1 /*
 2  * Copyright (c) 2015, 2019, 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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22  */
23 
24 #ifndef SHARE_GC_Z_ZLIVEMAP_HPP
25 #define SHARE_GC_Z_ZLIVEMAP_HPP
26 
27 #include "gc/z/zBitMap.hpp"
28 #include "memory/allocation.hpp"
29 
30 class ObjectClosure;
31 
32 class ZLiveMap {
33   friend class ZLiveMapTest;
34 
35 private:
36   static const size_t nsegments = 64;
37 
38   volatile uint32_t _seqnum;
39   volatile uint32_t _live_objects;
40   volatile size_t   _live_bytes;
41   BitMap::bm_word_t _segment_live_bits;
42   BitMap::bm_word_t _segment_claim_bits;
43   ZBitMap           _bitmap;
44   size_t            _segment_shift;
45 
46   const BitMapView segment_live_bits() const;
47   const BitMapView segment_claim_bits() const;
48 
49   BitMapView segment_live_bits();
50   BitMapView segment_claim_bits();
51 
52   BitMap::idx_t segment_size() const;
53 
54   BitMap::idx_t segment_start(BitMap::idx_t segment) const;
55   BitMap::idx_t segment_end(BitMap::idx_t segment) const;
56 
57   bool is_segment_live(BitMap::idx_t segment) const;
58   bool set_segment_live_atomic(BitMap::idx_t segment);
59 
60   BitMap::idx_t first_live_segment() const;
61   BitMap::idx_t next_live_segment(BitMap::idx_t segment) const;
62   BitMap::idx_t index_to_segment(BitMap::idx_t index) const;
63 
64   bool claim_segment(BitMap::idx_t segment);
65 
66   void reset(size_t index);
67   void reset_segment(BitMap::idx_t segment);
68 
69   void iterate_segment(ObjectClosure* cl, BitMap::idx_t segment, uintptr_t page_start, size_t page_object_alignment_shift);
70 
71 public:
72   ZLiveMap(uint32_t size);
73 
74   void reset();
75   void resize(uint32_t size);
76 
77   bool is_marked() const;
78 
79   uint32_t live_objects() const;
80   size_t live_bytes() const;
81 
82   bool get(size_t index) const;
83   bool set_atomic(size_t index, bool finalizable, bool& inc_live);
84 
85   void inc_live_atomic(uint32_t objects, size_t bytes);
86 
87   void iterate(ObjectClosure* cl, uintptr_t page_start, size_t page_object_alignment_shift);
88 };
89 
90 #endif // SHARE_GC_Z_ZLIVEMAP_HPP