1 /*
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  6  * under the terms of the GNU General Public License version 2 only, as
  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
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 24 
 25 #ifndef SHARE_GC_G1_G1PARSCANTHREADSTATE_HPP
 26 #define SHARE_GC_G1_G1PARSCANTHREADSTATE_HPP
 27 
 28 #include "gc/g1/g1CollectedHeap.hpp"
 29 #include "gc/g1/g1RedirtyCardsQueue.hpp"
 30 #include "gc/g1/g1OopClosures.hpp"
 31 #include "gc/g1/g1YoungGCAllocationFailureInjector.hpp"
 32 #include "gc/g1/g1_globals.hpp"
 33 #include "gc/shared/ageTable.hpp"
 34 #include "gc/shared/copyFailedInfo.hpp"
 35 #include "gc/shared/partialArrayTaskStepper.hpp"
 36 #include "gc/shared/preservedMarks.hpp"
 37 #include "gc/shared/stringdedup/stringDedup.hpp"
 38 #include "gc/shared/taskqueue.hpp"
 39 #include "memory/allocation.hpp"
 40 #include "oops/oop.hpp"
 41 #include "utilities/ticks.hpp"
 42 
 43 class G1CardTable;
 44 class G1CollectionSet;
 45 class G1EvacFailureRegions;
 46 class G1EvacuationRootClosures;
 47 class G1OopStarChunkedList;
 48 class G1PLABAllocator;
 49 class HeapRegion;
 50 class PreservedMarks;
 51 class PreservedMarksSet;
 52 class outputStream;
 53 
 54 class G1ParScanThreadState : public CHeapObj<mtGC> {
 55   G1CollectedHeap* _g1h;
 56   G1ScannerTasksQueue* _task_queue;
 57   G1RedirtyCardsLocalQueueSet _rdc_local_qset;
 58   G1CardTable* _ct;
 59   G1EvacuationRootClosures* _closures;
 60 
 61   G1PLABAllocator* _plab_allocator;
 62 
 63   AgeTable _age_table;
 64   // Local tenuring threshold.
 65   uint _tenuring_threshold;
 66   G1ScanEvacuatedObjClosure _scanner;
 67 
 68   uint _worker_id;
 69 
 70   // Remember the last enqueued card to avoid enqueuing the same card over and over;
 71   // since we only ever scan a card once, this is sufficient.
 72   size_t _last_enqueued_card;
 73 
 74   // Upper and lower threshold to start and end work queue draining.
 75   uint const _stack_trim_upper_threshold;
 76   uint const _stack_trim_lower_threshold;
 77 
 78   Tickspan _trim_ticks;
 79   // Map from young-age-index (0 == not young, 1 is youngest) to
 80   // surviving words. base is what we get back from the malloc call
 81   size_t* _surviving_young_words_base;
 82   // this points into the array, as we use the first few entries for padding
 83   size_t* _surviving_young_words;
 84   // Number of elements in the array above.
 85   size_t _surviving_words_length;
 86   // Indicates whether in the last generation (old) there is no more space
 87   // available for allocation.
 88   bool _old_gen_is_full;
 89   // Size (in elements) of a partial objArray task chunk.
 90   int _partial_objarray_chunk_size;
 91   PartialArrayTaskStepper _partial_array_stepper;
 92   StringDedup::Requests _string_dedup_requests;
 93 
 94   G1CardTable* ct() { return _ct; }
 95 
 96   // Maximum number of optional regions at start of gc.
 97   size_t _max_num_optional_regions;
 98   G1OopStarChunkedList* _oops_into_optional_regions;
 99 
100   G1NUMA* _numa;
101   // Records how many object allocations happened at each node during copy to survivor.
102   // Only starts recording when log of gc+heap+numa is enabled and its data is
103   // transferred when flushed.
104   size_t* _obj_alloc_stat;
105 
106   // Per-thread evacuation failure data structures.
107   ALLOCATION_FAILURE_INJECTOR_ONLY(size_t _allocation_failure_inject_counter;)
108 
109   PreservedMarks* _preserved_marks;
110   EvacuationFailedInfo _evacuation_failed_info;
111   G1EvacFailureRegions* _evac_failure_regions;
112   // Number of additional cards into evacuation failed regions enqueued into
113   // the local DCQS. This is an approximation, as cards that would be added later
114   // outside of evacuation failure will not be subtracted again.
115   size_t _evac_failure_enqueued_cards;
116 
117   // Enqueue the card if not already in the set; this is a best-effort attempt on
118   // detecting duplicates.
119   template <class T> bool enqueue_if_new(T* p);
120   // Enqueue the card of p into the (evacuation failed) region.
121   template <class T> void enqueue_card_into_evac_fail_region(T* p, oop obj);
122 
123   bool inject_allocation_failure(uint region_idx) ALLOCATION_FAILURE_INJECTOR_RETURN_( return false; );
124 
125 public:
126   G1ParScanThreadState(G1CollectedHeap* g1h,
127                        G1RedirtyCardsQueueSet* rdcqs,
128                        PreservedMarks* preserved_marks,
129                        uint worker_id,
130                        uint num_workers,
131                        G1CollectionSet* collection_set,
132                        G1EvacFailureRegions* evac_failure_regions);
133   virtual ~G1ParScanThreadState();
134 
135   void set_ref_discoverer(ReferenceDiscoverer* rd) { _scanner.set_ref_discoverer(rd); }
136 
137 #ifdef ASSERT
138   bool queue_is_empty() const { return _task_queue->is_empty(); }
139 #endif
140 
141   void verify_task(narrowOop* task) const NOT_DEBUG_RETURN;
142   void verify_task(oop* task) const NOT_DEBUG_RETURN;
143   void verify_task(PartialArrayScanTask task) const NOT_DEBUG_RETURN;
144   void verify_task(ScannerTask task) const NOT_DEBUG_RETURN;
145 
146   void push_on_queue(ScannerTask task);
147 
148   // Apply the post barrier to the given reference field. Enqueues the card of p
149   // if the barrier does not filter out the reference for some reason (e.g.
150   // p and q are in the same region, p is in survivor, p is in collection set)
151   // To be called during GC if nothing particular about p and obj are known.
152   template <class T> void write_ref_field_post(T* p, oop obj);
153 
154   // Enqueue the card if the reference's target region's remembered set is tracked.
155   // Assumes that a significant amount of pre-filtering (like done by
156   // write_ref_field_post() above) has already been performed.
157   template <class T> void enqueue_card_if_tracked(G1HeapRegionAttr region_attr, T* p, oop o);
158 
159   G1EvacuationRootClosures* closures() { return _closures; }
160   uint worker_id() { return _worker_id; }
161 
162   size_t lab_waste_words() const;
163   size_t lab_undo_waste_words() const;
164 
165   size_t evac_failure_enqueued_cards() const;
166 
167   // Pass locally gathered statistics to global state. Returns the total number of
168   // HeapWords copied.
169   size_t flush_stats(size_t* surviving_young_words, uint num_workers);
170 
171 private:
172   void do_partial_array(PartialArrayScanTask task);
173   void start_partial_objarray(G1HeapRegionAttr dest_dir, oop from, oop to);
174 
175   HeapWord* allocate_copy_slow(G1HeapRegionAttr* dest_attr,
176                                oop old,
177                                size_t word_sz,
178                                uint age,
179                                uint node_index);
180 
181   void undo_allocation(G1HeapRegionAttr dest_addr,
182                        HeapWord* obj_ptr,
183                        size_t word_sz,
184                        uint node_index);
185 
186   void update_bot_after_copying(oop obj, size_t word_sz);
187 
188   oop do_copy_to_survivor_space(G1HeapRegionAttr region_attr,
189                                 oop obj,
190                                 markWord old_mark);
191 
192   // This method is applied to the fields of the objects that have just been copied.
193   template <class T> void do_oop_evac(T* p);
194 
195   void dispatch_task(ScannerTask task);
196 
197   // Tries to allocate word_sz in the PLAB of the next "generation" after trying to
198   // allocate into dest. Previous_plab_refill_failed indicates whether previous
199   // PLAB refill for the original (source) object failed.
200   // Returns a non-null pointer if successful, and updates dest if required.
201   // Also determines whether we should continue to try to allocate into the various
202   // generations or just end trying to allocate.
203   HeapWord* allocate_in_next_plab(G1HeapRegionAttr* dest,
204                                   size_t word_sz,
205                                   bool previous_plab_refill_failed,
206                                   uint node_index);
207 
208   inline G1HeapRegionAttr next_region_attr(G1HeapRegionAttr const region_attr, markWord const m, uint& age);
209 
210   void report_promotion_event(G1HeapRegionAttr const dest_attr,
211                               oop const old, size_t word_sz, uint age,
212                               HeapWord * const obj_ptr, uint node_index) const;
213 
214   void trim_queue_to_threshold(uint threshold);
215 
216   inline bool needs_partial_trimming() const;
217 
218   // NUMA statistics related methods.
219   void initialize_numa_stats();
220   void flush_numa_stats();
221   inline void update_numa_stats(uint node_index);
222 
223 public:
224   oop copy_to_survivor_space(G1HeapRegionAttr region_attr, oop obj, markWord old_mark);
225 
226   inline void trim_queue();
227   inline void trim_queue_partially();
228   void steal_and_trim_queue(G1ScannerTasksQueueSet *task_queues);
229 
230   Tickspan trim_ticks() const;
231   void reset_trim_ticks();
232 
233   // An attempt to evacuate "obj" has failed; take necessary steps.
234   oop handle_evacuation_failure_par(oop obj, markWord m, size_t word_sz, bool cause_pinned);
235 
236   template <typename T>
237   inline void remember_root_into_optional_region(T* p);
238   template <typename T>
239   inline void remember_reference_into_optional_region(T* p);
240 
241   inline G1OopStarChunkedList* oops_into_optional_region(const HeapRegion* hr);
242 };
243 
244 class G1ParScanThreadStateSet : public StackObj {
245   G1CollectedHeap* _g1h;
246   G1CollectionSet* _collection_set;
247   G1RedirtyCardsQueueSet _rdcqs;
248   PreservedMarksSet _preserved_marks_set;
249   G1ParScanThreadState** _states;
250   size_t* _surviving_young_words_total;
251   uint _num_workers;
252   bool _flushed;
253   G1EvacFailureRegions* _evac_failure_regions;
254 
255  public:
256   G1ParScanThreadStateSet(G1CollectedHeap* g1h,
257                           uint num_workers,
258                           G1CollectionSet* collection_set,
259                           G1EvacFailureRegions* evac_failure_regions);
260   ~G1ParScanThreadStateSet();
261 
262   G1RedirtyCardsQueueSet* rdcqs() { return &_rdcqs; }
263   PreservedMarksSet* preserved_marks_set() { return &_preserved_marks_set; }
264 
265   void flush_stats();
266   void record_unused_optional_region(HeapRegion* hr);
267 
268   G1ParScanThreadState* state_for_worker(uint worker_id);
269 
270   const size_t* surviving_young_words() const;
271 };
272 
273 #endif // SHARE_GC_G1_G1PARSCANTHREADSTATE_HPP