src/hotspot/share/gc/g1/g1ConcurrentMarkBitMap.hpp

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#ifndef SHARE_GC_G1_G1CONCURRENTMARKBITMAP_HPP
#define SHARE_GC_G1_G1CONCURRENTMARKBITMAP_HPP

#include "gc/g1/g1RegionToSpaceMapper.hpp"
#include "gc/shared/markBitMap.hpp"
#include "memory/memRegion.hpp"
#include "oops/oopsHierarchy.hpp"
#include "utilities/bitMap.hpp"
#include "utilities/globalDefinitions.hpp"
#include "utilities/macros.hpp"

class G1CMBitMap;
class G1CMTask;
class G1ConcurrentMark;
class HeapRegion;

// Closure for iteration over bitmaps
class G1CMBitMapClosure {
  G1ConcurrentMark* const _cm;
  G1CMTask* const _task;
public:
  G1CMBitMapClosure(G1CMTask *task, G1ConcurrentMark* cm) : _cm(cm), _task(task) { }

  bool do_addr(HeapWord* const addr);
};

class G1CMBitMapMappingChangedListener : public G1MappingChangedListener {
  G1CMBitMap* _bm;
public:
  G1CMBitMapMappingChangedListener() : _bm(NULL) {}

  void set_bitmap(G1CMBitMap* bm) { _bm = bm; }

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

// A generic mark bitmap for concurrent marking.  This is essentially a wrapper
// around the BitMap class that is based on HeapWords, with one bit per (1 << _shifter) HeapWords.
class G1CMBitMap : public MarkBitMap {

  G1CMBitMapMappingChangedListener _listener;

protected:

  virtual void check_mark(HeapWord* addr) NOT_DEBUG_RETURN;

public:

  G1CMBitMap() : MarkBitMap(), _listener() { _listener.set_bitmap(this); }

  // Initializes the underlying BitMap to cover the given area.
  void initialize(MemRegion heap, G1RegionToSpaceMapper* storage);

  // Apply the closure to the addresses that correspond to marked bits in the bitmap.
  inline bool iterate(G1CMBitMapClosure* cl, MemRegion mr);

  void clear_region(HeapRegion* hr);
};

#endif // SHARE_GC_G1_G1CONCURRENTMARKBITMAP_HPP