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24 
25 #ifndef SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP
26 #define SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP
27 
28 #include "gc/g1/dirtyCardQueue.hpp"
29 #include "gc/g1/g1CardTable.hpp"
30 #include "gc/g1/g1CollectedHeap.hpp"
31 #include "gc/g1/g1OopClosures.hpp"
32 #include "gc/g1/g1Policy.hpp"
33 #include "gc/g1/g1RemSet.hpp"
34 #include "gc/g1/heapRegionRemSet.hpp"
35 #include "gc/shared/ageTable.hpp"
36 #include "memory/allocation.hpp"
37 #include "oops/oop.hpp"
38 #include "utilities/ticks.hpp"
39 
40 class G1PLABAllocator;
41 class G1EvacuationRootClosures;
42 class HeapRegion;
43 class outputStream;
44 
45 class G1ParScanThreadState : public CHeapObj<mtGC> {
46   G1CollectedHeap* _g1h;
47   RefToScanQueue*  _refs;
48   DirtyCardQueue   _dcq;
49   G1CardTable*     _ct;
50   G1EvacuationRootClosures* _closures;
51 
52   G1PLABAllocator*  _plab_allocator;
53 
54   AgeTable          _age_table;
55   InCSetState       _dest[InCSetState::Num];
56   // Local tenuring threshold.
57   uint              _tenuring_threshold;
58   G1ScanEvacuatedObjClosure  _scanner;
59 
60   int  _hash_seed;
61   uint _worker_id;
62 
63   // Upper and lower threshold to start and end work queue draining.
64   uint const _stack_trim_upper_threshold;
65   uint const _stack_trim_lower_threshold;
66 
67   Tickspan _trim_ticks;
68   // Map from young-age-index (0 == not young, 1 is youngest) to
69   // surviving words. base is what we get back from the malloc call
70   size_t* _surviving_young_words_base;
71   // this points into the array, as we use the first few entries for padding
72   size_t* _surviving_young_words;
73 
74   // Indicates whether in the last generation (old) there is no more space
75   // available for allocation.
76   bool _old_gen_is_full;
77 
78 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
79 
dirty_card_queue()80   DirtyCardQueue& dirty_card_queue()             { return _dcq;  }
ct()81   G1CardTable* ct()                              { return _ct; }
82 
dest(InCSetState original) const83   InCSetState dest(InCSetState original) const {
84     assert(original.is_valid(),
85            "Original state invalid: " CSETSTATE_FORMAT, original.value());
86     assert(_dest[original.value()].is_valid_gen(),
87            "Dest state is invalid: " CSETSTATE_FORMAT, _dest[original.value()].value());
88     return _dest[original.value()];
89   }
90 
91 public:
92   G1ParScanThreadState(G1CollectedHeap* g1h, uint worker_id, size_t young_cset_length);
93   virtual ~G1ParScanThreadState();
94 
set_ref_discoverer(ReferenceDiscoverer * rd)95   void set_ref_discoverer(ReferenceDiscoverer* rd) { _scanner.set_ref_discoverer(rd); }
96 
97 #ifdef ASSERT
queue_is_empty() const98   bool queue_is_empty() const { return _refs->is_empty(); }
99 
100   bool verify_ref(narrowOop* ref) const;
101   bool verify_ref(oop* ref) const;
102   bool verify_task(StarTask ref) const;
103 #endif // ASSERT
104 
105   template <class T> void do_oop_ext(T* ref);
106   template <class T> void push_on_queue(T* ref);
107 
update_rs(HeapRegion * from,T * p,oop o)108   template <class T> void update_rs(HeapRegion* from, T* p, oop o) {
109     assert(!HeapRegion::is_in_same_region(p, o), "Caller should have filtered out cross-region references already.");
110     // If the field originates from the to-space, we don't need to include it
111     // in the remembered set updates. Also, if we are not tracking the remembered
112     // set in the destination region, do not bother either.
113     if (!from->is_young() && _g1h->heap_region_containing((HeapWord*)o)->rem_set()->is_tracked()) {
114       size_t card_index = ct()->index_for(p);
115       // If the card hasn't been added to the buffer, do it.
116       if (ct()->mark_card_deferred(card_index)) {
117         dirty_card_queue().enqueue((jbyte*)ct()->byte_for_index(card_index));
118       }
119     }
120   }
121 
closures()122   G1EvacuationRootClosures* closures() { return _closures; }
worker_id()123   uint worker_id() { return _worker_id; }
124 
125   // Returns the current amount of waste due to alignment or not being able to fit
126   // objects within LABs and the undo waste.
127   virtual void waste(size_t& wasted, size_t& undo_wasted);
128 
surviving_young_words()129   size_t* surviving_young_words() {
130     // We add one to hide entry 0 which accumulates surviving words for
131     // age -1 regions (i.e. non-young ones)
132     return _surviving_young_words + 1;
133   }
134 
135   void flush(size_t* surviving_young_words);
136 
137 private:
138   #define G1_PARTIAL_ARRAY_MASK 0x2
139 
has_partial_array_mask(oop * ref) const140   inline bool has_partial_array_mask(oop* ref) const {
141     return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
142   }
143 
144   // We never encode partial array oops as narrowOop*, so return false immediately.
145   // This allows the compiler to create optimized code when popping references from
146   // the work queue.
has_partial_array_mask(narrowOop * ref) const147   inline bool has_partial_array_mask(narrowOop* ref) const {
148     assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
149     return false;
150   }
151 
152   // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
153   // We always encode partial arrays as regular oop, to allow the
154   // specialization for has_partial_array_mask() for narrowOops above.
155   // This means that unintentional use of this method with narrowOops are caught
156   // by the compiler.
set_partial_array_mask(oop obj) const157   inline oop* set_partial_array_mask(oop obj) const {
158     assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
159     return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
160   }
161 
clear_partial_array_mask(oop * ref) const162   inline oop clear_partial_array_mask(oop* ref) const {
163     return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
164   }
165 
166   inline void do_oop_partial_array(oop* p);
167 
168   // This method is applied to the fields of the objects that have just been copied.
169   template <class T> inline void do_oop_evac(T* p);
170 
171   inline void deal_with_reference(oop* ref_to_scan);
172   inline void deal_with_reference(narrowOop* ref_to_scan);
173 
174   inline void dispatch_reference(StarTask ref);
175 
176   // Tries to allocate word_sz in the PLAB of the next "generation" after trying to
177   // allocate into dest. State is the original (source) cset state for the object
178   // that is allocated for. Previous_plab_refill_failed indicates whether previously
179   // a PLAB refill into "state" failed.
180   // Returns a non-NULL pointer if successful, and updates dest if required.
181   // Also determines whether we should continue to try to allocate into the various
182   // generations or just end trying to allocate.
183   HeapWord* allocate_in_next_plab(InCSetState const state,
184                                   InCSetState* dest,
185                                   size_t word_sz,
186                                   bool previous_plab_refill_failed);
187 
188   inline InCSetState next_state(InCSetState const state, markOop const m, uint& age);
189 
190   void report_promotion_event(InCSetState const dest_state,
191                               oop const old, size_t word_sz, uint age,
192                               HeapWord * const obj_ptr) const;
193 
194   inline bool needs_partial_trimming() const;
195   inline bool is_partially_trimmed() const;
196 
197   inline void trim_queue_to_threshold(uint threshold);
198 public:
199   oop copy_to_survivor_space(InCSetState const state, oop const obj, markOop const old_mark);
200 
201   void trim_queue();
202   void trim_queue_partially();
203 
204   Tickspan trim_ticks() const;
205   void reset_trim_ticks();
206 
207   inline void steal_and_trim_queue(RefToScanQueueSet *task_queues);
208 
209   // An attempt to evacuate "obj" has failed; take necessary steps.
210   oop handle_evacuation_failure_par(oop obj, markOop m);
211 };
212 
213 class G1ParScanThreadStateSet : public StackObj {
214   G1CollectedHeap* _g1h;
215   G1ParScanThreadState** _states;
216   size_t* _surviving_young_words_total;
217   size_t _young_cset_length;
218   uint _n_workers;
219   bool _flushed;
220 
221  public:
222   G1ParScanThreadStateSet(G1CollectedHeap* g1h, uint n_workers, size_t young_cset_length);
223   ~G1ParScanThreadStateSet();
224 
225   void flush();
226 
227   G1ParScanThreadState* state_for_worker(uint worker_id);
228 
229   const size_t* surviving_young_words() const;
230 
231  private:
232   G1ParScanThreadState* new_par_scan_state(uint worker_id, size_t young_cset_length);
233 };
234 
235 #endif // SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP
236