1 /*
2 * Copyright (c) 2018, 2021, Red Hat, Inc. 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
25 #include "precompiled.hpp"
26 #include "gc/shared/markBitMap.inline.hpp"
27 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
28 #include "gc/shenandoah/shenandoahHeapRegion.inline.hpp"
29 #include "gc/shenandoah/shenandoahMarkingContext.hpp"
30 #include "gc/shenandoah/shenandoahTaskqueue.inline.hpp"
31 #include "utilities/stack.inline.hpp"
32
33 ShenandoahMarkingContext::ShenandoahMarkingContext(MemRegion heap_region, MemRegion bitmap_region, size_t num_regions, uint max_queues) :
34 _mark_bit_map(heap_region, bitmap_region),
35 _top_bitmaps(NEW_C_HEAP_ARRAY(HeapWord*, num_regions, mtGC)),
36 _top_at_mark_starts_base(NEW_C_HEAP_ARRAY(HeapWord*, num_regions, mtGC)),
37 _top_at_mark_starts(_top_at_mark_starts_base -
38 ((uintx) heap_region.start() >> ShenandoahHeapRegion::region_size_bytes_shift())),
39 _task_queues(new ShenandoahObjToScanQueueSet(max_queues)) {
40 assert(max_queues > 0, "At least one queue");
41 for (uint i = 0; i < max_queues; ++i) {
42 ShenandoahObjToScanQueue* task_queue = new ShenandoahObjToScanQueue();
43 _task_queues->register_queue(i, task_queue);
44 }
45 }
46
47 ShenandoahMarkingContext::~ShenandoahMarkingContext() {
48 for (uint i = 0; i < _task_queues->size(); ++i) {
49 ShenandoahObjToScanQueue* q = _task_queues->queue(i);
50 delete q;
51 }
52 delete _task_queues;
53 }
54
55 bool ShenandoahMarkingContext::is_bitmap_clear() const {
56 ShenandoahHeap* heap = ShenandoahHeap::heap();
57 size_t num_regions = heap->num_regions();
58 for (size_t idx = 0; idx < num_regions; idx++) {
59 ShenandoahHeapRegion* r = heap->get_region(idx);
60 if (heap->is_bitmap_slice_committed(r) && !is_bitmap_clear_range(r->bottom(), r->end())) {
61 return false;
62 }
63 }
64 return true;
65 }
66
67 bool ShenandoahMarkingContext::is_bitmap_clear_range(HeapWord* start, HeapWord* end) const {
68 return _mark_bit_map.get_next_marked_addr(start, end) == end;
69 }
70
71 size_t ShenandoahMarkingContext::count_marked(MemRegion mr) const {
72 return _mark_bit_map.count_marked(mr);
73 }
74
75 void ShenandoahMarkingContext::initialize_top_at_mark_start(ShenandoahHeapRegion* r) {
76 size_t idx = r->index();
77 HeapWord *bottom = r->bottom();
78 _top_at_mark_starts_base[idx] = bottom;
79 _top_bitmaps[idx] = bottom;
80 }
81
82 void ShenandoahMarkingContext::clear_bitmap(ShenandoahHeapRegion* r) {
83 HeapWord* bottom = r->bottom();
84 HeapWord* top_bitmap = _top_bitmaps[r->index()];
85 if (top_bitmap > bottom) {
86 _mark_bit_map.clear_range_large(MemRegion(bottom, top_bitmap));
87 _top_bitmaps[r->index()] = bottom;
88 }
89 assert(is_bitmap_clear_range(bottom, r->end()),
90 "Region " SIZE_FORMAT " should have no marks in bitmap", r->index());
91 }
92
93 bool ShenandoahMarkingContext::is_complete() {
94 return _is_complete.is_set();
95 }
96
97 void ShenandoahMarkingContext::mark_complete() {
98 _is_complete.set();
99 }
100
101 void ShenandoahMarkingContext::mark_incomplete() {
102 _is_complete.unset();
103 }