1 /*
2 * Copyright (c) 2015, 2026, 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 #ifndef SHARE_GC_Z_ZLIVEMAP_HPP
25 #define SHARE_GC_Z_ZLIVEMAP_HPP
26
27 #include "gc/z/zAddress.hpp"
28 #include "gc/z/zBitMap.hpp"
29 #include "gc/z/zGenerationId.hpp"
30 #include "memory/allocation.hpp"
31 #include "runtime/atomic.hpp"
32
33 class ObjectClosure;
34
35 class ZLiveMap {
36 friend class ZLiveMapTest;
37
38 private:
39 static const uint32_t NumSegments = 64;
40 static const uint32_t BitsPerObject = 2;
41
42 const uint32_t _segment_size;
43 const int _segment_shift;
44
45 Atomic<uint32_t> _seqnum;
46 Atomic<uint32_t> _live_objects;
47 Atomic<size_t> _live_bytes;
48 BitMap::bm_word_t _segment_live_bits;
49 BitMap::bm_word_t _segment_claim_bits;
50 ZBitMap _bitmap;
51
52 const BitMapView segment_live_bits() const;
53 const BitMapView segment_claim_bits() const;
54
55 BitMapView segment_live_bits();
56 BitMapView segment_claim_bits();
57
58 BitMap::idx_t segment_start(BitMap::idx_t segment) const;
59 BitMap::idx_t segment_end(BitMap::idx_t segment) const;
60
61 bool is_segment_live(BitMap::idx_t segment) const;
62 bool set_segment_live(BitMap::idx_t segment);
63
64 BitMap::idx_t first_live_segment() const;
65 BitMap::idx_t next_live_segment(BitMap::idx_t segment) const;
66 BitMap::idx_t index_to_segment(BitMap::idx_t index) const;
67
68 bool claim_segment(BitMap::idx_t segment);
69
70 void initialize_bitmap();
71
72 void reset(ZGenerationId id);
73 void reset_segment(BitMap::idx_t segment);
74
75 size_t do_object(ObjectClosure* cl, zaddress addr) const;
76
77 template <typename Function>
78 void iterate_segment(BitMap::idx_t segment, Function function);
79
80 public:
81 ZLiveMap(uint32_t object_max_count);
82 ZLiveMap(const ZLiveMap& other) = delete;
83
84 void reset();
85
86 bool is_marked(ZGenerationId id) const;
87
88 uint32_t live_objects() const;
89 size_t live_bytes() const;
90
91 bool get(ZGenerationId id, BitMap::idx_t index) const;
92 bool set(ZGenerationId id, BitMap::idx_t index, bool finalizable, bool& inc_live);
93
94 void inc_live(uint32_t objects, size_t bytes);
95
96 template <typename Function>
97 void iterate(ZGenerationId id, Function function);
98
99 BitMap::idx_t find_base_bit(BitMap::idx_t index);
100 BitMap::idx_t find_base_bit_in_segment(BitMap::idx_t start, BitMap::idx_t index);
101 };
102
103 #endif // SHARE_GC_Z_ZLIVEMAP_HPP