1 /*
2 * Copyright (c) 2005, 2010, 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 "incls/_precompiled.incl"
26 #include "incls/_psCompactionManager.cpp.incl"
27
28 PSOldGen* ParCompactionManager::_old_gen = NULL;
29 ParCompactionManager** ParCompactionManager::_manager_array = NULL;
30 OopTaskQueueSet* ParCompactionManager::_stack_array = NULL;
31 ParCompactionManager::ObjArrayTaskQueueSet*
32 ParCompactionManager::_objarray_queues = NULL;
33 ObjectStartArray* ParCompactionManager::_start_array = NULL;
34 ParMarkBitMap* ParCompactionManager::_mark_bitmap = NULL;
35 RegionTaskQueueSet* ParCompactionManager::_region_array = NULL;
36
37 ParCompactionManager::ParCompactionManager() :
38 _action(CopyAndUpdate) {
39
40 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
41 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
42
43 _old_gen = heap->old_gen();
44 _start_array = old_gen()->start_array();
45
46 marking_stack()->initialize();
47 _objarray_stack.initialize();
48 region_stack()->initialize();
49
50 // Note that _revisit_klass_stack is allocated out of the
51 // C heap (as opposed to out of ResourceArena).
52 int size =
53 (SystemDictionary::number_of_classes() * 2) * 2 / ParallelGCThreads;
54 _revisit_klass_stack = new (ResourceObj::C_HEAP) GrowableArray<Klass*>(size, true);
55 // From some experiments (#klass/k)^2 for k = 10 seems a better fit, but this will
56 // have to do for now until we are able to investigate a more optimal setting.
57 _revisit_mdo_stack = new (ResourceObj::C_HEAP) GrowableArray<DataLayout*>(size*2, true);
58 }
59
60 ParCompactionManager::~ParCompactionManager() {
61 delete _revisit_klass_stack;
62 delete _revisit_mdo_stack;
63 // _manager_array and _stack_array are statics
64 // shared with all instances of ParCompactionManager
65 // should not be deallocated.
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 );
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 bool ParCompactionManager::should_update() {
106 assert(action() != NotValid, "Action is not set");
107 return (action() == ParCompactionManager::Update) ||
108 (action() == ParCompactionManager::CopyAndUpdate) ||
109 (action() == ParCompactionManager::UpdateAndCopy);
110 }
111
112 bool ParCompactionManager::should_copy() {
113 assert(action() != NotValid, "Action is not set");
114 return (action() == ParCompactionManager::Copy) ||
115 (action() == ParCompactionManager::CopyAndUpdate) ||
116 (action() == ParCompactionManager::UpdateAndCopy);
117 }
118
119 bool ParCompactionManager::should_verify_only() {
120 assert(action() != NotValid, "Action is not set");
121 return action() == ParCompactionManager::VerifyUpdate;
122 }
123
124 bool ParCompactionManager::should_reset_only() {
125 assert(action() != NotValid, "Action is not set");
126 return action() == ParCompactionManager::ResetObjects;
127 }
128
129 ParCompactionManager*
130 ParCompactionManager::gc_thread_compaction_manager(int index) {
131 assert(index >= 0 && index < (int)ParallelGCThreads, "index out of range");
132 assert(_manager_array != NULL, "Sanity");
133 return _manager_array[index];
134 }
135
136 void ParCompactionManager::reset() {
137 for(uint i=0; i<ParallelGCThreads+1; i++) {
138 manager_array(i)->revisit_klass_stack()->clear();
139 manager_array(i)->revisit_mdo_stack()->clear();
140 }
141 }
142
143 void ParCompactionManager::follow_marking_stacks() {
144 do {
145 // Drain the overflow stack first, to allow stealing from the marking stack.
146 oop obj;
147 while (marking_stack()->pop_overflow(obj)) {
148 obj->follow_contents(this);
149 }
150 while (marking_stack()->pop_local(obj)) {
151 obj->follow_contents(this);
152 }
153
154 // Process ObjArrays one at a time to avoid marking stack bloat.
155 ObjArrayTask task;
156 if (_objarray_stack.pop_overflow(task)) {
157 objArrayKlass* const k = (objArrayKlass*)task.obj()->blueprint();
158 k->oop_follow_contents(this, task.obj(), task.index());
159 } else if (_objarray_stack.pop_local(task)) {
160 objArrayKlass* const k = (objArrayKlass*)task.obj()->blueprint();
161 k->oop_follow_contents(this, task.obj(), task.index());
162 }
163 } while (!marking_stacks_empty());
164
165 assert(marking_stacks_empty(), "Sanity");
166 }
167
168 void ParCompactionManager::drain_region_stacks() {
169 do {
170 // Drain overflow stack first so other threads can steal.
171 size_t region_index;
172 while (region_stack()->pop_overflow(region_index)) {
173 PSParallelCompact::fill_and_update_region(this, region_index);
174 }
175
176 while (region_stack()->pop_local(region_index)) {
177 PSParallelCompact::fill_and_update_region(this, region_index);
178 }
179 } while (!region_stack()->is_empty());
180 }
181
182 #ifdef ASSERT
183 bool ParCompactionManager::stacks_have_been_allocated() {
184 return (revisit_klass_stack()->data_addr() != NULL &&
185 revisit_mdo_stack()->data_addr() != NULL);
186 }
187 #endif