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().total_workers();
71
72 assert(_manager_array == NULL, "Attempt to initialize twice");
73 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, 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 // The VMThread gets its own ParCompactionManager, which is not available
88 // for work stealing.
89 _manager_array[parallel_gc_threads] = new ParCompactionManager();
90 assert(ParallelScavengeHeap::heap()->workers().total_workers() != 0,
91 "Not initialized?");
92
93 _shadow_region_array = new (ResourceObj::C_HEAP, mtGC) GrowableArray<size_t >(10, mtGC);
94
95 _shadow_region_monitor = new Monitor(Mutex::nosafepoint, "CompactionManager_lock",
96 Monitor::_safepoint_check_never);
97 }
98
99 void ParCompactionManager::reset_all_bitmap_query_caches() {
100 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().total_workers();
101 for (uint i=0; i<=parallel_gc_threads; i++) {
102 _manager_array[i]->reset_bitmap_query_cache();
103 }
104 }
105
106 void ParCompactionManager::flush_all_string_dedup_requests() {
107 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().total_workers();
108 for (uint i=0; i<=parallel_gc_threads; i++) {
109 _manager_array[i]->flush_string_dedup_requests();
110 }
111 }
112
113 ParCompactionManager*
114 ParCompactionManager::gc_thread_compaction_manager(uint index) {
115 assert(index < ParallelGCThreads, "index out of range");
116 assert(_manager_array != NULL, "Sanity");
117 return _manager_array[index];
118 }
119
120 void ParCompactionManager::follow_marking_stacks() {
121 do {
122 // Drain the overflow stack first, to allow stealing from the marking stack.
123 oop obj;
124 while (marking_stack()->pop_overflow(obj)) {
125 follow_contents(obj);
126 }
127 while (marking_stack()->pop_local(obj)) {
128 follow_contents(obj);
129 }
130
131 // Process ObjArrays one at a time to avoid marking stack bloat.
132 ObjArrayTask task;
133 if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
134 follow_array((objArrayOop)task.obj(), task.index());
135 }
136 } while (!marking_stacks_empty());
137
138 assert(marking_stacks_empty(), "Sanity");
139 }
140
141 void ParCompactionManager::drain_region_stacks() {
142 do {
143 // Drain overflow stack first so other threads can steal.
144 size_t region_index;
145 while (region_stack()->pop_overflow(region_index)) {
146 PSParallelCompact::fill_and_update_region(this, region_index);
147 }
148
149 while (region_stack()->pop_local(region_index)) {
150 PSParallelCompact::fill_and_update_region(this, region_index);
151 }
152 } while (!region_stack()->is_empty());
153 }
154
155 size_t ParCompactionManager::pop_shadow_region_mt_safe(PSParallelCompact::RegionData* region_ptr) {
156 MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
157 while (true) {
158 if (!_shadow_region_array->is_empty()) {
159 return _shadow_region_array->pop();
160 }
161 // Check if the corresponding heap region is available now.
162 // If so, we don't need to get a shadow region anymore, and
163 // we return InvalidShadow to indicate such a case.
164 if (region_ptr->claimed()) {
165 return InvalidShadow;
166 }
167 ml.wait(1);
168 }
169 }
170
171 void ParCompactionManager::push_shadow_region_mt_safe(size_t shadow_region) {
172 MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
173 _shadow_region_array->push(shadow_region);
174 ml.notify();
175 }
176
177 void ParCompactionManager::push_shadow_region(size_t shadow_region) {
178 _shadow_region_array->push(shadow_region);
179 }
180
181 void ParCompactionManager::remove_all_shadow_regions() {
182 _shadow_region_array->clear();
183 }
184
185 #ifdef ASSERT
186 void ParCompactionManager::verify_all_marking_stack_empty() {
187 uint parallel_gc_threads = ParallelGCThreads;
188 for (uint i = 0; i <= parallel_gc_threads; i++) {
189 assert(_manager_array[i]->marking_stacks_empty(), "Marking stack should be empty");
190 }
191 }
192
193 void ParCompactionManager::verify_all_region_stack_empty() {
194 uint parallel_gc_threads = ParallelGCThreads;
195 for (uint i = 0; i <= parallel_gc_threads; i++) {
196 assert(_manager_array[i]->region_stack()->is_empty(), "Region stack should be empty");
197 }
198 }
199 #endif