1 /*
2 * Copyright (c) 2022, 2023, 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.
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23 */
24
25 #ifndef SHARE_GC_G1_G1FULLGCPREPARETASK_INLINE_HPP
26 #define SHARE_GC_G1_G1FULLGCPREPARETASK_INLINE_HPP
27
28 #include "gc/g1/g1FullGCPrepareTask.hpp"
29
30 #include "gc/g1/g1CollectedHeap.inline.hpp"
31 #include "gc/g1/g1FullCollector.hpp"
32 #include "gc/g1/g1FullGCCompactionPoint.hpp"
33 #include "gc/g1/g1FullGCScope.hpp"
34 #include "gc/g1/heapRegion.inline.hpp"
35 #include "gc/shared/slidingForwarding.inline.hpp"
36
37 void G1DetermineCompactionQueueClosure::free_empty_humongous_region(HeapRegion* hr) {
38 _g1h->free_humongous_region(hr, nullptr);
39 _collector->set_free(hr->hrm_index());
40 add_to_compaction_queue(hr);
41 }
42
43 inline bool G1DetermineCompactionQueueClosure::should_compact(HeapRegion* hr) const {
44 // There is no need to iterate and forward objects in non-movable regions ie.
45 // prepare them for compaction.
46 if (hr->is_humongous()) {
47 return false;
48 }
49 size_t live_words = _collector->live_words(hr->hrm_index());
50 size_t live_words_threshold = _collector->scope()->region_compaction_threshold();
51 // High live ratio region will not be compacted.
52 return live_words <= live_words_threshold;
53 }
54
55 inline uint G1DetermineCompactionQueueClosure::next_worker() {
56 uint result = _cur_worker;
57 _cur_worker = (_cur_worker + 1) % _collector->workers();
58 return result;
59 }
60
61 inline G1FullGCCompactionPoint* G1DetermineCompactionQueueClosure::next_compaction_point() {
62 return _collector->compaction_point(next_worker());
63 }
64
65 inline void G1DetermineCompactionQueueClosure::add_to_compaction_queue(HeapRegion* hr) {
66 _collector->set_compaction_top(hr, hr->bottom());
67 _collector->set_has_compaction_targets();
68
69 G1FullGCCompactionPoint* cp = next_compaction_point();
70 if (!cp->is_initialized()) {
71 cp->initialize(hr);
72 }
73 // Add region to the compaction queue.
74 cp->add(hr);
75 }
76
77 inline bool G1DetermineCompactionQueueClosure::do_heap_region(HeapRegion* hr) {
78 if (should_compact(hr)) {
79 assert(!hr->is_humongous(), "moving humongous objects not supported.");
80 add_to_compaction_queue(hr);
81 } else {
82 assert(hr->containing_set() == nullptr, "already cleared by PrepareRegionsClosure");
83 if (hr->is_humongous()) {
84 oop obj = cast_to_oop(hr->humongous_start_region()->bottom());
85 bool is_empty = !_collector->mark_bitmap()->is_marked(obj);
86 if (is_empty) {
87 free_empty_humongous_region(hr);
88 } else {
89 _collector->set_has_humongous();
90 }
91 } else {
92 assert(MarkSweepDeadRatio > 0,
93 "only skip compaction for other regions when MarkSweepDeadRatio > 0");
94
95 // Too many live objects in the region; skip compacting it.
96 _collector->update_from_compacting_to_skip_compacting(hr->hrm_index());
97 log_trace(gc, phases)("Phase 2: skip compaction region index: %u, live words: " SIZE_FORMAT,
98 hr->hrm_index(), _collector->live_words(hr->hrm_index()));
99 }
100 }
101
102 return false;
103 }
104
105 template <bool ALT_FWD>
106 inline size_t G1SerialRePrepareClosure<ALT_FWD>::apply(oop obj) {
107 if (SlidingForwarding::is_forwarded(obj)) {
108 // We skip objects compiled into the first region or
109 // into regions not part of the serial compaction point.
110 if (cast_from_oop<HeapWord*>(SlidingForwarding::forwardee<ALT_FWD>(obj)) < _dense_prefix_top) {
111 return obj->size();
112 }
113 }
114
115 // Get size and forward.
116 size_t size = obj->size();
117 _cp->forward<ALT_FWD>(obj, size);
118
119 return size;
120 }
121
122 #endif // SHARE_GC_G1_G1FULLGCPREPARETASK_INLINE_HPP