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 /*

  * Copyright (c) 2014, 2015, 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

  * or visit www.oracle.com if you need additional information or have any

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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 "memory/allocation.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.

   // Zero_filled indicates that the memory can be considered as filled with zero bytes

   // when called.

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

   // Mapping management

   BitMap _commit_map;

   G1RegionToSpaceMapper(ReservedSpace rs, size_t used_size, size_t page_size, size_t region_granularity, MemoryType type);

   void fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled);

  public:

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

   size_t reserved_size() { return _storage.reserved_size(); }

   size_t committed_size() { return _storage.committed_size(); }

   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(uint start_idx, size_t num_regions = 1) = 0;

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

   // Creates an appropriate G1RegionToSpaceMapper for the given parameters.

   // The actual space to be used within the given reservation is given by actual_size.

   // This is because some OSes need to round up the reservation size to guarantee

   // alignment of page_size.

   // 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 in the heap.

   static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs,

                                               size_t actual_size,

                                               size_t page_size,

                                               size_t region_granularity,

                                               size_t byte_translation_factor,

                                               MemoryType type);

 };

 #endif /* SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP */