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 #ifndef SHARE_VM_GC_PARALLEL_PSCOMPACTIONMANAGER_HPP
26 #define SHARE_VM_GC_PARALLEL_PSCOMPACTIONMANAGER_HPP
27
28 #include "gc/shared/taskqueue.hpp"
29 #include "memory/allocation.hpp"
30 #include "utilities/stack.hpp"
31
32 class MutableSpace;
33 class PSOldGen;
34 class ParCompactionManager;
35 class ObjectStartArray;
36 class ParallelCompactData;
37 class ParMarkBitMap;
38
39 class ParCompactionManager : public CHeapObj<mtGC> {
40 friend class ParallelTaskTerminator;
41 friend class ParMarkBitMap;
42 friend class PSParallelCompact;
43 friend class StealRegionCompactionTask;
44 friend class UpdateAndFillClosure;
45 friend class RefProcTaskExecutor;
46 friend class IdleGCTask;
47
48 public:
49
50 // ------------------------ Don't putback if not needed
51 // Actions that the compaction manager should take.
52 enum Action {
53 Update,
54 Copy,
55 UpdateAndCopy,
56 CopyAndUpdate,
57 NotValid
58 };
59 // ------------------------ End don't putback if not needed
60
61 private:
62 // 32-bit: 4K * 8 = 32KiB; 64-bit: 8K * 16 = 128KiB
63 #define QUEUE_SIZE (1 << NOT_LP64(12) LP64_ONLY(13))
64 typedef OverflowTaskQueue<ObjArrayTask, mtGC, QUEUE_SIZE> ObjArrayTaskQueue;
65 typedef GenericTaskQueueSet<ObjArrayTaskQueue, mtGC> ObjArrayTaskQueueSet;
66 #undef QUEUE_SIZE
67
68 static ParCompactionManager** _manager_array;
69 static OopTaskQueueSet* _stack_array;
70 static ObjArrayTaskQueueSet* _objarray_queues;
71 static ObjectStartArray* _start_array;
72 static RegionTaskQueueSet* _region_array;
73 static PSOldGen* _old_gen;
74
75 private:
76 OverflowTaskQueue<oop, mtGC> _marking_stack;
77 ObjArrayTaskQueue _objarray_stack;
78
79 // Is there a way to reuse the _marking_stack for the
80 // saving empty regions? For now just create a different
81 // type of TaskQueue.
82 RegionTaskQueue* _region_stack;
83
84 static RegionTaskQueue** _region_list;
85 // Index in _region_list for current _region_stack.
86 uint _region_stack_index;
87
88 // Indexes of recycled region stacks/overflow stacks
89 // Stacks of regions to be compacted are embedded in the tasks doing
90 // the compaction. A thread that executes the task extracts the
91 // region stack and drains it. These threads keep these region
92 // stacks for use during compaction task stealing. If a thread
93 // gets a second draining task, it pushed its current region stack
94 // index into the array _recycled_stack_index and gets a new
95 // region stack from the task. A thread that is executing a
96 // compaction stealing task without ever having executing a
97 // draining task, will get a region stack from _recycled_stack_index.
98 //
99 // Array of indexes into the array of region stacks.
100 static uint* _recycled_stack_index;
101 // The index into _recycled_stack_index of the last region stack index
102 // pushed. If -1, there are no entries into _recycled_stack_index.
103 static int _recycled_top;
104 // The index into _recycled_stack_index of the last region stack index
105 // popped. If -1, there has not been any entry popped.
106 static int _recycled_bottom;
107
108 static ParMarkBitMap* _mark_bitmap;
109
110 Action _action;
111
112 static PSOldGen* old_gen() { return _old_gen; }
113 static ObjectStartArray* start_array() { return _start_array; }
114 static OopTaskQueueSet* stack_array() { return _stack_array; }
115
116 static void initialize(ParMarkBitMap* mbm);
117
118 protected:
119 // Array of tasks. Needed by the ParallelTaskTerminator.
120 static RegionTaskQueueSet* region_array() { return _region_array; }
121 OverflowTaskQueue<oop, mtGC>* marking_stack() { return &_marking_stack; }
122
123 // Pushes onto the marking stack. If the marking stack is full,
124 // pushes onto the overflow stack.
125 void stack_push(oop obj);
126 // Do not implement an equivalent stack_pop. Deal with the
127 // marking stack and overflow stack directly.
128
129 public:
130 Action action() { return _action; }
131 void set_action(Action v) { _action = v; }
132
133 RegionTaskQueue* region_stack() { return _region_stack; }
134 void set_region_stack(RegionTaskQueue* v) { _region_stack = v; }
135
136 inline static ParCompactionManager* manager_array(int index);
137
138 inline static RegionTaskQueue* region_list(int index) {
139 return _region_list[index];
140 }
141
142 uint region_stack_index() { return _region_stack_index; }
143 void set_region_stack_index(uint v) { _region_stack_index = v; }
144
145 // Pop and push unique reusable stack index
146 static int pop_recycled_stack_index();
147 static void push_recycled_stack_index(uint v);
148 static void reset_recycled_stack_index() {
149 _recycled_bottom = _recycled_top = -1;
150 }
151
152 ParCompactionManager();
153 ~ParCompactionManager();
154
155 // Pushes onto the region stack at the given index. If the
156 // region stack is full,
157 // pushes onto the region overflow stack.
158 static void region_list_push(uint stack_index, size_t region_index);
159 static void verify_region_list_empty(uint stack_index);
160 ParMarkBitMap* mark_bitmap() { return _mark_bitmap; }
161
162 // void drain_stacks();
163
164 bool should_update();
165 bool should_copy();
166
167 // Save for later processing. Must not fail.
168 inline void push(oop obj);
169 inline void push_objarray(oop objarray, size_t index);
170 inline void push_region(size_t index);
171
172 // Check mark and maybe push on marking stack.
173 template <typename T> inline void mark_and_push(T* p);
174
175 inline void follow_klass(Klass* klass);
176
177 void follow_class_loader(ClassLoaderData* klass);
178
179 // Access function for compaction managers
180 static ParCompactionManager* gc_thread_compaction_manager(int index);
181
182 static bool steal(int queue_num, int* seed, oop& t);
183 static bool steal_objarray(int queue_num, int* seed, ObjArrayTask& t);
184 static bool steal(int queue_num, int* seed, size_t& region);
185
186 // Process tasks remaining on any marking stack
187 void follow_marking_stacks();
188 inline bool marking_stacks_empty() const;
189
190 // Process tasks remaining on any stack
191 void drain_region_stacks();
192
193 void follow_contents(oop obj);
194 void follow_contents(objArrayOop array, int index);
195
196 void update_contents(oop obj);
197
198 class MarkAndPushClosure: public ExtendedOopClosure {
199 private:
200 ParCompactionManager* _compaction_manager;
201 public:
202 MarkAndPushClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
203
204 template <typename T> void do_oop_nv(T* p);
205 virtual void do_oop(oop* p);
206 virtual void do_oop(narrowOop* p);
207
208 // This closure provides its own oop verification code.
209 debug_only(virtual bool should_verify_oops() { return false; })
210 };
211
212 class FollowStackClosure: public VoidClosure {
213 private:
214 ParCompactionManager* _compaction_manager;
215 public:
216 FollowStackClosure(ParCompactionManager* cm) : _compaction_manager(cm) { }
217 virtual void do_void();
218 };
219
220 // The one and only place to start following the classes.
221 // Should only be applied to the ClassLoaderData klasses list.
222 class FollowKlassClosure : public KlassClosure {
223 private:
224 MarkAndPushClosure* _mark_and_push_closure;
225 public:
226 FollowKlassClosure(MarkAndPushClosure* mark_and_push_closure) :
227 _mark_and_push_closure(mark_and_push_closure) { }
228 void do_klass(Klass* klass);
229 };
230 };
231
232 inline ParCompactionManager* ParCompactionManager::manager_array(int index) {
233 assert(_manager_array != NULL, "access of NULL manager_array");
234 assert(index >= 0 && index <= (int)ParallelGCThreads,
235 "out of range manager_array access");
236 return _manager_array[index];
237 }
238
239 bool ParCompactionManager::marking_stacks_empty() const {
240 return _marking_stack.is_empty() && _objarray_stack.is_empty();
241 }
242
243 #endif // SHARE_VM_GC_PARALLEL_PSCOMPACTIONMANAGER_HPP