1/*
2 * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24#ifndef SHARE_GC_SHENANDOAH_SHENANDOAHMARKINGCONTEXT_HPP
25#define SHARE_GC_SHENANDOAH_SHENANDOAHMARKINGCONTEXT_HPP
26
27#include "gc/shared/markBitMap.hpp"
28#include "memory/allocation.hpp"
29#include "memory/memRegion.hpp"
30#include "oops/oopsHierarchy.hpp"
31
32/**
33 * Encapsulate a marking bitmap with the top-at-mark-start and top-bitmaps array.
34 */
35class ShenandoahMarkingContext : public CHeapObj<mtGC> {
36private:
37 MarkBitMap _mark_bit_map;
38
39 HeapWord** const _top_bitmaps;
40 HeapWord** const _top_at_mark_starts_base;
41 HeapWord** const _top_at_mark_starts;
42
43 ShenandoahSharedFlag _is_complete;
44
45public:
46 ShenandoahMarkingContext(MemRegion heap_region, MemRegion bitmap_region, size_t num_regions);
47
48 /*
49 * Marks the object. Returns true if the object has not been marked before and has
50 * been marked by this thread. Returns false if the object has already been marked,
51 * or if a competing thread succeeded in marking this object.
52 */
53 inline bool mark(oop obj);
54
55 inline bool is_marked(oop obj) const;
56
57 inline bool allocated_after_mark_start(HeapWord* addr) const;
58
59 inline MarkBitMap* mark_bit_map();
60
61 HeapWord* top_at_mark_start(ShenandoahHeapRegion* r) const;
62 void capture_top_at_mark_start(ShenandoahHeapRegion* r);
63 void reset_top_at_mark_start(ShenandoahHeapRegion* r);
64 void initialize_top_at_mark_start(ShenandoahHeapRegion* r);
65
66 void reset_top_bitmap(ShenandoahHeapRegion *r);
67 void clear_bitmap(ShenandoahHeapRegion *r);
68
69 bool is_bitmap_clear() const;
70 bool is_bitmap_clear_range(HeapWord* start, HeapWord* end) const;
71
72 bool is_complete();
73 void mark_complete();
74 void mark_incomplete();
75
76};
77
78#endif // SHARE_GC_SHENANDOAH_SHENANDOAHMARKINGCONTEXT_HPP
79