1 /*
2 * Copyright (c) 2005, 2019, 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 #include "runtime/atomic.hpp"
43
44 PSOldGen* ParCompactionManager::_old_gen = NULL;
45 ParCompactionManager** ParCompactionManager::_manager_array = NULL;
46
47 OopTaskQueueSet* ParCompactionManager::_stack_array = NULL;
48 ParCompactionManager::ObjArrayTaskQueueSet*
49 ParCompactionManager::_objarray_queues = NULL;
50 ObjectStartArray* ParCompactionManager::_start_array = NULL;
51 ParMarkBitMap* ParCompactionManager::_mark_bitmap = NULL;
52 RegionTaskQueueSet* ParCompactionManager::_region_array = NULL;
53 GrowableArray<size_t >* ParCompactionManager::_shadow_region_array = NULL;
54 Monitor* ParCompactionManager::_shadow_region_monitor = NULL;
55
56 ParCompactionManager::ParCompactionManager() :
57 _action(CopyAndUpdate) {
58
59 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
60
61 _old_gen = heap->old_gen();
62 _start_array = old_gen()->start_array();
63
64 marking_stack()->initialize();
65 _objarray_stack.initialize();
66 _region_stack.initialize();
67
68 reset_bitmap_query_cache();
69 }
70
71 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
72 assert(ParallelScavengeHeap::heap() != NULL,
73 "Needed for initialization");
74
75 _mark_bitmap = mbm;
76
77 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().total_workers();
78
79 assert(_manager_array == NULL, "Attempt to initialize twice");
80 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC);
81
82 _stack_array = new OopTaskQueueSet(parallel_gc_threads);
83 guarantee(_stack_array != NULL, "Could not allocate stack_array");
84 _objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
85 guarantee(_objarray_queues != NULL, "Could not allocate objarray_queues");
86 _region_array = new RegionTaskQueueSet(parallel_gc_threads);
87 guarantee(_region_array != NULL, "Could not allocate region_array");
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();
92 guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");
93 stack_array()->register_queue(i, _manager_array[i]->marking_stack());
94 _objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
95 region_array()->register_queue(i, _manager_array[i]->region_stack());
96 }
97
98 // The VMThread gets its own ParCompactionManager, which is not available
99 // for work stealing.
100 _manager_array[parallel_gc_threads] = new ParCompactionManager();
101 guarantee(_manager_array[parallel_gc_threads] != NULL,
102 "Could not create ParCompactionManager");
103 assert(ParallelScavengeHeap::heap()->workers().total_workers() != 0,
104 "Not initialized?");
105
106 _shadow_region_array = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<size_t >(10, true);
107 guarantee(_shadow_region_array != NULL, "Could not allocate shadow_region_array");
108
109 _shadow_region_monitor = new Monitor(Mutex::barrier, "CompactionManager monitor",
110 Mutex::_allow_vm_block_flag, Monitor::_safepoint_check_never);
111 guarantee(_shadow_region_monitor != NULL, "Could not allocate shadow_region_monitor");
112 }
113
114 void ParCompactionManager::reset_all_bitmap_query_caches() {
115 uint parallel_gc_threads = ParallelScavengeHeap::heap()->workers().total_workers();
116 for (uint i=0; i<=parallel_gc_threads; i++) {
117 _manager_array[i]->reset_bitmap_query_cache();
118 }
119 }
120
121 bool ParCompactionManager::should_update() {
122 assert(action() != NotValid, "Action is not set");
123 return (action() == ParCompactionManager::Update) ||
124 (action() == ParCompactionManager::CopyAndUpdate) ||
125 (action() == ParCompactionManager::UpdateAndCopy);
126 }
127
128 bool ParCompactionManager::should_copy() {
129 assert(action() != NotValid, "Action is not set");
130 return (action() == ParCompactionManager::Copy) ||
131 (action() == ParCompactionManager::CopyAndUpdate) ||
132 (action() == ParCompactionManager::UpdateAndCopy);
133 }
134
135 ParCompactionManager*
136 ParCompactionManager::gc_thread_compaction_manager(uint index) {
137 assert(index < ParallelGCThreads, "index out of range");
138 assert(_manager_array != NULL, "Sanity");
139 return _manager_array[index];
140 }
141
142 void ParCompactionManager::follow_marking_stacks() {
143 do {
144 // Drain the overflow stack first, to allow stealing from the marking stack.
145 oop obj;
146 while (marking_stack()->pop_overflow(obj)) {
147 follow_contents(obj);
148 }
149 while (marking_stack()->pop_local(obj)) {
150 follow_contents(obj);
151 }
152
153 // Process ObjArrays one at a time to avoid marking stack bloat.
154 ObjArrayTask task;
155 if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
156 follow_array((objArrayOop)task.obj(), task.index());
157 }
158 } while (!marking_stacks_empty());
159
160 assert(marking_stacks_empty(), "Sanity");
161 }
162
163 void ParCompactionManager::drain_region_stacks() {
164 do {
165 // Drain overflow stack first so other threads can steal.
166 size_t region_index;
167 while (region_stack()->pop_overflow(region_index)) {
168 PSParallelCompact::fill_and_update_region(this, region_index);
169 }
170
171 while (region_stack()->pop_local(region_index)) {
172 PSParallelCompact::fill_and_update_region(this, region_index);
173 }
174 } while (!region_stack()->is_empty());
175 }
176
177 size_t ParCompactionManager::acquire_shadow_region(PSParallelCompact::RegionData* region_ptr) {
178 while (true) {
179 MutexLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
180 if (_shadow_region_array->is_empty()) {
181 // The corresponding heap region may be available now,
182 // so we don't need to acquire a shadow region anymore,
183 // and we return 0 to indicate this case
184 if (region_ptr->claimed()) {
185 return 0;
186 }
187 } else {
188 return _shadow_region_array->pop();
189 }
190 }
191 }
192
193 void ParCompactionManager::release_shadow_region(size_t shadow_region) {
194 MutexLocker ml(_shadow_region_monitor, Mutex::_no_safepoint_check_flag);
195 _shadow_region_array->append(shadow_region);
196 }
197
198 void ParCompactionManager::enqueue_shadow_region(size_t shadow_region) {
199 _shadow_region_array->append(shadow_region);
200 }
201
202 void ParCompactionManager::dequeue_shadow_region() {
203 _shadow_region_array->clear();
204 }