1 /*
2 * Copyright (c) 2005, 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.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/parallel/objectStartArray.hpp"
27 #include "gc/parallel/parMarkBitMap.inline.hpp"
28 #include "gc/parallel/parallelScavengeHeap.hpp"
29 #include "gc/parallel/psCompactionManager.inline.hpp"
30 #include "gc/parallel/psOldGen.hpp"
31 #include "gc/parallel/psParallelCompact.inline.hpp"
32 #include "gc/shared/preservedMarks.inline.hpp"
33 #include "gc/shared/taskqueue.inline.hpp"
34 #include "logging/log.hpp"
35 #include "memory/iterator.inline.hpp"
36 #include "oops/access.inline.hpp"
37 #include "oops/compressedOops.inline.hpp"
38 #include "oops/flatArrayKlass.inline.hpp"
39 #include "oops/instanceKlass.inline.hpp"
40 #include "oops/instanceMirrorKlass.inline.hpp"
41 #include "oops/objArrayKlass.inline.hpp"
42 #include "oops/oop.inline.hpp"
43
44 PSOldGen* ParCompactionManager::_old_gen = nullptr;
45 ParCompactionManager** ParCompactionManager::_manager_array = nullptr;
46
47 ParCompactionManager::OopTaskQueueSet* ParCompactionManager::_oop_task_queues = nullptr;
48 ParCompactionManager::ObjArrayTaskQueueSet* ParCompactionManager::_objarray_task_queues = nullptr;
49 ParCompactionManager::RegionTaskQueueSet* ParCompactionManager::_region_task_queues = nullptr;
50
51 ObjectStartArray* ParCompactionManager::_start_array = nullptr;
52 ParMarkBitMap* ParCompactionManager::_mark_bitmap = nullptr;
53 GrowableArray<size_t >* ParCompactionManager::_shadow_region_array = nullptr;
54 Monitor* ParCompactionManager::_shadow_region_monitor = nullptr;
55
56 PreservedMarksSet* ParCompactionManager::_preserved_marks_set = nullptr;
57
58 ParCompactionManager::ParCompactionManager(PreservedMarks* preserved_marks,
59 ReferenceProcessor* ref_processor)
60 : _mark_and_push_closure(this, ref_processor) {
61
62 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
63
64 _old_gen = heap->old_gen();
65 _start_array = old_gen()->start_array();
66
67 _preserved_marks = preserved_marks;
68 _marking_stats_cache = nullptr;
69 }
70
71 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
72 assert(ParallelScavengeHeap::heap() != nullptr, "Needed for initialization");
73 assert(PSParallelCompact::ref_processor() != nullptr, "precondition");
74 assert(ParallelScavengeHeap::heap()->workers().max_workers() != 0, "Not initialized?");
75
76 _mark_bitmap = mbm;
77
78 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().max_workers();
79
80 assert(_manager_array == nullptr, "Attempt to initialize twice");
81 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads, mtGC);
82
83 _oop_task_queues = new OopTaskQueueSet(parallel_gc_threads);
84 _objarray_task_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
85 _region_task_queues = new RegionTaskQueueSet(parallel_gc_threads);
86
87 _preserved_marks_set = new PreservedMarksSet(true);
88 _preserved_marks_set->init(parallel_gc_threads);
89
90 // Create and register the ParCompactionManager(s) for the worker threads.
91 for(uint i=0; i<parallel_gc_threads; i++) {
92 _manager_array[i] = new ParCompactionManager(_preserved_marks_set->get(i),
93 PSParallelCompact::ref_processor());
94 oop_task_queues()->register_queue(i, _manager_array[i]->oop_stack());
95 _objarray_task_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
96 region_task_queues()->register_queue(i, _manager_array[i]->region_stack());
97 }
98
99 _shadow_region_array = new (mtGC) GrowableArray<size_t >(10, mtGC);
100
101 _shadow_region_monitor = new Monitor(Mutex::nosafepoint, "CompactionManager_lock");
102
103 }
104
105 void ParCompactionManager::flush_all_string_dedup_requests() {
106 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().max_workers();
107 for (uint i=0; i<parallel_gc_threads; i++) {
108 _manager_array[i]->flush_string_dedup_requests();
109 }
110 }
111
112 ParCompactionManager*
113 ParCompactionManager::gc_thread_compaction_manager(uint index) {
114 assert(index < ParallelGCThreads, "index out of range");
115 assert(_manager_array != nullptr, "Sanity");
116 return _manager_array[index];
117 }
118
119 inline void ParCompactionManager::publish_and_drain_oop_tasks() {
120 oop obj;
121 while (oop_stack()->pop_overflow(obj)) {
122 if (!oop_stack()->try_push_to_taskqueue(obj)) {
123 follow_contents(obj);
124 }
125 }
126 while (oop_stack()->pop_local(obj)) {
127 follow_contents(obj);
128 }
129 }
130
131 bool ParCompactionManager::publish_or_pop_objarray_tasks(ObjArrayTask& task) {
132 while (_objarray_stack.pop_overflow(task)) {
133 if (!_objarray_stack.try_push_to_taskqueue(task)) {
134 return true;
135 }
136 }
137 return false;
138 }
139
140 void ParCompactionManager::follow_marking_stacks() {
141 do {
142 // First, try to move tasks from the overflow stack into the shared buffer, so
143 // that other threads can steal. Otherwise process the overflow stack first.
144 publish_and_drain_oop_tasks();
145
146 // Process ObjArrays one at a time to avoid marking stack bloat.
147 ObjArrayTask task;
148 if (publish_or_pop_objarray_tasks(task) ||
149 _objarray_stack.pop_local(task)) {
150 follow_array((objArrayOop)task.obj(), task.index());
151 }
152 } while (!marking_stacks_empty());
153
154 assert(marking_stacks_empty(), "Sanity");
155 }
156
157 void ParCompactionManager::drain_region_stacks() {
158 do {
159 // Drain overflow stack first so other threads can steal.
160 size_t region_index;
161 while (region_stack()->pop_overflow(region_index)) {
162 PSParallelCompact::fill_and_update_region(this, region_index);
163 }
164
165 while (region_stack()->pop_local(region_index)) {
166 PSParallelCompact::fill_and_update_region(this, region_index);
167 }
168 } while (!region_stack()->is_empty());
169 }
170
171 size_t ParCompactionManager::pop_shadow_region_mt_safe(PSParallelCompact::RegionData* region_ptr) {
172 MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
173 while (true) {
174 if (!_shadow_region_array->is_empty()) {
175 return _shadow_region_array->pop();
176 }
177 // Check if the corresponding heap region is available now.
178 // If so, we don't need to get a shadow region anymore, and
179 // we return InvalidShadow to indicate such a case.
180 if (region_ptr->claimed()) {
181 return InvalidShadow;
182 }
183 ml.wait(1);
184 }
185 }
186
187 void ParCompactionManager::push_shadow_region_mt_safe(size_t shadow_region) {
188 MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
189 _shadow_region_array->push(shadow_region);
190 ml.notify();
191 }
192
193 void ParCompactionManager::push_shadow_region(size_t shadow_region) {
194 _shadow_region_array->push(shadow_region);
195 }
196
197 void ParCompactionManager::remove_all_shadow_regions() {
198 _shadow_region_array->clear();
199 }
200
201 #ifdef ASSERT
202 void ParCompactionManager::verify_all_marking_stack_empty() {
203 uint parallel_gc_threads = ParallelGCThreads;
204 for (uint i = 0; i < parallel_gc_threads; i++) {
205 assert(_manager_array[i]->marking_stacks_empty(), "Marking stack should be empty");
206 }
207 }
208
209 void ParCompactionManager::verify_all_region_stack_empty() {
210 uint parallel_gc_threads = ParallelGCThreads;
211 for (uint i = 0; i < parallel_gc_threads; i++) {
212 assert(_manager_array[i]->region_stack()->is_empty(), "Region stack should be empty");
213 }
214 }
215 #endif