1 /*
2 * Copyright (c) 2005, 2016, 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 volatile 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 reset_bitmap_query_cache();
73 }
74
75 ParCompactionManager::~ParCompactionManager() {
76 delete _recycled_stack_index;
77 }
78
79 void ParCompactionManager::initialize(ParMarkBitMap* mbm) {
80 assert(PSParallelCompact::gc_task_manager() != NULL,
81 "Needed for initialization");
82
83 _mark_bitmap = mbm;
84
85 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();
86
87 assert(_manager_array == NULL, "Attempt to initialize twice");
88 _manager_array = NEW_C_HEAP_ARRAY(ParCompactionManager*, parallel_gc_threads+1, mtGC);
89 guarantee(_manager_array != NULL, "Could not allocate manager_array");
90
91 _region_list = NEW_C_HEAP_ARRAY(RegionTaskQueue*,
92 parallel_gc_threads+1, mtGC);
93 guarantee(_region_list != NULL, "Could not initialize promotion manager");
94
95 _recycled_stack_index = NEW_C_HEAP_ARRAY(uint, parallel_gc_threads, mtGC);
96
97 // parallel_gc-threads + 1 to be consistent with the number of
98 // compaction managers.
99 for(uint i=0; i<parallel_gc_threads + 1; i++) {
100 _region_list[i] = new RegionTaskQueue();
101 region_list(i)->initialize();
102 }
103
104 _stack_array = new OopTaskQueueSet(parallel_gc_threads);
105 guarantee(_stack_array != NULL, "Could not allocate stack_array");
106 _objarray_queues = new ObjArrayTaskQueueSet(parallel_gc_threads);
107 guarantee(_objarray_queues != NULL, "Could not allocate objarray_queues");
108 _region_array = new RegionTaskQueueSet(parallel_gc_threads);
109 guarantee(_region_array != NULL, "Could not allocate region_array");
110
111 // Create and register the ParCompactionManager(s) for the worker threads.
112 for(uint i=0; i<parallel_gc_threads; i++) {
113 _manager_array[i] = new ParCompactionManager();
114 guarantee(_manager_array[i] != NULL, "Could not create ParCompactionManager");
115 stack_array()->register_queue(i, _manager_array[i]->marking_stack());
116 _objarray_queues->register_queue(i, &_manager_array[i]->_objarray_stack);
117 region_array()->register_queue(i, region_list(i));
118 }
119
120 // The VMThread gets its own ParCompactionManager, which is not available
121 // for work stealing.
122 _manager_array[parallel_gc_threads] = new ParCompactionManager();
123 guarantee(_manager_array[parallel_gc_threads] != NULL,
124 "Could not create ParCompactionManager");
125 assert(PSParallelCompact::gc_task_manager()->workers() != 0,
126 "Not initialized?");
127 }
128
129 void ParCompactionManager::reset_all_bitmap_query_caches() {
130 uint parallel_gc_threads = PSParallelCompact::gc_task_manager()->workers();
131 for (uint i=0; i<=parallel_gc_threads; i++) {
132 _manager_array[i]->reset_bitmap_query_cache();
133 }
134 }
135
136 int ParCompactionManager::pop_recycled_stack_index() {
137 assert(_recycled_bottom <= _recycled_top, "list is empty");
138 // Get the next available index
139 if (_recycled_bottom < _recycled_top) {
140 uint cur, next, last;
141 do {
142 cur = _recycled_bottom;
143 next = cur + 1;
144 last = Atomic::cmpxchg(next, &_recycled_bottom, cur);
145 } while (cur != last);
146 return _recycled_stack_index[next];
147 } else {
148 return -1;
149 }
150 }
151
152 void ParCompactionManager::push_recycled_stack_index(uint v) {
153 // Get the next available index
154 int cur = Atomic::add(1, &_recycled_top);
155 _recycled_stack_index[cur] = v;
156 assert(_recycled_bottom <= _recycled_top, "list top and bottom are wrong");
157 }
158
159 bool ParCompactionManager::should_update() {
160 assert(action() != NotValid, "Action is not set");
161 return (action() == ParCompactionManager::Update) ||
162 (action() == ParCompactionManager::CopyAndUpdate) ||
163 (action() == ParCompactionManager::UpdateAndCopy);
164 }
165
166 bool ParCompactionManager::should_copy() {
167 assert(action() != NotValid, "Action is not set");
168 return (action() == ParCompactionManager::Copy) ||
169 (action() == ParCompactionManager::CopyAndUpdate) ||
170 (action() == ParCompactionManager::UpdateAndCopy);
171 }
172
173 void ParCompactionManager::region_list_push(uint list_index,
174 size_t region_index) {
175 region_list(list_index)->push(region_index);
176 }
177
178 void ParCompactionManager::verify_region_list_empty(uint list_index) {
179 assert(region_list(list_index)->is_empty(), "Not empty");
180 }
181
182 ParCompactionManager*
183 ParCompactionManager::gc_thread_compaction_manager(uint index) {
184 assert(index < ParallelGCThreads, "index out of range");
185 assert(_manager_array != NULL, "Sanity");
186 return _manager_array[index];
187 }
188
189 void InstanceKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
190 assert(obj != NULL, "can't follow the content of NULL object");
191
192 cm->follow_klass(this);
193 // Only mark the header and let the scan of the meta-data mark
194 // everything else.
195
196 ParCompactionManager::MarkAndPushClosure cl(cm);
197 InstanceKlass::oop_oop_iterate_oop_maps<true>(obj, &cl);
198 }
199
200 void InstanceMirrorKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
201 InstanceKlass::oop_pc_follow_contents(obj, cm);
202
203 // Follow the klass field in the mirror.
204 Klass* klass = java_lang_Class::as_Klass(obj);
205 if (klass != NULL) {
206 // An anonymous class doesn't have its own class loader, so the call
207 // to follow_klass will mark and push its java mirror instead of the
208 // class loader. When handling the java mirror for an anonymous class
209 // we need to make sure its class loader data is claimed, this is done
210 // by calling follow_class_loader explicitly. For non-anonymous classes
211 // the call to follow_class_loader is made when the class loader itself
212 // is handled.
213 if (klass->is_instance_klass() && InstanceKlass::cast(klass)->is_anonymous()) {
214 cm->follow_class_loader(klass->class_loader_data());
215 } else {
216 cm->follow_klass(klass);
217 }
218 } else {
219 // If klass is NULL then this a mirror for a primitive type.
220 // We don't have to follow them, since they are handled as strong
221 // roots in Universe::oops_do.
222 assert(java_lang_Class::is_primitive(obj), "Sanity check");
223 }
224
225 ParCompactionManager::MarkAndPushClosure cl(cm);
226 oop_oop_iterate_statics<true>(obj, &cl);
227 }
228
229 void InstanceClassLoaderKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
230 InstanceKlass::oop_pc_follow_contents(obj, cm);
231
232 ClassLoaderData * const loader_data = java_lang_ClassLoader::loader_data(obj);
233 if (loader_data != NULL) {
234 cm->follow_class_loader(loader_data);
235 }
236 }
237
238 template <class T>
239 static void oop_pc_follow_contents_specialized(InstanceRefKlass* klass, oop obj, ParCompactionManager* cm) {
240 T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
241 T heap_oop = oopDesc::load_heap_oop(referent_addr);
242 log_develop_trace(gc, ref)("InstanceRefKlass::oop_pc_follow_contents " PTR_FORMAT, p2i(obj));
243 if (!oopDesc::is_null(heap_oop)) {
244 oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
245 if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) &&
246 PSParallelCompact::ref_processor()->discover_reference(obj, klass->reference_type())) {
247 // reference already enqueued, referent will be traversed later
248 klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
249 log_develop_trace(gc, ref)(" Non NULL enqueued " PTR_FORMAT, p2i(obj));
250 return;
251 } else {
252 // treat referent as normal oop
253 log_develop_trace(gc, ref)(" Non NULL normal " PTR_FORMAT, p2i(obj));
254 cm->mark_and_push(referent_addr);
255 }
256 }
257 T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
258 // Treat discovered as normal oop, if ref is not "active",
259 // i.e. if next is non-NULL.
260 T next_oop = oopDesc::load_heap_oop(next_addr);
261 if (!oopDesc::is_null(next_oop)) { // i.e. ref is not "active"
262 T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
263 log_develop_trace(gc, ref)(" Process discovered as normal " PTR_FORMAT, p2i(discovered_addr));
264 cm->mark_and_push(discovered_addr);
265 }
266 cm->mark_and_push(next_addr);
267 klass->InstanceKlass::oop_pc_follow_contents(obj, cm);
268 }
269
270
271 void InstanceRefKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
272 if (UseCompressedOops) {
273 oop_pc_follow_contents_specialized<narrowOop>(this, obj, cm);
274 } else {
275 oop_pc_follow_contents_specialized<oop>(this, obj, cm);
276 }
277 }
278
279 void ObjArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
280 cm->follow_klass(this);
281
282 if (UseCompressedOops) {
283 oop_pc_follow_contents_specialized<narrowOop>(objArrayOop(obj), 0, cm);
284 } else {
285 oop_pc_follow_contents_specialized<oop>(objArrayOop(obj), 0, cm);
286 }
287 }
288
289 void TypeArrayKlass::oop_pc_follow_contents(oop obj, ParCompactionManager* cm) {
290 assert(obj->is_typeArray(),"must be a type array");
291 // Performance tweak: We skip iterating over the klass pointer since we
292 // know that Universe::TypeArrayKlass never moves.
293 }
294
295 void ParCompactionManager::follow_marking_stacks() {
296 do {
297 // Drain the overflow stack first, to allow stealing from the marking stack.
298 oop obj;
299 while (marking_stack()->pop_overflow(obj)) {
300 follow_contents(obj);
301 }
302 while (marking_stack()->pop_local(obj)) {
303 follow_contents(obj);
304 }
305
306 // Process ObjArrays one at a time to avoid marking stack bloat.
307 ObjArrayTask task;
308 if (_objarray_stack.pop_overflow(task) || _objarray_stack.pop_local(task)) {
309 follow_contents((objArrayOop)task.obj(), task.index());
310 }
311 } while (!marking_stacks_empty());
312
313 assert(marking_stacks_empty(), "Sanity");
314 }
315
316 void ParCompactionManager::drain_region_stacks() {
317 do {
318 // Drain overflow stack first so other threads can steal.
319 size_t region_index;
320 while (region_stack()->pop_overflow(region_index)) {
321 PSParallelCompact::fill_and_update_region(this, region_index);
322 }
323
324 while (region_stack()->pop_local(region_index)) {
325 PSParallelCompact::fill_and_update_region(this, region_index);
326 }
327 } while (!region_stack()->is_empty());
328 }