1 /*
2 * Copyright (c) 2018, 2021, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "precompiled.hpp"
27 #include "gc/shared/markBitMap.inline.hpp"
28 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
29 #include "gc/shenandoah/shenandoahMarkingContext.hpp"
30
31 ShenandoahMarkingContext::ShenandoahMarkingContext(MemRegion heap_region, MemRegion bitmap_region, size_t num_regions) :
32 _mark_bit_map(heap_region, bitmap_region),
33 _top_bitmaps(NEW_C_HEAP_ARRAY(HeapWord*, num_regions, mtGC)),
34 _top_at_mark_starts_base(NEW_C_HEAP_ARRAY(HeapWord*, num_regions, mtGC)),
35 _top_at_mark_starts(_top_at_mark_starts_base -
36 ((uintx) heap_region.start() >> ShenandoahHeapRegion::region_size_bytes_shift())) {
37 }
38
39 bool ShenandoahMarkingContext::is_bitmap_clear() const {
40 ShenandoahHeap* heap = ShenandoahHeap::heap();
41 size_t num_regions = heap->num_regions();
42 for (size_t idx = 0; idx < num_regions; idx++) {
43 ShenandoahHeapRegion* r = heap->get_region(idx);
44 if (r->is_affiliated() && heap->is_bitmap_slice_committed(r)
45 && !is_bitmap_range_within_region_clear(r->bottom(), r->end())) {
46 return false;
47 }
48 }
49 return true;
50 }
51
52 bool ShenandoahMarkingContext::is_bitmap_range_within_region_clear(const HeapWord* start, const HeapWord* end) const {
53 assert(start <= end, "Invalid start " PTR_FORMAT " and end " PTR_FORMAT, p2i(start), p2i(end));
54 if (start < end) {
55 ShenandoahHeap* heap = ShenandoahHeap::heap();
56 size_t start_idx = heap->heap_region_index_containing(start);
57 #ifdef ASSERT
58 size_t end_idx = heap->heap_region_index_containing(end - 1);
59 assert(start_idx == end_idx, "Expected range to be within same region (" SIZE_FORMAT ", " SIZE_FORMAT ")", start_idx, end_idx);
60 #endif
61 ShenandoahHeapRegion* r = heap->get_region(start_idx);
62 if (!heap->is_bitmap_slice_committed(r)) {
63 return true;
64 }
65 }
66 return _mark_bit_map.is_bitmap_clear_range(start, end);
67 }
68
69 void ShenandoahMarkingContext::initialize_top_at_mark_start(ShenandoahHeapRegion* r) {
70 size_t idx = r->index();
71 HeapWord *bottom = r->bottom();
72
73 _top_at_mark_starts_base[idx] = bottom;
74 _top_bitmaps[idx] = bottom;
75
76 log_debug(gc)("SMC:initialize_top_at_mark_start for Region " SIZE_FORMAT ", TAMS: " PTR_FORMAT ", TopOfBitMap: " PTR_FORMAT,
77 r->index(), p2i(bottom), p2i(r->end()));
78 }
79
80 HeapWord* ShenandoahMarkingContext::top_bitmap(ShenandoahHeapRegion* r) {
81 return _top_bitmaps[r->index()];
82 }
83
84 void ShenandoahMarkingContext::clear_bitmap(ShenandoahHeapRegion* r) {
85 HeapWord* bottom = r->bottom();
86 HeapWord* top_bitmap = _top_bitmaps[r->index()];
87
88 log_debug(gc)("SMC:clear_bitmap for %s Region " SIZE_FORMAT ", top_bitmap: " PTR_FORMAT,
89 r->affiliation_name(), r->index(), p2i(top_bitmap));
90
91 if (top_bitmap > bottom) {
92 _mark_bit_map.clear_range_large(MemRegion(bottom, top_bitmap));
93 _top_bitmaps[r->index()] = bottom;
94 }
95
96 assert(is_bitmap_range_within_region_clear(bottom, r->end()),
97 "Region " SIZE_FORMAT " should have no marks in bitmap", r->index());
98 }
99
100 bool ShenandoahMarkingContext::is_complete() {
101 return _is_complete.is_set();
102 }
103
104 void ShenandoahMarkingContext::mark_complete() {
105 _is_complete.set();
106 }
107
108 void ShenandoahMarkingContext::mark_incomplete() {
109 _is_complete.unset();
110 }