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/instanceKlass.inline.hpp"
38 #include "oops/instanceMirrorKlass.inline.hpp"
39 #include "oops/objArrayKlass.inline.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "runtime/atomic.hpp"
42
43 PSOldGen* ParCompactionManager::_old_gen = NULL;
44 ParCompactionManager** ParCompactionManager::_manager_array = NULL;
45
46 OopTaskQueueSet* ParCompactionManager::_stack_array = NULL;
47 ParCompactionManager::ObjArrayTaskQueueSet*
48 ParCompactionManager::_objarray_queues = NULL;
49 ObjectStartArray* ParCompactionManager::_start_array = NULL;
50 ParMarkBitMap* ParCompactionManager::_mark_bitmap = NULL;
51 RegionTaskQueueSet* ParCompactionManager::_region_array = NULL;
52
53 ParCompactionManager::ParCompactionManager() :
54 _action(CopyAndUpdate) {
55
56 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
57
58 _old_gen = heap->old_gen();
59 _start_array = old_gen()->start_array();
60
61 marking_stack()->initialize();
62 _objarray_stack.initialize();
63 _region_stack.initialize();
64
65 reset_bitmap_query_cache();
66 }
67
68 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
69 assert(PSParallelCompact::gc_task_manager() != NULL,
70 "Needed for initialization");
71
72 _mark_bitmap = mbm;
73
74 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();
75
76 assert(_manager_array == NULL, "Attempt to initialize twice");
77 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC);
78 guarantee(_manager_array != NULL, "Could not allocate manager_array");
79
80 _stack_array = new OopTaskQueueSet(parallel_gc_threads);
81 guarantee(_stack_array != NULL, "Could not allocate stack_array");
82 _objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
83 guarantee(_objarray_queues != NULL, "Could not allocate objarray_queues");
84 _region_array = new RegionTaskQueueSet(parallel_gc_threads);
85 guarantee(_region_array != NULL, "Could not allocate region_array");
86
87 // Create and register the ParCompactionManager(s) for the worker threads.
88 for(uint i=0; i<parallel_gc_threads; i++) {
89 _manager_array[i] = new ParCompactionManager();
90 guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");
91 stack_array()->register_queue(i, _manager_array[i]->marking_stack());
92 _objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
93 region_array()->register_queue(i, _manager_array[i]->region_stack());
94 }
95
96 // The VMThread gets its own ParCompactionManager, which is not available
97 // for work stealing.
98 _manager_array[parallel_gc_threads] = new ParCompactionManager();
99 guarantee(_manager_array[parallel_gc_threads] != NULL,
100 "Could not create ParCompactionManager");
101 assert(PSParallelCompact::gc_task_manager()->workers() != 0,
102 "Not initialized?");
103 }
104
105 void ParCompactionManager::reset_all_bitmap_query_caches() {
106 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();
107 for (uint i=0; i<=parallel_gc_threads; i++) {
108 _manager_array[i]->reset_bitmap_query_cache();
109 }
110 }
111
112 bool ParCompactionManager::should_update() {
113 assert(action() != NotValid, "Action is not set");
114 return (action() == ParCompactionManager::Update) ||
115 (action() == ParCompactionManager::CopyAndUpdate) ||
116 (action() == ParCompactionManager::UpdateAndCopy);
117 }
118
119 bool ParCompactionManager::should_copy() {
120 assert(action() != NotValid, "Action is not set");
121 return (action() == ParCompactionManager::Copy) ||
122 (action() == ParCompactionManager::CopyAndUpdate) ||
123 (action() == ParCompactionManager::UpdateAndCopy);
124 }
125
126 ParCompactionManager*
127 ParCompactionManager::gc_thread_compaction_manager(uint index) {
128 assert(index < ParallelGCThreads, "index out of range");
129 assert(_manager_array != NULL, "Sanity");
130 return _manager_array[index];
131 }
132
133 void InstanceKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
134 assert(obj != NULL, "can't follow the content of NULL object");
135
136 cm->follow_klass(this);
137 // Only mark the header and let the scan of the meta-data mark
138 // everything else.
139
140 ParCompactionManager::MarkAndPushClosure cl(cm);
141 InstanceKlass::oop_oop_iterate_oop_maps<true>(obj, &cl);
142 }
143
144 void InstanceMirrorKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
145 InstanceKlass::oop_pc_follow_contents(obj, cm);
146
147 // Follow the klass field in the mirror.
148 Klass* klass = java_lang_Class::as_Klass(obj);
149 if (klass != NULL) {
150 // An anonymous class doesn't have its own class loader, so the call
151 // to follow_klass will mark and push its java mirror instead of the
152 // class loader. When handling the java mirror for an anonymous class
153 // we need to make sure its class loader data is claimed, this is done
154 // by calling follow_class_loader explicitly. For non-anonymous classes
155 // the call to follow_class_loader is made when the class loader itself
156 // is handled.
157 if (klass->is_instance_klass() && InstanceKlass::cast(klass)->is_anonymous()) {
158 cm->follow_class_loader(klass->class_loader_data());
159 } else {
160 cm->follow_klass(klass);
161 }
162 } else {
163 // If klass is NULL then this a mirror for a primitive type.
164 // We don't have to follow them, since they are handled as strong
165 // roots in Universe::oops_do.
166 assert(java_lang_Class::is_primitive(obj), "Sanity check");
167 }
168
169 ParCompactionManager::MarkAndPushClosure cl(cm);
170 oop_oop_iterate_statics<true>(obj, &cl);
171 }
172
173 void InstanceClassLoaderKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
174 InstanceKlass::oop_pc_follow_contents(obj, cm);
175
176 ClassLoaderData * const loader_data = java_lang_ClassLoader::loader_data(obj);
177 if (loader_data != NULL) {
178 cm->follow_class_loader(loader_data);
179 }
180 }
181
182 template <class T>
183 static void oop_pc_follow_contents_specialized(InstanceRefKlass* klass, oop obj, ParCompactionManager* cm) {
184 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr_raw(obj);
185 T heap_oop = oopDesc::load_heap_oop(referent_addr);
186 log_develop_trace(gc, ref)("InstanceRefKlass::oop_pc_follow_contents " PTR_FORMAT, p2i(obj));
187 if (!oopDesc::is_null(heap_oop)) {
188 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
189 if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) &&
190 PSParallelCompact::ref_processor()->discover_reference(obj, klass->reference_type())) {
191 // reference already enqueued, referent will be traversed later
192 klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
193 log_develop_trace(gc, ref)(" Non NULL enqueued " PTR_FORMAT, p2i(obj));
194 return;
195 } else {
196 // treat referent as normal oop
197 log_develop_trace(gc, ref)(" Non NULL normal " PTR_FORMAT, p2i(obj));
198 cm->mark_and_push(referent_addr);
199 }
200 }
201 T* next_addr = (T*)java_lang_ref_Reference::next_addr_raw(obj);
202 // Treat discovered as normal oop, if ref is not "active",
203 // i.e. if next is non-NULL.
204 T next_oop = oopDesc::load_heap_oop(next_addr);
205 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active"
206 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr_raw(obj);
207 log_develop_trace(gc, ref)(" Process discovered as normal " PTR_FORMAT, p2i(discovered_addr));
208 cm->mark_and_push(discovered_addr);
209 }
210 cm->mark_and_push(next_addr);
211 klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
212 }
213
214
215 void InstanceRefKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
216 if (UseCompressedOops) {
217 oop_pc_follow_contents_specialized<narrowOop>(this, obj, cm);
218 } else {
219 oop_pc_follow_contents_specialized<oop>(this, obj, cm);
220 }
221 }
222
223 void ObjArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
224 cm->follow_klass(this);
225
226 if (UseCompressedOops) {
227 oop_pc_follow_contents_specialized<narrowOop>(objArrayOop(obj), 0, cm);
228 } else {
229 oop_pc_follow_contents_specialized<oop>(objArrayOop(obj), 0, cm);
230 }
231 }
232
233 void TypeArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
234 assert(obj->is_typeArray(),"must be a type array");
235 // Performance tweak: We skip iterating over the klass pointer since we
236 // know that Universe::TypeArrayKlass never moves.
237 }
238
239 void ParCompactionManager::follow_marking_stacks() {
240 do {
241 // Drain the overflow stack first, to allow stealing from the marking stack.
242 oop obj;
243 while (marking_stack()->pop_overflow(obj)) {
244 follow_contents(obj);
245 }
246 while (marking_stack()->pop_local(obj)) {
247 follow_contents(obj);
248 }
249
250 // Process ObjArrays one at a time to avoid marking stack bloat.
251 ObjArrayTask task;
252 if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
253 follow_contents((objArrayOop)task.obj(), task.index());
254 }
255 } while (!marking_stacks_empty());
256
257 assert(marking_stacks_empty(), "Sanity");
258 }
259
260 void ParCompactionManager::drain_region_stacks() {
261 do {
262 // Drain overflow stack first so other threads can steal.
263 size_t region_index;
264 while (region_stack()->pop_overflow(region_index)) {
265 PSParallelCompact::fill_and_update_region(this, region_index);
266 }
267
268 while (region_stack()->pop_local(region_index)) {
269 PSParallelCompact::fill_and_update_region(this, region_index);
270 }
271 } while (!region_stack()->is_empty());
272 }