1 /* 2 * Copyright (c) 2014, 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_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP 27 28 #include "gc_implementation/g1/g1PageBasedVirtualSpace.hpp" 29 #include "memory/allocation.hpp" 30 #include "utilities/debug.hpp" 31 32 class G1MappingChangedListener VALUE_OBJ_CLASS_SPEC { 33 public: 34 // Fired after commit of the memory, i.e. the memory this listener is registered 35 // for can be accessed. 36 // Zero_filled indicates that the memory can be considered as filled with zero bytes 37 // when called. 38 virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled) = 0; 39 }; 40 41 // Maps region based commit/uncommit requests to the underlying page sized virtual 42 // space. 43 class G1RegionToSpaceMapper : public CHeapObj<mtGC> { 44 private: 45 G1MappingChangedListener* _listener; 46 protected: 47 // Backing storage. 48 G1PageBasedVirtualSpace _storage; 49 size_t _commit_granularity; 50 size_t _region_granularity; 51 // Mapping management 52 BitMap _commit_map; 53 54 G1RegionToSpaceMapper(ReservedSpace rs, size_t commit_granularity, size_t region_granularity, MemoryType type); 55 56 void fire_on_commit(uint start_idx, size_t num_regions, bool zero_filled); 57 public: 58 MemRegion reserved() { return _storage.reserved(); } 59 60 void set_mapping_changed_listener(G1MappingChangedListener* listener) { _listener = listener; } 61 62 virtual ~G1RegionToSpaceMapper() { 63 _commit_map.resize(0, /* in_resource_area */ false); 64 } 65 66 bool is_committed(uintptr_t idx) const { 67 return _commit_map.at(idx); 68 } 69 70 virtual void commit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0; 71 virtual void uncommit_regions(uintptr_t start_idx, size_t num_regions = 1) = 0; 72 73 // Creates an appropriate G1RegionToSpaceMapper for the given parameters. 74 // The byte_translation_factor defines how many bytes in a region correspond to 75 // a single byte in the data structure this mapper is for. 76 // Eg. in the card table, this value corresponds to the size a single card 77 // table entry corresponds to. 78 static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs, 79 size_t os_commit_granularity, 80 size_t region_granularity, 81 size_t byte_translation_factor, 82 MemoryType type); 83 }; 84 85 #endif /* SHARE_VM_GC_IMPLEMENTATION_G1_G1REGIONTOSPACEMAPPER_HPP */