1 /*
2 * Copyright (c) 2005, 2018, 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/gcTaskManager.hpp"
28 #include "gc/parallel/objectStartArray.hpp"
29 #include "gc/parallel/parMarkBitMap.inline.hpp"
30 #include "gc/parallel/parallelScavengeHeap.hpp"
31 #include "gc/parallel/psCompactionManager.inline.hpp"
32 #include "gc/parallel/psOldGen.hpp"
33 #include "gc/parallel/psParallelCompact.inline.hpp"
34 #include "gc/shared/taskqueue.inline.hpp"
35 #include "logging/log.hpp"
36 #include "memory/iterator.inline.hpp"
37 #include "oops/access.inline.hpp"
38 #include "oops/compressedOops.inline.hpp"
39 #include "oops/instanceKlass.inline.hpp"
40 #include "oops/instanceMirrorKlass.inline.hpp"
41 #include "oops/objArrayKlass.inline.hpp"
42 #include "oops/oop.inline.hpp"
43 #include "runtime/atomic.hpp"
44
45 PSOldGen* ParCompactionManager::_old_gen = NULL;
46 ParCompactionManager** ParCompactionManager::_manager_array = NULL;
47
48 OopTaskQueueSet* ParCompactionManager::_stack_array = NULL;
49 ParCompactionManager::ObjArrayTaskQueueSet*
50 ParCompactionManager::_objarray_queues = NULL;
51 ObjectStartArray* ParCompactionManager::_start_array = NULL;
52 ParMarkBitMap* ParCompactionManager::_mark_bitmap = NULL;
53 RegionTaskQueueSet* ParCompactionManager::_region_array = NULL;
54
55 ParCompactionManager::ParCompactionManager() :
56 _action(CopyAndUpdate) {
57
58 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
59
60 _old_gen = heap->old_gen();
61 _start_array = old_gen()->start_array();
62
63 marking_stack()->initialize();
64 _objarray_stack.initialize();
65 _region_stack.initialize();
66
67 reset_bitmap_query_cache();
68 }
69
70 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
71 assert(PSParallelCompact::gc_task_manager() != NULL,
72 "Needed for initialization");
73
74 _mark_bitmap = mbm;
75
76 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();
77
78 assert(_manager_array == NULL, "Attempt to initialize twice");
79 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC);
80 guarantee(_manager_array != NULL, "Could not allocate manager_array");
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(PSParallelCompact::gc_task_manager()->workers() != 0,
104 "Not initialized?");
105 }
106
107 void ParCompactionManager::reset_all_bitmap_query_caches() {
108 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();
109 for (uint i=0; i<=parallel_gc_threads; i++) {
110 _manager_array[i]->reset_bitmap_query_cache();
111 }
112 }
113
114 bool ParCompactionManager::should_update() {
115 assert(action() != NotValid, "Action is not set");
116 return (action() == ParCompactionManager::Update) ||
117 (action() == ParCompactionManager::CopyAndUpdate) ||
118 (action() == ParCompactionManager::UpdateAndCopy);
119 }
120
121 bool ParCompactionManager::should_copy() {
122 assert(action() != NotValid, "Action is not set");
123 return (action() == ParCompactionManager::Copy) ||
124 (action() == ParCompactionManager::CopyAndUpdate) ||
125 (action() == ParCompactionManager::UpdateAndCopy);
126 }
127
128 ParCompactionManager*
129 ParCompactionManager::gc_thread_compaction_manager(uint index) {
130 assert(index < ParallelGCThreads, "index out of range");
131 assert(_manager_array != NULL, "Sanity");
132 return _manager_array[index];
133 }
134
135 void InstanceKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
136 assert(obj != NULL, "can't follow the content of NULL object");
137
138 cm->follow_klass(this);
139 // Only mark the header and let the scan of the meta-data mark
140 // everything else.
141
142 ParCompactionManager::MarkAndPushClosure cl(cm);
143 if (UseCompressedOops) {
144 InstanceKlass::oop_oop_iterate_oop_maps<narrowOop>(obj, &cl);
145 } else {
146 InstanceKlass::oop_oop_iterate_oop_maps<oop>(obj, &cl);
147 }
148 }
149
150 void InstanceMirrorKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
151 InstanceKlass::oop_pc_follow_contents(obj, cm);
152
153 // Follow the klass field in the mirror.
154 Klass* klass = java_lang_Class::as_Klass(obj);
155 if (klass != NULL) {
156 // An unsafe anonymous class doesn't have its own class loader,
157 // so the call to follow_klass will mark and push its java mirror instead of the
158 // class loader. When handling the java mirror for an unsafe anonymous
159 // class we need to make sure its class loader data is claimed, this is done
160 // by calling follow_class_loader explicitly. For non-anonymous classes the
161 // call to follow_class_loader is made when the class loader itself is handled.
162 if (klass->is_instance_klass() &&
163 InstanceKlass::cast(klass)->is_unsafe_anonymous()) {
164 cm->follow_class_loader(klass->class_loader_data());
165 } else {
166 cm->follow_klass(klass);
167 }
168 } else {
169 // If klass is NULL then this a mirror for a primitive type.
170 // We don't have to follow them, since they are handled as strong
171 // roots in Universe::oops_do.
172 assert(java_lang_Class::is_primitive(obj), "Sanity check");
173 }
174
175 ParCompactionManager::MarkAndPushClosure cl(cm);
176 if (UseCompressedOops) {
177 oop_oop_iterate_statics<narrowOop>(obj, &cl);
178 } else {
179 oop_oop_iterate_statics<oop>(obj, &cl);
180 }
181 }
182
183 void InstanceClassLoaderKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
184 InstanceKlass::oop_pc_follow_contents(obj, cm);
185
186 ClassLoaderData * const loader_data = java_lang_ClassLoader::loader_data(obj);
187 if (loader_data != NULL) {
188 cm->follow_class_loader(loader_data);
189 }
190 }
191
192 template <class T>
193 static void oop_pc_follow_contents_specialized(InstanceRefKlass* klass, oop obj, ParCompactionManager* cm) {
194 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr_raw(obj);
195 T heap_oop = RawAccess<>::oop_load(referent_addr);
196 log_develop_trace(gc, ref)("InstanceRefKlass::oop_pc_follow_contents " PTR_FORMAT, p2i(obj));
197 if (!CompressedOops::is_null(heap_oop)) {
198 oop referent = CompressedOops::decode_not_null(heap_oop);
199 if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) &&
200 PSParallelCompact::ref_processor()->discover_reference(obj, klass->reference_type())) {
201 // reference already enqueued, referent will be traversed later
202 klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
203 log_develop_trace(gc, ref)(" Non NULL enqueued " PTR_FORMAT, p2i(obj));
204 return;
205 } else {
206 // treat referent as normal oop
207 log_develop_trace(gc, ref)(" Non NULL normal " PTR_FORMAT, p2i(obj));
208 cm->mark_and_push(referent_addr);
209 }
210 }
211 // Treat discovered as normal oop.
212 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr_raw(obj);
213 cm->mark_and_push(discovered_addr);
214 klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
215 }
216
217
218 void InstanceRefKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
219 if (UseCompressedOops) {
220 oop_pc_follow_contents_specialized<narrowOop>(this, obj, cm);
221 } else {
222 oop_pc_follow_contents_specialized<oop>(this, obj, cm);
223 }
224 }
225
226 void ObjArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
227 cm->follow_klass(this);
228
229 if (UseCompressedOops) {
230 oop_pc_follow_contents_specialized<narrowOop>(objArrayOop(obj), 0, cm);
231 } else {
232 oop_pc_follow_contents_specialized<oop>(objArrayOop(obj), 0, cm);
233 }
234 }
235
236 void TypeArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
237 assert(obj->is_typeArray(),"must be a type array");
238 // Performance tweak: We skip iterating over the klass pointer since we
239 // know that Universe::TypeArrayKlass never moves.
240 }
241
242 void ParCompactionManager::follow_marking_stacks() {
243 do {
244 // Drain the overflow stack first, to allow stealing from the marking stack.
245 oop obj;
246 while (marking_stack()->pop_overflow(obj)) {
247 follow_contents(obj);
248 }
249 while (marking_stack()->pop_local(obj)) {
250 follow_contents(obj);
251 }
252
253 // Process ObjArrays one at a time to avoid marking stack bloat.
254 ObjArrayTask task;
255 if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
256 follow_contents((objArrayOop)task.obj(), task.index());
257 }
258 } while (!marking_stacks_empty());
259
260 assert(marking_stacks_empty(), "Sanity");
261 }
262
263 void ParCompactionManager::drain_region_stacks() {
264 do {
265 // Drain overflow stack first so other threads can steal.
266 size_t region_index;
267 while (region_stack()->pop_overflow(region_index)) {
268 PSParallelCompact::fill_and_update_region(this, region_index);
269 }
270
271 while (region_stack()->pop_local(region_index)) {
272 PSParallelCompact::fill_and_update_region(this, region_index);
273 }
274 } while (!region_stack()->is_empty());
275 }