

  G1CardCounts(G1CollectedHeap* g1h);

  void initialize(G1RegionToSpaceMapper* mapper);

  // Increments the refinement count for the given card.

  // Returns the pre-increment count value.

  uint add_card_count(jbyte* card_ptr);

  // Returns true if the given count is high enough to be considered

  // 'hot'; false otherwise.

  bool is_hot(uint count);

  // Clears the card counts for the cards spanned by the region

  void clear_region(HeapRegion* hr);

  // Clears the card counts for the cards spanned by the MemRegion

  void clear_range(MemRegion mr);

  // Clear the entire card counts table during GC.

  void clear_all();

};

#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1CARDCOUNTS_HPP