1/*
2 * Copyright (c) 2017, 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.
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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_G1CONCURRENTMARKBITMAP_HPP
26#define SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_HPP
27
28#include "gc/g1/g1RegionToSpaceMapper.hpp"
29#include "memory/allocation.hpp"
30#include "memory/memRegion.hpp"
31#include "utilities/bitMap.hpp"
32#include "utilities/globalDefinitions.hpp"
33#include "utilities/macros.hpp"
34
35class G1CMBitMap;
36class G1CMTask;
37class G1ConcurrentMark;
38
39// Closure for iteration over bitmaps
40class G1CMBitMapClosure VALUE_OBJ_CLASS_SPEC {
41private:
42  G1ConcurrentMark* const _cm;
43  G1CMTask* const _task;
44public:
45  G1CMBitMapClosure(G1CMTask *task, G1ConcurrentMark* cm) : _task(task), _cm(cm) { }
46
47  bool do_addr(HeapWord* const addr);
48};
49
50class G1CMBitMapMappingChangedListener : public G1MappingChangedListener {
51 private:
52  G1CMBitMap* _bm;
53 public:
54  G1CMBitMapMappingChangedListener() : _bm(NULL) {}
55
56  void set_bitmap(G1CMBitMap* bm) { _bm = bm; }
57
58  virtual void on_commit(uint start_idx, size_t num_regions, bool zero_filled);
59};
60
61// A generic mark bitmap for concurrent marking.  This is essentially a wrapper
62// around the BitMap class that is based on HeapWords, with one bit per (1 << _shifter) HeapWords.
63class G1CMBitMap VALUE_OBJ_CLASS_SPEC {
64private:
65  MemRegion _covered;    // The heap area covered by this bitmap.
66
67  const int _shifter;    // Shift amount from heap index to bit index in the bitmap.
68
69  BitMapView _bm;        // The actual bitmap.
70
71  G1CMBitMapMappingChangedListener _listener;
72
73  inline void check_mark(HeapWord* addr) NOT_DEBUG_RETURN;
74
75  // Convert from bit offset to address.
76  HeapWord* offset_to_addr(size_t offset) const {
77    return _covered.start() + (offset << _shifter);
78  }
79  // Convert from address to bit offset.
80  size_t addr_to_offset(const HeapWord* addr) const {
81    return pointer_delta(addr, _covered.start()) >> _shifter;
82  }
83public:
84  static size_t compute_size(size_t heap_size);
85  // Returns the amount of bytes on the heap between two marks in the bitmap.
86  static size_t mark_distance();
87  // Returns how many bytes (or bits) of the heap a single byte (or bit) of the
88  // mark bitmap corresponds to. This is the same as the mark distance above.
89  static size_t heap_map_factor() {
90    return mark_distance();
91  }
92
93  G1CMBitMap() : _covered(), _bm(), _shifter(LogMinObjAlignment), _listener() { _listener.set_bitmap(this); }
94
95  // Initializes the underlying BitMap to cover the given area.
96  void initialize(MemRegion heap, G1RegionToSpaceMapper* storage);
97
98  // Read marks
99  bool is_marked(HeapWord* addr) const {
100    assert(_covered.contains(addr),
101           "Address " PTR_FORMAT " is outside underlying space from " PTR_FORMAT " to " PTR_FORMAT,
102           p2i(addr), p2i(_covered.start()), p2i(_covered.end()));
103    return _bm.at(addr_to_offset(addr));
104  }
105
106  // Apply the closure to the addresses that correspond to marked bits in the bitmap.
107  inline bool iterate(G1CMBitMapClosure* cl, MemRegion mr);
108
109  // Return the address corresponding to the next marked bit at or after
110  // "addr", and before "limit", if "limit" is non-NULL.  If there is no
111  // such bit, returns "limit" if that is non-NULL, or else "endWord()".
112  inline HeapWord* get_next_marked_addr(const HeapWord* addr,
113                                        const HeapWord* limit) const;
114
115  // The argument addr should be the start address of a valid object
116  inline HeapWord* addr_after_obj(HeapWord* addr);
117
118  void print_on_error(outputStream* st, const char* prefix) const;
119
120  // Write marks.
121  inline void mark(HeapWord* addr);
122  inline void clear(HeapWord* addr);
123  inline bool par_mark(HeapWord* addr);
124
125  void clear_range(MemRegion mr);
126};
127
128#endif // SHARE_VM_GC_G1_G1CONCURRENTMARKBITMAP_HPP
129