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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

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 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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// Class CardGeneration is a generation that is covered by a card table,

// and uses a card-size block-offset array to implement block_start.

#include "gc/shared/generation.hpp"

class BlockOffsetSharedArray;

class CardTableRS;

class CompactibleSpace;

class CardGeneration: public Generation {

  friend class VMStructs;

 protected:

  // This is shared with other generations.

  CardTableRS* _rs;

  // This is local to this generation.

  BlockOffsetSharedArray* _bts;

  // Current shrinking effect: this damps shrinking when the heap gets empty.

  size_t _shrink_factor;

  size_t _min_heap_delta_bytes;   // Minimum amount to expand.

  // Some statistics from before gc started.

  // These are gathered in the gc_prologue (and should_collect)

  // to control growing/shrinking policy in spite of promotions.

  size_t _capacity_at_prologue;

  size_t _used_at_prologue;

  CardGeneration(ReservedSpace rs, size_t initial_byte_size, CardTableRS* remset);

  virtual void assert_correct_size_change_locking() = 0;

  virtual CompactibleSpace* space() const = 0;

 public:

  // Attempt to expand the generation by "bytes".  Expand by at a

  // minimum "expand_bytes".  Return true if some amount (not

  // necessarily the full "bytes") was done.

  virtual bool expand(size_t bytes, size_t expand_bytes);

  // Shrink generation with specified size

  virtual void shrink(size_t bytes);

  virtual void compute_new_size();

  virtual void clear_remembered_set();

  virtual void invalidate_remembered_set();

  virtual void prepare_for_verify();

  // Grow generation with specified size (returns false if unable to grow)

  bool grow_by(size_t bytes);

  // Grow generation to reserved size.

  bool grow_to_reserved();

  size_t capacity() const;

  size_t used() const;

  size_t free() const;

  MemRegion used_region() const;

  void space_iterate(SpaceClosure* blk, bool usedOnly = false);

  void younger_refs_iterate(OopsInGenClosure* blk, uint n_threads);

  bool is_in(const void* p) const;

  CompactibleSpace* first_compaction_space() const;

};