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/g1HeapRegion.inline.hpp"
35 #include "gc/shared/slidingForwarding.inline.hpp"
36
37 void G1DetermineCompactionQueueClosure::free_empty_humongous_region(G1HeapRegion* 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(G1HeapRegion* 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() || hr->has_pinned_objects()) {
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(G1HeapRegion* 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 static bool has_pinned_objects(G1HeapRegion* hr) {
78 return hr->has_pinned_objects() ||
79 (hr->is_humongous() && hr->humongous_start_region()->has_pinned_objects());
80 }
81
82 inline bool G1DetermineCompactionQueueClosure::do_heap_region(G1HeapRegion* hr) {
83 if (should_compact(hr)) {
84 assert(!hr->is_humongous(), "moving humongous objects not supported.");
85 add_to_compaction_queue(hr);
86 return false;
87 }
88
89 assert(hr->containing_set() == nullptr, "already cleared by PrepareRegionsClosure");
90 if (has_pinned_objects(hr)) {
91 // First check regions with pinned objects: they need to be skipped regardless
92 // of region type and never be considered for reclamation.
93 assert(_collector->is_skip_compacting(hr->hrm_index()), "pinned region %u must be skip_compacting", hr->hrm_index());
94 log_trace(gc, phases)("Phase 2: skip compaction region index: %u (%s), has pinned objects",
95 hr->hrm_index(), hr->get_short_type_str());
96 } else if (hr->is_humongous()) {
97 oop obj = cast_to_oop(hr->humongous_start_region()->bottom());
98 bool is_empty = !_collector->mark_bitmap()->is_marked(obj);
99 if (is_empty) {
100 free_empty_humongous_region(hr);
101 } else {
102 _collector->set_has_humongous();
103 }
104 } else {
105 assert(MarkSweepDeadRatio > 0,
106 "only skip compaction for other regions when MarkSweepDeadRatio > 0");
107
108 // Too many live objects in the region; skip compacting it.
109 _collector->update_from_compacting_to_skip_compacting(hr->hrm_index());
110 log_trace(gc, phases)("Phase 2: skip compaction region index: %u, live words: " SIZE_FORMAT,
111 hr->hrm_index(), _collector->live_words(hr->hrm_index()));
112 }
113
114 return false;
115 }
116
117 inline size_t G1SerialRePrepareClosure::apply(oop obj) {
118 if (SlidingForwarding::is_forwarded(obj)) {
119 // We skip objects compiled into the first region or
120 // into regions not part of the serial compaction point.
121 if (cast_from_oop<HeapWord*>(SlidingForwarding::forwardee(obj)) < _dense_prefix_top) {
122 return obj->size();
123 }
124 }
125
126 // Get size and forward.
127 size_t size = obj->size();
128 _cp->forward(obj, size);
129
130 return size;
131 }
132
133 #endif // SHARE_GC_G1_G1FULLGCPREPARETASK_INLINE_HPP