Tue, 28 Sep 2010 15:56:15 -0700
6423256: GC stacks should use a better data structure
6942771: SEGV in ParScanThreadState::take_from_overflow_stack
Reviewed-by: apetrusenko, ysr, pbk
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.
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7 * published by the Free Software Foundation.
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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 *
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23 */
25 // Move to some global location
26 #define HAS_BEEN_MOVED 0x1501d01d
27 // End move to some global location
30 class MutableSpace;
31 class PSOldGen;
32 class ParCompactionManager;
33 class ObjectStartArray;
34 class ParallelCompactData;
35 class ParMarkBitMap;
37 class ParCompactionManager : public CHeapObj {
38 friend class ParallelTaskTerminator;
39 friend class ParMarkBitMap;
40 friend class PSParallelCompact;
41 friend class StealRegionCompactionTask;
42 friend class UpdateAndFillClosure;
43 friend class RefProcTaskExecutor;
45 public:
47 // ------------------------ Don't putback if not needed
48 // Actions that the compaction manager should take.
49 enum Action {
50 Update,
51 Copy,
52 UpdateAndCopy,
53 CopyAndUpdate,
54 VerifyUpdate,
55 ResetObjects,
56 NotValid
57 };
58 // ------------------------ End don't putback if not needed
60 private:
61 // 32-bit: 4K * 8 = 32KiB; 64-bit: 8K * 16 = 128KiB
62 #define QUEUE_SIZE (1 << NOT_LP64(12) LP64_ONLY(13))
63 typedef OverflowTaskQueue<ObjArrayTask, QUEUE_SIZE> ObjArrayTaskQueue;
64 typedef GenericTaskQueueSet<ObjArrayTaskQueue> ObjArrayTaskQueueSet;
65 #undef QUEUE_SIZE
67 static ParCompactionManager** _manager_array;
68 static OopTaskQueueSet* _stack_array;
69 static ObjArrayTaskQueueSet* _objarray_queues;
70 static ObjectStartArray* _start_array;
71 static RegionTaskQueueSet* _region_array;
72 static PSOldGen* _old_gen;
74 private:
75 OverflowTaskQueue<oop> _marking_stack;
76 ObjArrayTaskQueue _objarray_stack;
78 // Is there a way to reuse the _marking_stack for the
79 // saving empty regions? For now just create a different
80 // type of TaskQueue.
81 RegionTaskQueue _region_stack;
83 Stack<Klass*> _revisit_klass_stack;
84 Stack<DataLayout*> _revisit_mdo_stack;
86 static ParMarkBitMap* _mark_bitmap;
88 Action _action;
90 static PSOldGen* old_gen() { return _old_gen; }
91 static ObjectStartArray* start_array() { return _start_array; }
92 static OopTaskQueueSet* stack_array() { return _stack_array; }
94 static void initialize(ParMarkBitMap* mbm);
96 protected:
97 // Array of tasks. Needed by the ParallelTaskTerminator.
98 static RegionTaskQueueSet* region_array() { return _region_array; }
99 OverflowTaskQueue<oop>* marking_stack() { return &_marking_stack; }
100 RegionTaskQueue* region_stack() { return &_region_stack; }
102 // Pushes onto the marking stack. If the marking stack is full,
103 // pushes onto the overflow stack.
104 void stack_push(oop obj);
105 // Do not implement an equivalent stack_pop. Deal with the
106 // marking stack and overflow stack directly.
108 public:
109 Action action() { return _action; }
110 void set_action(Action v) { _action = v; }
112 inline static ParCompactionManager* manager_array(int index);
114 ParCompactionManager();
116 ParMarkBitMap* mark_bitmap() { return _mark_bitmap; }
118 // Take actions in preparation for a compaction.
119 static void reset();
121 // void drain_stacks();
123 bool should_update();
124 bool should_copy();
125 bool should_verify_only();
126 bool should_reset_only();
128 Stack<Klass*>* revisit_klass_stack() { return &_revisit_klass_stack; }
129 Stack<DataLayout*>* revisit_mdo_stack() { return &_revisit_mdo_stack; }
131 // Save for later processing. Must not fail.
132 inline void push(oop obj) { _marking_stack.push(obj); }
133 inline void push_objarray(oop objarray, size_t index);
134 inline void push_region(size_t index);
136 // Access function for compaction managers
137 static ParCompactionManager* gc_thread_compaction_manager(int index);
139 static bool steal(int queue_num, int* seed, oop& t) {
140 return stack_array()->steal(queue_num, seed, t);
141 }
143 static bool steal_objarray(int queue_num, int* seed, ObjArrayTask& t) {
144 return _objarray_queues->steal(queue_num, seed, t);
145 }
147 static bool steal(int queue_num, int* seed, size_t& region) {
148 return region_array()->steal(queue_num, seed, region);
149 }
151 // Process tasks remaining on any marking stack
152 void follow_marking_stacks();
153 inline bool marking_stacks_empty() const;
155 // Process tasks remaining on any stack
156 void drain_region_stacks();
158 };
160 inline ParCompactionManager* ParCompactionManager::manager_array(int index) {
161 assert(_manager_array != NULL, "access of NULL manager_array");
162 assert(index >= 0 && index <= (int)ParallelGCThreads,
163 "out of range manager_array access");
164 return _manager_array[index];
165 }
167 bool ParCompactionManager::marking_stacks_empty() const {
168 return _marking_stack.is_empty() && _objarray_stack.is_empty();
169 }