1 /*
2 * Copyright (c) 2005, 2020, 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 "classfile/systemDictionary.hpp"
27 #include "gc/parallel/objectStartArray.hpp"
28 #include "gc/parallel/parMarkBitMap.inline.hpp"
29 #include "gc/parallel/parallelScavengeHeap.hpp"
30 #include "gc/parallel/psCompactionManager.inline.hpp"
31 #include "gc/parallel/psOldGen.hpp"
32 #include "gc/parallel/psParallelCompact.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 = NULL;
44 ParCompactionManager** ParCompactionManager::_manager_array = NULL;
45
46 ParCompactionManager::OopTaskQueueSet* ParCompactionManager::_oop_task_queues = NULL;
47 ParCompactionManager::ObjArrayTaskQueueSet* ParCompactionManager::_objarray_task_queues = NULL;
48 ParCompactionManager::RegionTaskQueueSet* ParCompactionManager::_region_task_queues = NULL;
49
50 ObjectStartArray* ParCompactionManager::_start_array = NULL;
51 ParMarkBitMap* ParCompactionManager::_mark_bitmap = NULL;
52 GrowableArray<size_t >* ParCompactionManager::_shadow_region_array = NULL;
53 Monitor* ParCompactionManager::_shadow_region_monitor = NULL;
54
55 ParCompactionManager::ParCompactionManager() {
56
57 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
58
59 _old_gen = heap->old_gen();
60 _start_array = old_gen()->start_array();
61
62 marking_stack()->initialize();
63 _objarray_stack.initialize();
64 _region_stack.initialize();
65
66 reset_bitmap_query_cache();
67 }
68
69 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
70 assert(ParallelScavengeHeap::heap() != NULL,
71 "Needed for initialization");
72
73 _mark_bitmap = mbm;
74
75 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().total_workers();
76
77 assert(_manager_array == NULL, "Attempt to initialize twice");
78 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC);
79
80 _oop_task_queues = new OopTaskQueueSet(parallel_gc_threads);
81 _objarray_task_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
82 _region_task_queues = new RegionTaskQueueSet(parallel_gc_threads);
83
84 // Create and register the ParCompactionManager(s) for the worker threads.
85 for(uint i=0; i<parallel_gc_threads; i++) {
86 _manager_array[i] = new ParCompactionManager();
87 oop_task_queues()->register_queue(i, _manager_array[i]->marking_stack());
88 _objarray_task_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
89 region_task_queues()->register_queue(i, _manager_array[i]->region_stack());
90 }
91
92 // The VMThread gets its own ParCompactionManager, which is not available
93 // for work stealing.
94 _manager_array[parallel_gc_threads] = new ParCompactionManager();
95 assert(ParallelScavengeHeap::heap()->workers().total_workers() != 0,
96 "Not initialized?");
97
98 _shadow_region_array = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<size_t >(10, true);
99
100 _shadow_region_monitor = new Monitor(Mutex::barrier, "CompactionManager monitor",
101 Mutex::_allow_vm_block_flag, Monitor::_safepoint_check_never);
102 }
103
104 void ParCompactionManager::reset_all_bitmap_query_caches() {
105 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().total_workers();
106 for (uint i=0; i<=parallel_gc_threads; i++) {
107 _manager_array[i]->reset_bitmap_query_cache();
108 }
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 != NULL, "Sanity");
116 return _manager_array[index];
117 }
118
119 void ParCompactionManager::follow_marking_stacks() {
120 do {
121 // Drain the overflow stack first, to allow stealing from the marking stack.
122 oop obj;
123 while (marking_stack()->pop_overflow(obj)) {
124 follow_contents(obj);
125 }
126 while (marking_stack()->pop_local(obj)) {
127 follow_contents(obj);
128 }
129
130 // Process ObjArrays one at a time to avoid marking stack bloat.
131 ObjArrayTask task;
132 if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
133 follow_array((objArrayOop)task.obj(), task.index());
134 }
135 } while (!marking_stacks_empty());
136
137 assert(marking_stacks_empty(), "Sanity");
138 }
139
140 void ParCompactionManager::drain_region_stacks() {
141 do {
142 // Drain overflow stack first so other threads can steal.
143 size_t region_index;
144 while (region_stack()->pop_overflow(region_index)) {
145 PSParallelCompact::fill_and_update_region(this, region_index);
146 }
147
148 while (region_stack()->pop_local(region_index)) {
149 PSParallelCompact::fill_and_update_region(this, region_index);
150 }
151 } while (!region_stack()->is_empty());
152 }
153
154 size_t ParCompactionManager::pop_shadow_region_mt_safe(PSParallelCompact::RegionData* region_ptr) {
155 MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
156 while (true) {
157 if (!_shadow_region_array->is_empty()) {
158 return _shadow_region_array->pop();
159 }
160 // Check if the corresponding heap region is available now.
161 // If so, we don't need to get a shadow region anymore, and
162 // we return InvalidShadow to indicate such a case.
163 if (region_ptr->claimed()) {
164 return InvalidShadow;
165 }
166 ml.wait(1);
167 }
168 }
169
170 void ParCompactionManager::push_shadow_region_mt_safe(size_t shadow_region) {
171 MonitorLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
172 _shadow_region_array->push(shadow_region);
173 ml.notify();
174 }
175
176 void ParCompactionManager::push_shadow_region(size_t shadow_region) {
177 _shadow_region_array->push(shadow_region);
178 }
179
180 void ParCompactionManager::remove_all_shadow_regions() {
181 _shadow_region_array->clear();
182 }