1 /*
2 * Copyright (c) 2017, 2026, 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 "classfile/classLoaderData.hpp"
26 #include "classfile/classLoaderDataGraph.hpp"
27 #include "gc/g1/g1FullGCMarker.inline.hpp"
28 #include "gc/shared/partialArraySplitter.inline.hpp"
29 #include "gc/shared/partialArrayState.hpp"
30 #include "gc/shared/referenceProcessor.hpp"
31 #include "gc/shared/taskTerminator.hpp"
32 #include "gc/shared/verifyOption.hpp"
33 #include "memory/iterator.inline.hpp"
34
35 G1FullGCMarker::G1FullGCMarker(G1FullCollector* collector,
36 uint worker_id,
37 G1RegionMarkStats* mark_stats) :
38 _collector(collector),
39 _worker_id(worker_id),
40 _bitmap(collector->mark_bitmap()),
41 _task_queue(),
42 _partial_array_splitter(collector->partial_array_state_manager(), collector->workers()),
43 _mark_closure(worker_id, this, ClassLoaderData::_claim_stw_fullgc_mark, G1CollectedHeap::heap()->ref_processor_stw()),
44 _stack_closure(this),
45 _cld_closure(mark_closure(), ClassLoaderData::_claim_stw_fullgc_mark),
46 _mark_stats_cache(mark_stats, G1RegionMarkStatsCache::RegionMarkStatsCacheSize) {
47 ClassLoaderDataGraph::verify_claimed_marks_cleared(ClassLoaderData::_claim_stw_fullgc_mark);
48 _mark_stats_cache.reset();
49 }
50
51 G1FullGCMarker::~G1FullGCMarker() {
52 assert(is_task_queue_empty(), "Must be empty at this point");
53 }
54
55 void G1FullGCMarker::process_partial_array(PartialArrayState* state, bool stolen) {
56 // Access state before release by claim().
57 objArrayOop obj_array = objArrayOop(state->source());
58 PartialArraySplitter::Claim claim =
59 _partial_array_splitter.claim(state, task_queue(), stolen);
60 process_array_chunk(obj_array, claim._start, claim._end);
61 }
62
63 static uintx calc_array_stride(uint array_len, uint num_threads) {
64 precond(num_threads > 0);
65
66 const size_t stride = (array_len + num_threads - 1) / num_threads;
67 return clamp(stride, ArrayMarkingMinStride, ObjArrayMarkingStride);
68 }
69
70 void G1FullGCMarker::start_partial_array_processing(objArrayOop obj) {
71 precond(obj->is_array_with_oops());
72 mark_closure()->do_klass(obj->klass());
73
74 // Don't push empty arrays to avoid unnecessary work.
75 const int array_length = obj->length();
76
77 if (array_length == 0) {
78 return;
79 }
80
81 const uintx stride = calc_array_stride(array_length, _collector->workers());
82 const size_t initial_chunk_size = _partial_array_splitter.start(task_queue(), obj, nullptr, array_length, stride);
83
84 process_array_chunk(obj, 0, initial_chunk_size);
85 }
86
87 void G1FullGCMarker::complete_marking(G1ScannerTasksQueueSet* task_queues,
88 TaskTerminator* terminator) {
89 do {
90 process_marking_stacks();
91 ScannerTask stolen_task;
92 if (task_queues->steal(_worker_id, stolen_task)) {
93 dispatch_task(stolen_task, true);
94 }
95 } while (!is_task_queue_empty() || !terminator->offer_termination());
96 }
97
98 void G1FullGCMarker::flush_mark_stats_cache() {
99 _mark_stats_cache.evict_all();
100 }