1 /*
2 * Copyright (c) 2005, 2021, 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/taskqueue.inline.hpp"
33 #include "logging/log.hpp"
34 #include "memory/iterator.inline.hpp"
35 #include "oops/access.inline.hpp"
36 #include "oops/compressedOops.inline.hpp"
37 #include "oops/instanceKlass.inline.hpp"
38 #include "oops/instanceMirrorKlass.inline.hpp"
39 #include "oops/objArrayKlass.inline.hpp"
40 #include "oops/oop.inline.hpp"
41
42 PSOldGen* ParCompactionManager::_old_gen = NULL;
43 ParCompactionManager** ParCompactionManager::_manager_array = NULL;
44
45 ParCompactionManager::OopTaskQueueSet* ParCompactionManager::_oop_task_queues = NULL;
46 ParCompactionManager::ObjArrayTaskQueueSet* ParCompactionManager::_objarray_task_queues = NULL;
47 ParCompactionManager::RegionTaskQueueSet* ParCompactionManager::_region_task_queues = NULL;
48
49 ObjectStartArray* ParCompactionManager::_start_array = NULL;
50 ParMarkBitMap* ParCompactionManager::_mark_bitmap = NULL;
51 GrowableArray<size_t >* ParCompactionManager::_shadow_region_array = NULL;
52 Monitor* ParCompactionManager::_shadow_region_monitor = NULL;
53
54 ParCompactionManager::ParCompactionManager() {
55
56 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
57
58 _old_gen = heap->old_gen();
59 _start_array = old_gen()->start_array();
60
61 reset_bitmap_query_cache();
62 }
63
64 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
65 assert(ParallelScavengeHeap::heap() != NULL,
66 "Needed for initialization");
67
68 _mark_bitmap = mbm;
69
70 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().max_workers();
71
72 assert(_manager_array == NULL, "Attempt to initialize twice");
73 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads, mtGC);
74
75 _oop_task_queues = new OopTaskQueueSet(parallel_gc_threads);
76 _objarray_task_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
77 _region_task_queues = new RegionTaskQueueSet(parallel_gc_threads);
78
79 // Create and register the ParCompactionManager(s) for the worker threads.
80 for(uint i=0; i<parallel_gc_threads; i++) {
81 _manager_array[i] = new ParCompactionManager();
82 oop_task_queues()->register_queue(i, _manager_array[i]->marking_stack());
83 _objarray_task_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
84 region_task_queues()->register_queue(i, _manager_array[i]->region_stack());
85 }
86
87 assert(ParallelScavengeHeap::heap()->workers().max_workers() != 0,
88 "Not initialized?");
89
90 _shadow_region_array = new (ResourceObj::C_HEAP, mtGC) GrowableArray<size_t >(10, mtGC);
91
92 _shadow_region_monitor = new Monitor(Mutex::nosafepoint, "CompactionManager_lock");
93 }
94
95 void ParCompactionManager::reset_all_bitmap_query_caches() {
96 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().max_workers();
97 for (uint i=0; i<parallel_gc_threads; i++) {
98 _manager_array[i]->reset_bitmap_query_cache();
99 }
100 }
101
102 void ParCompactionManager::flush_all_string_dedup_requests() {
103 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().max_workers();
104 for (uint i=0; i<parallel_gc_threads; i++) {
105 _manager_array[i]->flush_string_dedup_requests();
106 }
107 }
108
109 ParCompactionManager*
110 ParCompactionManager::gc_thread_compaction_manager(uint index) {
111 assert(index < ParallelGCThreads, "index out of range");
112 assert(_manager_array != NULL, "Sanity");
113 return _manager_array[index];
114 }
115
116 inline void ParCompactionManager::publish_and_drain_oop_tasks() {
117 oop obj;
118 while (marking_stack()->pop_overflow(obj)) {
119 if (!marking_stack()->try_push_to_taskqueue(obj)) {
120 follow_contents(obj);
121 }
122 }
123 while (marking_stack()->pop_local(obj)) {
124 follow_contents(obj);
125 }
126 }
127
128 bool ParCompactionManager::publish_or_pop_objarray_tasks(ObjArrayTask& task) {
129 while (_objarray_stack.pop_overflow(task)) {
130 if (!_objarray_stack.try_push_to_taskqueue(task)) {
131 return true;
132 }
133 }
134 return false;
135 }
136
137 void ParCompactionManager::follow_marking_stacks() {
138 do {
139 // First, try to move tasks from the overflow stack into the shared buffer, so
140 // that other threads can steal. Otherwise process the overflow stack first.
141 publish_and_drain_oop_tasks();
142
143 // Process ObjArrays one at a time to avoid marking stack bloat.
144 ObjArrayTask task;
145 if (publish_or_pop_objarray_tasks(task) ||
146 _objarray_stack.pop_local(task)) {
147 follow_array((objArrayOop)task.obj(), task.index());
148 }
149 } while (!marking_stacks_empty());
150
151 assert(marking_stacks_empty(), "Sanity");
152 }
153
154 void ParCompactionManager::drain_region_stacks() {
155 do {
156 // Drain overflow stack first so other threads can steal.
157 size_t region_index;
158 while (region_stack()->pop_overflow(region_index)) {
159 PSParallelCompact::fill_and_update_region(this, region_index);
160 }
161
162 while (region_stack()->pop_local(region_index)) {
163 PSParallelCompact::fill_and_update_region(this, region_index);
164 }
165 } while (!region_stack()->is_empty());
166 }
167
168 size_t ParCompactionManager::pop_shadow_region_mt_safe(PSParallelCompact::RegionData* region_ptr) {
169 MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
170 while (true) {
171 if (!_shadow_region_array->is_empty()) {
172 return _shadow_region_array->pop();
173 }
174 // Check if the corresponding heap region is available now.
175 // If so, we don't need to get a shadow region anymore, and
176 // we return InvalidShadow to indicate such a case.
177 if (region_ptr->claimed()) {
178 return InvalidShadow;
179 }
180 ml.wait(1);
181 }
182 }
183
184 void ParCompactionManager::push_shadow_region_mt_safe(size_t shadow_region) {
185 MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
186 _shadow_region_array->push(shadow_region);
187 ml.notify();
188 }
189
190 void ParCompactionManager::push_shadow_region(size_t shadow_region) {
191 _shadow_region_array->push(shadow_region);
192 }
193
194 void ParCompactionManager::remove_all_shadow_regions() {
195 _shadow_region_array->clear();
196 }
197
198 #ifdef ASSERT
199 void ParCompactionManager::verify_all_marking_stack_empty() {
200 uint parallel_gc_threads = ParallelGCThreads;
201 for (uint i = 0; i < parallel_gc_threads; i++) {
202 assert(_manager_array[i]->marking_stacks_empty(), "Marking stack should be empty");
203 }
204 }
205
206 void ParCompactionManager::verify_all_region_stack_empty() {
207 uint parallel_gc_threads = ParallelGCThreads;
208 for (uint i = 0; i < parallel_gc_threads; i++) {
209 assert(_manager_array[i]->region_stack()->is_empty(), "Region stack should be empty");
210 }
211 }
212 #endif