1 /*
2 * Copyright (c) 2005, 2015, 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.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.inline.hpp"
42
43 PSOldGen* ParCompactionManager::_old_gen = NULL;
44 ParCompactionManager** ParCompactionManager::_manager_array = NULL;
45
46 RegionTaskQueue** ParCompactionManager::_region_list = 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 uint* ParCompactionManager::_recycled_stack_index = NULL;
56 int ParCompactionManager::_recycled_top = -1;
57 int ParCompactionManager::_recycled_bottom = -1;
58
59 ParCompactionManager::ParCompactionManager() :
60 _action(CopyAndUpdate),
61 _region_stack(NULL),
62 _region_stack_index((uint)max_uintx) {
63
64 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
65
66 _old_gen = heap->old_gen();
67 _start_array = old_gen()->start_array();
68
69 marking_stack()->initialize();
70 _objarray_stack.initialize();
71 }
72
73 ParCompactionManager::~ParCompactionManager() {
74 delete _recycled_stack_index;
75 }
76
77 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
78 assert(PSParallelCompact::gc_task_manager() != NULL,
79 "Needed for initialization");
80
81 _mark_bitmap = mbm;
82
83 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();
84
85 assert(_manager_array == NULL, "Attempt to initialize twice");
86 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC);
87 guarantee(_manager_array != NULL, "Could not allocate manager_array");
88
89 _region_list = NEW_C_HEAP_ARRAY(RegionTaskQueue*,
90 parallel_gc_threads+1, mtGC);
91 guarantee(_region_list != NULL, "Could not initialize promotion manager");
92
93 _recycled_stack_index = NEW_C_HEAP_ARRAY(uint, parallel_gc_threads, mtGC);
94
95 // parallel_gc-threads + 1 to be consistent with the number of
96 // compaction managers.
97 for(uint i=0; i<parallel_gc_threads + 1; i++) {
98 _region_list[i] = new RegionTaskQueue();
99 region_list(i)->initialize();
100 }
101
102 _stack_array = new OopTaskQueueSet(parallel_gc_threads);
103 guarantee(_stack_array != NULL, "Could not allocate stack_array");
104 _objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
105 guarantee(_objarray_queues != NULL, "Could not allocate objarray_queues");
106 _region_array = new RegionTaskQueueSet(parallel_gc_threads);
107 guarantee(_region_array != NULL, "Could not allocate region_array");
108
109 // Create and register the ParCompactionManager(s) for the worker threads.
110 for(uint i=0; i<parallel_gc_threads; i++) {
111 _manager_array[i] = new ParCompactionManager();
112 guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");
113 stack_array()->register_queue(i, _manager_array[i]->marking_stack());
114 _objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
115 region_array()->register_queue(i, region_list(i));
116 }
117
118 // The VMThread gets its own ParCompactionManager, which is not available
119 // for work stealing.
120 _manager_array[parallel_gc_threads] = new ParCompactionManager();
121 guarantee(_manager_array[parallel_gc_threads] != NULL,
122 "Could not create ParCompactionManager");
123 assert(PSParallelCompact::gc_task_manager()->workers() != 0,
124 "Not initialized?");
125 }
126
127 int ParCompactionManager::pop_recycled_stack_index() {
128 assert(_recycled_bottom <= _recycled_top, "list is empty");
129 // Get the next available index
130 if (_recycled_bottom < _recycled_top) {
131 uint cur, next, last;
132 do {
133 cur = _recycled_bottom;
134 next = cur + 1;
135 last = Atomic::cmpxchg(next, &_recycled_bottom, cur);
136 } while (cur != last);
137 return _recycled_stack_index[next];
138 } else {
139 return -1;
140 }
141 }
142
143 void ParCompactionManager::push_recycled_stack_index(uint v) {
144 // Get the next available index
145 int cur = Atomic::add(1, &_recycled_top);
146 _recycled_stack_index[cur] = v;
147 assert(_recycled_bottom <= _recycled_top, "list top and bottom are wrong");
148 }
149
150 bool ParCompactionManager::should_update() {
151 assert(action() != NotValid, "Action is not set");
152 return (action() == ParCompactionManager::Update) ||
153 (action() == ParCompactionManager::CopyAndUpdate) ||
154 (action() == ParCompactionManager::UpdateAndCopy);
155 }
156
157 bool ParCompactionManager::should_copy() {
158 assert(action() != NotValid, "Action is not set");
159 return (action() == ParCompactionManager::Copy) ||
160 (action() == ParCompactionManager::CopyAndUpdate) ||
161 (action() == ParCompactionManager::UpdateAndCopy);
162 }
163
164 void ParCompactionManager::region_list_push(uint list_index,
165 size_t region_index) {
166 region_list(list_index)->push(region_index);
167 }
168
169 void ParCompactionManager::verify_region_list_empty(uint list_index) {
170 assert(region_list(list_index)->is_empty(), "Not empty");
171 }
172
173 ParCompactionManager*
174 ParCompactionManager::gc_thread_compaction_manager(uint index) {
175 assert(index < ParallelGCThreads, "index out of range");
176 assert(_manager_array != NULL, "Sanity");
177 return _manager_array[index];
178 }
179
180 void InstanceKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
181 assert(obj != NULL, "can't follow the content of NULL object");
182
183 cm->follow_klass(this);
184 // Only mark the header and let the scan of the meta-data mark
185 // everything else.
186
187 ParCompactionManager::MarkAndPushClosure cl(cm);
188 InstanceKlass::oop_oop_iterate_oop_maps<true>(obj, &cl);
189 }
190
191 void InstanceMirrorKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
192 InstanceKlass::oop_pc_follow_contents(obj, cm);
193
194 // Follow the klass field in the mirror.
195 Klass* klass = java_lang_Class::as_Klass(obj);
196 if (klass != NULL) {
197 // An anonymous class doesn't have its own class loader, so the call
198 // to follow_klass will mark and push its java mirror instead of the
199 // class loader. When handling the java mirror for an anonymous class
200 // we need to make sure its class loader data is claimed, this is done
201 // by calling follow_class_loader explicitly. For non-anonymous classes
202 // the call to follow_class_loader is made when the class loader itself
203 // is handled.
204 if (klass->is_instance_klass() && InstanceKlass::cast(klass)->is_anonymous()) {
205 cm->follow_class_loader(klass->class_loader_data());
206 } else {
207 cm->follow_klass(klass);
208 }
209 } else {
210 // If klass is NULL then this a mirror for a primitive type.
211 // We don't have to follow them, since they are handled as strong
212 // roots in Universe::oops_do.
213 assert(java_lang_Class::is_primitive(obj), "Sanity check");
214 }
215
216 ParCompactionManager::MarkAndPushClosure cl(cm);
217 oop_oop_iterate_statics<true>(obj, &cl);
218 }
219
220 void InstanceClassLoaderKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
221 InstanceKlass::oop_pc_follow_contents(obj, cm);
222
223 ClassLoaderData * const loader_data = java_lang_ClassLoader::loader_data(obj);
224 if (loader_data != NULL) {
225 cm->follow_class_loader(loader_data);
226 }
227 }
228
229 template <class T>
230 static void oop_pc_follow_contents_specialized(InstanceRefKlass* klass, oop obj, ParCompactionManager* cm) {
231 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
232 T heap_oop = oopDesc::load_heap_oop(referent_addr);
233 log_develop_trace(gc, ref)("InstanceRefKlass::oop_pc_follow_contents " PTR_FORMAT, p2i(obj));
234 if (!oopDesc::is_null(heap_oop)) {
235 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
236 if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) &&
237 PSParallelCompact::ref_processor()->discover_reference(obj, klass->reference_type())) {
238 // reference already enqueued, referent will be traversed later
239 klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
240 log_develop_trace(gc, ref)(" Non NULL enqueued " PTR_FORMAT, p2i(obj));
241 return;
242 } else {
243 // treat referent as normal oop
244 log_develop_trace(gc, ref)(" Non NULL normal " PTR_FORMAT, p2i(obj));
245 cm->mark_and_push(referent_addr);
246 }
247 }
248 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
249 // Treat discovered as normal oop, if ref is not "active",
250 // i.e. if next is non-NULL.
251 T next_oop = oopDesc::load_heap_oop(next_addr);
252 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active"
253 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
254 log_develop_trace(gc, ref)(" Process discovered as normal " PTR_FORMAT, p2i(discovered_addr));
255 cm->mark_and_push(discovered_addr);
256 }
257 cm->mark_and_push(next_addr);
258 klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
259 }
260
261
262 void InstanceRefKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
263 if (UseCompressedOops) {
264 oop_pc_follow_contents_specialized<narrowOop>(this, obj, cm);
265 } else {
266 oop_pc_follow_contents_specialized<oop>(this, obj, cm);
267 }
268 }
269
270 void ObjArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
271 cm->follow_klass(this);
272
273 if (UseCompressedOops) {
274 oop_pc_follow_contents_specialized<narrowOop>(objArrayOop(obj), 0, cm);
275 } else {
276 oop_pc_follow_contents_specialized<oop>(objArrayOop(obj), 0, cm);
277 }
278 }
279
280 void TypeArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
281 assert(obj->is_typeArray(),"must be a type array");
282 // Performance tweak: We skip iterating over the klass pointer since we
283 // know that Universe::TypeArrayKlass never moves.
284 }
285
286 void ParCompactionManager::follow_marking_stacks() {
287 do {
288 // Drain the overflow stack first, to allow stealing from the marking stack.
289 oop obj;
290 while (marking_stack()->pop_overflow(obj)) {
291 follow_contents(obj);
292 }
293 while (marking_stack()->pop_local(obj)) {
294 follow_contents(obj);
295 }
296
297 // Process ObjArrays one at a time to avoid marking stack bloat.
298 ObjArrayTask task;
299 if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
300 follow_contents((objArrayOop)task.obj(), task.index());
301 }
302 } while (!marking_stacks_empty());
303
304 assert(marking_stacks_empty(), "Sanity");
305 }
306
307 void ParCompactionManager::drain_region_stacks() {
308 do {
309 // Drain overflow stack first so other threads can steal.
310 size_t region_index;
311 while (region_stack()->pop_overflow(region_index)) {
312 PSParallelCompact::fill_and_update_region(this, region_index);
313 }
314
315 while (region_stack()->pop_local(region_index)) {
316 PSParallelCompact::fill_and_update_region(this, region_index);
317 }
318 } while (!region_stack()->is_empty());
319 }