1 /*
2 * Copyright (c) 2017, 2022, 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
25 #include "precompiled.hpp"
26 #include "gc/g1/g1CollectedHeap.inline.hpp"
27 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
28 #include "gc/g1/g1FullCollector.inline.hpp"
29 #include "gc/g1/g1FullGCCompactionPoint.hpp"
30 #include "gc/g1/g1FullGCMarker.hpp"
31 #include "gc/g1/g1FullGCOopClosures.inline.hpp"
32 #include "gc/g1/g1FullGCPrepareTask.inline.hpp"
33 #include "gc/g1/g1HotCardCache.hpp"
34 #include "gc/g1/heapRegion.inline.hpp"
35 #include "gc/shared/gcTraceTime.inline.hpp"
36 #include "gc/shared/referenceProcessor.hpp"
37 #include "logging/log.hpp"
38 #include "memory/iterator.inline.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "utilities/ticks.hpp"
41
42 G1DetermineCompactionQueueClosure::G1DetermineCompactionQueueClosure(G1FullCollector* collector) :
43 _g1h(G1CollectedHeap::heap()),
44 _collector(collector),
45 _cur_worker(0) { }
46
47 bool G1FullGCPrepareTask::G1CalculatePointersClosure::do_heap_region(HeapRegion* hr) {
48 uint region_idx = hr->hrm_index();
49 assert(_collector->is_compaction_target(region_idx), "must be");
50
51 assert(!hr->is_pinned(), "must be");
52 assert(!hr->is_closed_archive(), "must be");
53 assert(!hr->is_open_archive(), "must be");
54
55 prepare_for_compaction(hr);
56
57 return false;
58 }
59
60 G1FullGCPrepareTask::G1FullGCPrepareTask(G1FullCollector* collector) :
61 G1FullGCTask("G1 Prepare Compact Task", collector),
62 _has_free_compaction_targets(false),
63 _hrclaimer(collector->workers()) {
64 }
65
66 void G1FullGCPrepareTask::set_has_free_compaction_targets() {
67 if (!_has_free_compaction_targets) {
68 _has_free_compaction_targets = true;
69 }
70 }
71
72 bool G1FullGCPrepareTask::has_free_compaction_targets() {
73 return _has_free_compaction_targets;
74 }
75
76 void G1FullGCPrepareTask::work(uint worker_id) {
77 Ticks start = Ticks::now();
78 // Calculate the target locations for the objects in the non-free regions of
79 // the compaction queues provided by the associate compaction point.
80 {
81 G1FullGCCompactionPoint* compaction_point = collector()->compaction_point(worker_id);
82 G1CalculatePointersClosure closure(collector(), compaction_point);
83
84 for (GrowableArrayIterator<HeapRegion*> it = compaction_point->regions()->begin();
85 it != compaction_point->regions()->end();
86 ++it) {
87 closure.do_heap_region(*it);
88 }
89 compaction_point->update();
90 // Determine if there are any unused compaction targets. This is only the case if
91 // there are
92 // - any regions in queue, so no free ones either.
93 // - and the current region is not the last one in the list.
94 if (compaction_point->has_regions() &&
95 compaction_point->current_region() != compaction_point->regions()->last()) {
96 set_has_free_compaction_targets();
97 }
98 }
99
100 // Clear region metadata that is invalid after GC for all regions.
101 {
102 G1ResetMetadataClosure closure(collector());
103 G1CollectedHeap::heap()->heap_region_par_iterate_from_start(&closure, &_hrclaimer);
104 }
105 log_task("Prepare compaction task", worker_id, start);
106 }
107
108 G1FullGCPrepareTask::G1CalculatePointersClosure::G1CalculatePointersClosure(G1FullCollector* collector,
109 G1FullGCCompactionPoint* cp) :
110 _g1h(G1CollectedHeap::heap()),
111 _collector(collector),
112 _bitmap(collector->mark_bitmap()),
113 _cp(cp) { }
114
115 G1FullGCPrepareTask::G1ResetMetadataClosure::G1ResetMetadataClosure(G1FullCollector* collector) :
116 _g1h(G1CollectedHeap::heap()),
117 _collector(collector) { }
118
119 void G1FullGCPrepareTask::G1ResetMetadataClosure::reset_region_metadata(HeapRegion* hr) {
120 hr->rem_set()->clear();
121 hr->clear_cardtable();
122
123 G1HotCardCache* hcc = _g1h->hot_card_cache();
124 if (hcc->use_cache()) {
125 hcc->reset_card_counts(hr);
126 }
127 }
128
129 bool G1FullGCPrepareTask::G1ResetMetadataClosure::do_heap_region(HeapRegion* hr) {
130 uint const region_idx = hr->hrm_index();
131 if (!_collector->is_compaction_target(region_idx)) {
132 assert(!hr->is_free(), "all free regions should be compaction targets");
133 assert(_collector->is_skip_compacting(region_idx) || hr->is_closed_archive(), "must be");
134 if (hr->is_young()) {
135 // G1 updates the BOT for old region contents incrementally, but young regions
136 // lack BOT information for performance reasons.
137 // Recreate BOT information of high live ratio young regions here to keep expected
138 // performance during scanning their card tables in the collection pauses later.
139 hr->update_bot();
140 }
141 }
142
143 // Reset data structures not valid after Full GC.
144 reset_region_metadata(hr);
145
146 return false;
147 }
148
149 G1FullGCPrepareTask::G1PrepareCompactLiveClosure::G1PrepareCompactLiveClosure(G1FullGCCompactionPoint* cp) :
150 _cp(cp) { }
151
152 size_t G1FullGCPrepareTask::G1PrepareCompactLiveClosure::apply(oop object) {
153 size_t size = object->size();
154 _cp->forward(object, size);
155 return size;
156 }
157
158 void G1FullGCPrepareTask::G1CalculatePointersClosure::prepare_for_compaction(HeapRegion* hr) {
159 if (!_collector->is_free(hr->hrm_index())) {
160 G1PrepareCompactLiveClosure prepare_compact(_cp);
161 hr->apply_to_marked_objects(_bitmap, &prepare_compact);
162 }
163 }