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
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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 WorkGang;
33
34class G1MappingChangedListener VALUE_OBJ_CLASS_SPEC {
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.
45class 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  virtual void commit_regions(uint start_idx, size_t num_regions = 1, WorkGang* pretouch_workers = NULL) = 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