Mon, 20 Sep 2010 14:38:38 -0700
6984287: Regularize how GC parallel workers are specified.
Summary: Associate number of GC workers with the workgang as opposed to the task.
Reviewed-by: johnc, ysr
1 /*
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25 //
26 // psPromotionManager is used by a single thread to manage object survival
27 // during a scavenge. The promotion manager contains thread local data only.
28 //
29 // NOTE! Be carefull when allocating the stacks on cheap. If you are going
30 // to use a promotion manager in more than one thread, the stacks MUST be
31 // on cheap. This can lead to memory leaks, though, as they are not auto
32 // deallocated.
33 //
34 // FIX ME FIX ME Add a destructor, and don't rely on the user to drain/flush/deallocate!
35 //
37 // Move to some global location
38 #define HAS_BEEN_MOVED 0x1501d01d
39 // End move to some global location
41 class MutableSpace;
42 class PSOldGen;
43 class ParCompactionManager;
45 class PSPromotionManager : public CHeapObj {
46 friend class PSScavenge;
47 friend class PSRefProcTaskExecutor;
48 private:
49 static PSPromotionManager** _manager_array;
50 static OopStarTaskQueueSet* _stack_array_depth;
51 static PSOldGen* _old_gen;
52 static MutableSpace* _young_space;
54 #if TASKQUEUE_STATS
55 size_t _masked_pushes;
56 size_t _masked_steals;
57 size_t _arrays_chunked;
58 size_t _array_chunks_processed;
60 void print_taskqueue_stats(uint i) const;
61 void print_local_stats(uint i) const;
62 static void print_stats();
64 void reset_stats();
65 #endif // TASKQUEUE_STATS
67 PSYoungPromotionLAB _young_lab;
68 PSOldPromotionLAB _old_lab;
69 bool _young_gen_is_full;
70 bool _old_gen_is_full;
72 OopStarTaskQueue _claimed_stack_depth;
73 OverflowTaskQueue<oop> _claimed_stack_breadth;
75 bool _totally_drain;
76 uint _target_stack_size;
78 uint _array_chunk_size;
79 uint _min_array_size_for_chunking;
81 // Accessors
82 static PSOldGen* old_gen() { return _old_gen; }
83 static MutableSpace* young_space() { return _young_space; }
85 inline static PSPromotionManager* manager_array(int index);
86 template <class T> inline void claim_or_forward_internal_depth(T* p);
88 // On the task queues we push reference locations as well as
89 // partially-scanned arrays (in the latter case, we push an oop to
90 // the from-space image of the array and the length on the
91 // from-space image indicates how many entries on the array we still
92 // need to scan; this is basically how ParNew does partial array
93 // scanning too). To be able to distinguish between reference
94 // locations and partially-scanned array oops we simply mask the
95 // latter oops with 0x01. The next three methods do the masking,
96 // unmasking, and checking whether the oop is masked or not. Notice
97 // that the signature of the mask and unmask methods looks a bit
98 // strange, as they accept and return different types (oop and
99 // oop*). This is because of the difference in types between what
100 // the task queue holds (oop*) and oops to partially-scanned arrays
101 // (oop). We do all the necessary casting in the mask / unmask
102 // methods to avoid sprinkling the rest of the code with more casts.
104 // These are added to the taskqueue so PS_CHUNKED_ARRAY_OOP_MASK (or any
105 // future masks) can't conflict with COMPRESSED_OOP_MASK
106 #define PS_CHUNKED_ARRAY_OOP_MASK 0x2
108 bool is_oop_masked(StarTask p) {
109 // If something is marked chunked it's always treated like wide oop*
110 return (((intptr_t)(oop*)p) & PS_CHUNKED_ARRAY_OOP_MASK) ==
111 PS_CHUNKED_ARRAY_OOP_MASK;
112 }
114 oop* mask_chunked_array_oop(oop obj) {
115 assert(!is_oop_masked((oop*) obj), "invariant");
116 oop* ret = (oop*) ((uintptr_t)obj | PS_CHUNKED_ARRAY_OOP_MASK);
117 assert(is_oop_masked(ret), "invariant");
118 return ret;
119 }
121 oop unmask_chunked_array_oop(StarTask p) {
122 assert(is_oop_masked(p), "invariant");
123 assert(!p.is_narrow(), "chunked array oops cannot be narrow");
124 oop *chunk = (oop*)p; // cast p to oop (uses conversion operator)
125 oop ret = oop((oop*)((uintptr_t)chunk & ~PS_CHUNKED_ARRAY_OOP_MASK));
126 assert(!is_oop_masked((oop*) ret), "invariant");
127 return ret;
128 }
130 template <class T> void process_array_chunk_work(oop obj,
131 int start, int end);
132 void process_array_chunk(oop old);
134 template <class T> void push_depth(T* p) {
135 claimed_stack_depth()->push(p);
136 }
138 protected:
139 static OopStarTaskQueueSet* stack_array_depth() { return _stack_array_depth; }
140 public:
141 // Static
142 static void initialize();
144 static void pre_scavenge();
145 static void post_scavenge();
147 static PSPromotionManager* gc_thread_promotion_manager(int index);
148 static PSPromotionManager* vm_thread_promotion_manager();
150 static bool steal_depth(int queue_num, int* seed, StarTask& t) {
151 return stack_array_depth()->steal(queue_num, seed, t);
152 }
154 PSPromotionManager();
156 // Accessors
157 OopStarTaskQueue* claimed_stack_depth() {
158 return &_claimed_stack_depth;
159 }
161 bool young_gen_is_full() { return _young_gen_is_full; }
163 bool old_gen_is_full() { return _old_gen_is_full; }
164 void set_old_gen_is_full(bool state) { _old_gen_is_full = state; }
166 // Promotion methods
167 oop copy_to_survivor_space(oop o);
168 oop oop_promotion_failed(oop obj, markOop obj_mark);
170 void reset();
172 void flush_labs();
173 void drain_stacks(bool totally_drain) {
174 drain_stacks_depth(totally_drain);
175 }
176 public:
177 void drain_stacks_cond_depth() {
178 if (claimed_stack_depth()->size() > _target_stack_size) {
179 drain_stacks_depth(false);
180 }
181 }
182 void drain_stacks_depth(bool totally_drain);
184 bool stacks_empty() {
185 return claimed_stack_depth()->is_empty();
186 }
188 inline void process_popped_location_depth(StarTask p);
190 template <class T> inline void claim_or_forward_depth(T* p);
192 TASKQUEUE_STATS_ONLY(inline void record_steal(StarTask& p);)
193 };