/*

 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.

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

 *

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

 * under the terms of the GNU General Public License version 2 only, as

 * 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP

#define SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP

#include "gc_implementation/g1/g1PageBasedVirtualSpace.hpp"

#include "utilities/debug.hpp"

class G1MappingChangedListener VALUE_OBJ_CLASS_SPEC {

 public:

  // Fired after commit of the memory, i.e. the memory this listener is registered

  // for can be accessed.

  virtual void on_commit(uint start_idx, size_t num_regions) = 0;

};

// Maps region based commit/uncommit requests to the underlying page sized virtual

// space.

class G1RegionToSpaceMapper : public CHeapObj<mtGC> {

 private:

  G1MappingChangedListener* _listener;

 protected:

  // Backing storage.

  G1PageBasedVirtualSpace _storage;

  size_t _commit_granularity;

  size_t _region_granularity;

  // Mapping management

  BitMap _commit_map;

  G1RegionToSpaceMapper(ReservedSpace rs, size_t commit_granularity, size_t region_granularity, MemoryType type);

  void fire_on_commit(uint start_idx, size_t num_regions);

 public:

  MemRegion reserved() { return _storage.reserved(); }

  void set_mapping_changed_listener(G1MappingChangedListener* listener) { _listener = listener; }

  virtual ~G1RegionToSpaceMapper() {

    _commit_map.resize(0, /* in_resource_area */ false);

  }

  bool is_committed(uintptr_t idx) const {

    return _commit_map.at(idx);

  }

  virtual void commit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0;

  virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0;

  // Creates an appropriate G1RegionToSpaceMapper for the given parameters.

  // The byte_translation_factor defines how many bytes in a region correspond to

  // a single byte in the data structure this mapper is for.

  // Eg. in the card table, this value corresponds to the size a single card

  // table entry corresponds to.

  static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs,

                                              size_t os_commit_granularity,

                                              size_t region_granularity,

                                              size_t byte_translation_factor,

                                              MemoryType type);

};

#endif /* SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP */