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