1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  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
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 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 24 
 25 #ifndef SHARE_GC_G1_G1PARSCANTHREADSTATE_HPP
 26 #define SHARE_GC_G1_G1PARSCANTHREADSTATE_HPP
 27 
 28 #include "gc/g1/g1CardTable.hpp"
 29 #include "gc/g1/g1CollectedHeap.hpp"
 30 #include "gc/g1/g1RedirtyCardsQueue.hpp"
 31 #include "gc/g1/g1OopClosures.hpp"
 32 #include "gc/g1/g1RemSet.hpp"
 33 #include "gc/g1/heapRegionRemSet.hpp"
 34 #include "gc/shared/ageTable.hpp"
 35 #include "gc/shared/partialArrayTaskStepper.hpp"
 36 #include "gc/shared/stringdedup/stringDedup.hpp"
 37 #include "gc/shared/taskqueue.hpp"
 38 #include "memory/allocation.hpp"
 39 #include "oops/oop.hpp"
 40 #include "utilities/ticks.hpp"
 41 
 42 class G1OopStarChunkedList;
 43 class G1PLABAllocator;
 44 class G1EvacuationRootClosures;
 45 class HeapRegion;
 46 class outputStream;
 47 
 48 class G1ParScanThreadState : public CHeapObj<mtGC> {
 49   G1CollectedHeap* _g1h;
 50   G1ScannerTasksQueue* _task_queue;
 51   G1RedirtyCardsLocalQueueSet _rdc_local_qset;
 52   G1CardTable* _ct;
 53   G1EvacuationRootClosures* _closures;
 54 
 55   G1PLABAllocator* _plab_allocator;
 56 
 57   AgeTable _age_table;
 58   G1HeapRegionAttr _dest[G1HeapRegionAttr::Num];
 59   // Local tenuring threshold.
 60   uint _tenuring_threshold;
 61   G1ScanEvacuatedObjClosure  _scanner;
 62 
 63   uint _worker_id;
 64 
 65   // Remember the last enqueued card to avoid enqueuing the same card over and over;
 66   // since we only ever scan a card once, this is sufficient.
 67   size_t _last_enqueued_card;
 68 
 69   // Upper and lower threshold to start and end work queue draining.
 70   uint const _stack_trim_upper_threshold;
 71   uint const _stack_trim_lower_threshold;
 72 
 73   Tickspan _trim_ticks;
 74   // Map from young-age-index (0 == not young, 1 is youngest) to
 75   // surviving words. base is what we get back from the malloc call
 76   size_t* _surviving_young_words_base;
 77   // this points into the array, as we use the first few entries for padding
 78   size_t* _surviving_young_words;
 79   // Number of elements in the array above.
 80   size_t _surviving_words_length;
 81   // Indicates whether in the last generation (old) there is no more space
 82   // available for allocation.
 83   bool _old_gen_is_full;
 84   // Size (in elements) of a partial objArray task chunk.
 85   int _partial_objarray_chunk_size;
 86   PartialArrayTaskStepper _partial_array_stepper;
 87   StringDedup::Requests _string_dedup_requests;
 88 
 89   G1CardTable* ct() { return _ct; }
 90 
 91   G1HeapRegionAttr dest(G1HeapRegionAttr original) const {
 92     assert(original.is_valid(),
 93            "Original region attr invalid: %s", original.get_type_str());
 94     assert(_dest[original.type()].is_valid_gen(),
 95            "Dest region attr is invalid: %s", _dest[original.type()].get_type_str());
 96     return _dest[original.type()];
 97   }
 98 
 99   size_t _num_optional_regions;
100   G1OopStarChunkedList* _oops_into_optional_regions;
101 
102   G1NUMA* _numa;
103 
104   // Records how many object allocations happened at each node during copy to survivor.
105   // Only starts recording when log of gc+heap+numa is enabled and its data is
106   // transferred when flushed.
107   size_t* _obj_alloc_stat;
108 
109 public:
110   G1ParScanThreadState(G1CollectedHeap* g1h,
111                        G1RedirtyCardsQueueSet* rdcqs,
112                        uint worker_id,
113                        uint n_workers,
114                        size_t young_cset_length,
115                        size_t optional_cset_length);
116   virtual ~G1ParScanThreadState();
117 
118   void set_ref_discoverer(ReferenceDiscoverer* rd) { _scanner.set_ref_discoverer(rd); }
119 
120 #ifdef ASSERT
121   bool queue_is_empty() const { return _task_queue->is_empty(); }
122 #endif
123 
124   void verify_task(narrowOop* task) const NOT_DEBUG_RETURN;
125   void verify_task(oop* task) const NOT_DEBUG_RETURN;
126   void verify_task(PartialArrayScanTask task) const NOT_DEBUG_RETURN;
127   void verify_task(ScannerTask task) const NOT_DEBUG_RETURN;
128 
129   void push_on_queue(ScannerTask task);
130 
131   // Apply the post barrier to the given reference field. Enqueues the card of p
132   // if the barrier does not filter out the reference for some reason (e.g.
133   // p and q are in the same region, p is in survivor, p is in collection set)
134   // To be called during GC if nothing particular about p and obj are known.
135   template <class T> void write_ref_field_post(T* p, oop obj);
136 
137   template <class T> void enqueue_card_if_tracked(G1HeapRegionAttr region_attr, T* p, oop o) {
138     assert(!HeapRegion::is_in_same_region(p, o), "Should have filtered out cross-region references already.");
139     assert(!_g1h->heap_region_containing(p)->is_young(), "Should have filtered out from-young references already.");
140 
141 #ifdef ASSERT
142     HeapRegion* const hr_obj = _g1h->heap_region_containing(o);
143     assert(region_attr.needs_remset_update() == hr_obj->rem_set()->is_tracked(),
144            "State flag indicating remset tracking disagrees (%s) with actual remembered set (%s) for region %u",
145            BOOL_TO_STR(region_attr.needs_remset_update()),
146            BOOL_TO_STR(hr_obj->rem_set()->is_tracked()),
147            hr_obj->hrm_index());
148 #endif
149     if (!region_attr.needs_remset_update()) {
150       return;
151     }
152     size_t card_index = ct()->index_for(p);
153     // If the card hasn't been added to the buffer, do it.
154     if (_last_enqueued_card != card_index) {
155       _rdc_local_qset.enqueue(ct()->byte_for_index(card_index));
156       _last_enqueued_card = card_index;
157     }
158   }
159 
160   G1EvacuationRootClosures* closures() { return _closures; }
161   uint worker_id() { return _worker_id; }
162 
163   size_t lab_waste_words() const;
164   size_t lab_undo_waste_words() const;
165 
166   // Pass locally gathered statistics to global state. Returns the total number of
167   // HeapWords copied.
168   size_t flush(size_t* surviving_young_words);
169 
170 private:
171   void do_partial_array(PartialArrayScanTask task);
172   void start_partial_objarray(G1HeapRegionAttr dest_dir, oop from, oop to);
173 
174   HeapWord* allocate_copy_slow(G1HeapRegionAttr* dest_attr,
175                                Klass* klass,
176                                size_t word_sz,
177                                uint age,
178                                uint node_index);
179 
180   void undo_allocation(G1HeapRegionAttr dest_addr,
181                        HeapWord* obj_ptr,
182                        size_t word_sz,
183                        uint node_index);
184 
185   oop do_copy_to_survivor_space(G1HeapRegionAttr region_attr,
186                                 oop obj,
187                                 markWord old_mark);
188 
189   // This method is applied to the fields of the objects that have just been copied.
190   template <class T> void do_oop_evac(T* p);
191 
192   void dispatch_task(ScannerTask task);
193 
194   // Tries to allocate word_sz in the PLAB of the next "generation" after trying to
195   // allocate into dest. Previous_plab_refill_failed indicates whether previous
196   // PLAB refill for the original (source) object failed.
197   // Returns a non-NULL pointer if successful, and updates dest if required.
198   // Also determines whether we should continue to try to allocate into the various
199   // generations or just end trying to allocate.
200   HeapWord* allocate_in_next_plab(G1HeapRegionAttr* dest,
201                                   size_t word_sz,
202                                   bool previous_plab_refill_failed,
203                                   uint node_index);
204 
205   inline G1HeapRegionAttr next_region_attr(G1HeapRegionAttr const region_attr, markWord const m, uint& age);
206 
207   void report_promotion_event(G1HeapRegionAttr const dest_attr,
208                               Klass* klass, size_t word_sz, uint age,
209                               HeapWord * const obj_ptr, uint node_index) const;
210 
211   void trim_queue_to_threshold(uint threshold);
212 
213   inline bool needs_partial_trimming() const;
214 
215   // NUMA statistics related methods.
216   void initialize_numa_stats();
217   void flush_numa_stats();
218   inline void update_numa_stats(uint node_index);
219 
220 public:
221   oop copy_to_survivor_space(G1HeapRegionAttr region_attr, oop obj, markWord old_mark);
222 
223   inline void trim_queue();
224   inline void trim_queue_partially();
225   void steal_and_trim_queue(G1ScannerTasksQueueSet *task_queues);
226 
227   Tickspan trim_ticks() const;
228   void reset_trim_ticks();
229 
230   // An attempt to evacuate "obj" has failed; take necessary steps.
231   oop handle_evacuation_failure_par(oop obj, markWord m);
232 
233   template <typename T>
234   inline void remember_root_into_optional_region(T* p);
235   template <typename T>
236   inline void remember_reference_into_optional_region(T* p);
237 
238   inline G1OopStarChunkedList* oops_into_optional_region(const HeapRegion* hr);
239 };
240 
241 class G1ParScanThreadStateSet : public StackObj {
242   G1CollectedHeap* _g1h;
243   G1RedirtyCardsQueueSet* _rdcqs;
244   G1ParScanThreadState** _states;
245   size_t* _surviving_young_words_total;
246   size_t _young_cset_length;
247   size_t _optional_cset_length;
248   uint _n_workers;
249   bool _flushed;
250 
251  public:
252   G1ParScanThreadStateSet(G1CollectedHeap* g1h,
253                           G1RedirtyCardsQueueSet* rdcqs,
254                           uint n_workers,
255                           size_t young_cset_length,
256                           size_t optional_cset_length);
257   ~G1ParScanThreadStateSet();
258 
259   void flush();
260   void record_unused_optional_region(HeapRegion* hr);
261 
262   G1ParScanThreadState* state_for_worker(uint worker_id);
263 
264   const size_t* surviving_young_words() const;
265 };
266 
267 #endif // SHARE_GC_G1_G1PARSCANTHREADSTATE_HPP