g1RegionToSpaceMapper.hpp revision 8413:92457dfb91bd
1/* 2 * Copyright (c) 2014, 2015, 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_G1_G1REGIONTOSPACEMAPPER_HPP 26#define SHARE_VM_GC_G1_G1REGIONTOSPACEMAPPER_HPP 27 28#include "gc/g1/g1PageBasedVirtualSpace.hpp" 29#include "memory/allocation.hpp" 30#include "utilities/debug.hpp" 31 32class 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. 43class G1RegionToSpaceMapper : public CHeapObj<mtGC> { 44 private: 45 G1MappingChangedListener* _listener; 46 protected: 47 // Backing storage. 48 G1PageBasedVirtualSpace _storage; 49 50 size_t _region_granularity; 51 // Mapping management 52 BitMap _commit_map; 53 54 G1RegionToSpaceMapper(ReservedSpace rs, size_t used_size, size_t page_size, 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 size_t reserved_size() { return _storage.reserved_size(); } 61 size_t committed_size() { return _storage.committed_size(); } 62 63 void set_mapping_changed_listener(G1MappingChangedListener* listener) { _listener = listener; } 64 65 virtual ~G1RegionToSpaceMapper() { 66 _commit_map.resize(0, /* in_resource_area */ false); 67 } 68 69 bool is_committed(uintptr_t idx) const { 70 return _commit_map.at(idx); 71 } 72 73 virtual void commit_regions(uint start_idx, size_t num_regions = 1) = 0; 74 virtual void uncommit_regions(uint start_idx, size_t num_regions = 1) = 0; 75 76 // Creates an appropriate G1RegionToSpaceMapper for the given parameters. 77 // The actual space to be used within the given reservation is given by actual_size. 78 // This is because some OSes need to round up the reservation size to guarantee 79 // alignment of page_size. 80 // The byte_translation_factor defines how many bytes in a region correspond to 81 // a single byte in the data structure this mapper is for. 82 // Eg. in the card table, this value corresponds to the size a single card 83 // table entry corresponds to in the heap. 84 static G1RegionToSpaceMapper* create_mapper(ReservedSpace rs, 85 size_t actual_size, 86 size_t page_size, 87 size_t region_granularity, 88 size_t byte_translation_factor, 89 MemoryType type); 90}; 91 92#endif /* SHARE_VM_GC_G1_G1REGIONTOSPACEMAPPER_HPP */ 93