1 /*
   2  * Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_GC_G1_G1REGIONTOSPACEMAPPER_HPP
  26 #define SHARE_GC_G1_G1REGIONTOSPACEMAPPER_HPP
  27 
  28 #include "gc/g1/g1PageBasedVirtualSpace.hpp"
  29 #include "memory/allocation.hpp"
  30 #include "utilities/debug.hpp"
  31 
  32 class WorkGang;
  33 
  34 class G1MappingChangedListener {
  35  public:
  36   // Fired after commit of the memory, i.e. the memory this listener is registered
  37   // for can be accessed.
  38   // Zero_filled indicates that the memory can be considered as filled with zero bytes
  39   // when called.
  40   virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled) = 0;
  41 };
  42 
  43 // Maps region based commit/uncommit requests to the underlying page sized virtual
  44 // space.
  45 class G1RegionToSpaceMapper : public CHeapObj<mtGC> {
  46  private:
  47   G1MappingChangedListener* _listener;
  48  protected:
  49   // Backing storage.
  50   G1PageBasedVirtualSpace _storage;
  51 
  52   size_t _region_granularity;
  53   // Mapping management
  54   CHeapBitMap _commit_map;
  55 
  56   G1RegionToSpaceMapper(ReservedSpace rs, size_t used_size, size_t page_size, size_t region_granularity, size_t commit_factor, MemoryType type);
  57 
  58   void fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled);
  59  public:
  60   MemRegion reserved() { return _storage.reserved(); }
  61 
  62   size_t reserved_size() { return _storage.reserved_size(); }
  63   size_t committed_size() { return _storage.committed_size(); }
  64 
  65   void set_mapping_changed_listener(G1MappingChangedListener* listener) { _listener = listener; }
  66 
  67   virtual ~G1RegionToSpaceMapper() {}
  68 
  69   bool is_committed(uintptr_t idx) const {
  70     return _commit_map.at(idx);
  71   }
  72 
  73   void commit_and_set_special();
  74   virtual void commit_regions(uint start_idx, size_t num_regions = 1, WorkGang* pretouch_workers = NULL) = 0;
  75   virtual void uncommit_regions(uint start_idx, size_t num_regions = 1) = 0;
  76 
  77   // Creates an appropriate G1RegionToSpaceMapper for the given parameters.
  78   // The actual space to be used within the given reservation is given by actual_size.
  79   // This is because some OSes need to round up the reservation size to guarantee
  80   // alignment of page_size.
  81   // The byte_translation_factor defines how many bytes in a region correspond to
  82   // a single byte in the data structure this mapper is for.
  83   // Eg. in the card table, this value corresponds to the size a single card
  84   // table entry corresponds to in the heap.
  85   static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs,
  86                                               size_t actual_size,
  87                                               size_t page_size,
  88                                               size_t region_granularity,
  89                                               size_t byte_translation_factor,
  90                                               MemoryType type);
  91 
  92   static G1RegionToSpaceMapper* create_heap_mapper(ReservedSpace rs,
  93                                                    size_t actual_size,
  94                                                    size_t page_size,
  95                                                    size_t region_granularity,
  96                                                    size_t byte_translation_factor,
  97                                                    MemoryType type);
  98 };
  99 
 100 // G1RegionToSpaceMapper implementation where
 101 // part of space is mapped to dram and part to nv-dimm
 102 class G1RegionToHeteroSpaceMapper : public G1RegionToSpaceMapper {
 103 private:
 104   ReservedSpace _rs;
 105   G1RegionToSpaceMapper* _dram_mapper;
 106   uint _num_committed_dram;
 107   uint _num_committed_nvdimm;
 108   uint _start_index_of_dram;
 109   size_t _page_size;
 110   size_t _commit_factor;
 111   MemoryType _type;
 112 
 113 public:
 114   G1RegionToHeteroSpaceMapper(ReservedSpace rs, size_t used_size, size_t page_size, size_t region_granularity, size_t commit_factor, MemoryType type);
 115   bool initialize();
 116   uint num_committed_dram() const;
 117   uint num_committed_nvdimm() const;
 118 
 119   virtual void commit_regions(uint start_idx, size_t num_regions = 1, WorkGang* pretouch_workers = NULL);
 120   virtual void uncommit_regions(uint start_idx, size_t num_regions = 1);
 121 };
 122 #endif // SHARE_GC_G1_G1REGIONTOSPACEMAPPER_HPP