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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   MemoryType _memory_type;
57 
58   G1RegionToSpaceMapper(ReservedSpace rs, size_t used_size, size_t page_size, size_t region_granularity, size_t commit_factor, MemoryType type);
59 
60   void fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled);
61  public:
reserved()62   MemRegion reserved() { return _storage.reserved(); }
63 
reserved_size()64   size_t reserved_size() { return _storage.reserved_size(); }
committed_size()65   size_t committed_size() { return _storage.committed_size(); }
66 
set_mapping_changed_listener(G1MappingChangedListener * listener)67   void set_mapping_changed_listener(G1MappingChangedListener* listener) { _listener = listener; }
68 
~G1RegionToSpaceMapper()69   virtual ~G1RegionToSpaceMapper() {}
70 
is_committed(uintptr_t idx) const71   bool is_committed(uintptr_t idx) const {
72     return _commit_map.at(idx);
73   }
74 
75   void commit_and_set_special();
76   virtual void commit_regions(uint start_idx, size_t num_regions = 1, WorkGang* pretouch_workers = NULL) = 0;
77   virtual void uncommit_regions(uint start_idx, size_t num_regions = 1) = 0;
78 
79   // Creates an appropriate G1RegionToSpaceMapper for the given parameters.
80   // The actual space to be used within the given reservation is given by actual_size.
81   // This is because some OSes need to round up the reservation size to guarantee
82   // alignment of page_size.
83   // The byte_translation_factor defines how many bytes in a region correspond to
84   // a single byte in the data structure this mapper is for.
85   // Eg. in the card table, this value corresponds to the size a single card
86   // table entry corresponds to in the heap.
87   static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs,
88                                               size_t actual_size,
89                                               size_t page_size,
90                                               size_t region_granularity,
91                                               size_t byte_translation_factor,
92                                               MemoryType type);
93 
94   static G1RegionToSpaceMapper* create_heap_mapper(ReservedSpace rs,
95                                                    size_t actual_size,
96                                                    size_t page_size,
97                                                    size_t region_granularity,
98                                                    size_t byte_translation_factor,
99                                                    MemoryType type);
100 };
101 
102 // G1RegionToSpaceMapper implementation where
103 // part of space is mapped to dram and part to nv-dimm
104 class G1RegionToHeteroSpaceMapper : public G1RegionToSpaceMapper {
105 private:
106   ReservedSpace _rs;
107   G1RegionToSpaceMapper* _dram_mapper;
108   uint _num_committed_dram;
109   uint _num_committed_nvdimm;
110   uint _start_index_of_dram;
111   size_t _page_size;
112   size_t _commit_factor;
113   MemoryType _type;
114 
115 public:
116   G1RegionToHeteroSpaceMapper(ReservedSpace rs, size_t used_size, size_t page_size, size_t region_granularity, size_t commit_factor, MemoryType type);
117   bool initialize();
118   uint num_committed_dram() const;
119   uint num_committed_nvdimm() const;
120 
121   virtual void commit_regions(uint start_idx, size_t num_regions = 1, WorkGang* pretouch_workers = NULL);
122   virtual void uncommit_regions(uint start_idx, size_t num_regions = 1);
123 };
124 #endif // SHARE_GC_G1_G1REGIONTOSPACEMAPPER_HPP
125