1 /*
   2  * Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   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
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
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  23  */
  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/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 G1OopStarChunkedList;
  41 class G1PLABAllocator;
  42 class G1EvacuationRootClosures;
  43 class HeapRegion;
  44 class outputStream;
  45 
  46 class G1ParScanThreadState : public CHeapObj<mtGC> {
  47   G1CollectedHeap* _g1h;
  48   RefToScanQueue* _refs;
  49   G1RedirtyCardsQueue _rdcq;
  50   G1CardTable* _ct;
  51   G1EvacuationRootClosures* _closures;
  52 
  53   G1PLABAllocator* _plab_allocator;
  54 
  55   AgeTable _age_table;
  56   G1HeapRegionAttr _dest[G1HeapRegionAttr::Num];
  57   // Local tenuring threshold.
  58   uint _tenuring_threshold;
  59   G1ScanEvacuatedObjClosure  _scanner;
  60 
  61   uint _worker_id;
  62 
  63   // Remember the last enqueued card to avoid enqueuing the same card over and over;
  64   // since we only ever scan a card once, this is sufficient.
  65   size_t _last_enqueued_card;
  66 
  67   // Upper and lower threshold to start and end work queue draining.
  68   uint const _stack_trim_upper_threshold;
  69   uint const _stack_trim_lower_threshold;
  70 
  71   Tickspan _trim_ticks;
  72   // Map from young-age-index (0 == not young, 1 is youngest) to
  73   // surviving words. base is what we get back from the malloc call
  74   size_t* _surviving_young_words_base;
  75   // this points into the array, as we use the first few entries for padding
  76   size_t* _surviving_young_words;
  77 
  78   // Indicates whether in the last generation (old) there is no more space
  79   // available for allocation.
  80   bool _old_gen_is_full;
  81 
  82 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
  83 
  84   G1RedirtyCardsQueue& redirty_cards_queue()     { return _rdcq; }
  85   G1CardTable* ct()                              { return _ct; }
  86 
  87   G1HeapRegionAttr dest(G1HeapRegionAttr original) const {
  88     assert(original.is_valid(),
  89            "Original region attr invalid: %s", original.get_type_str());
  90     assert(_dest[original.type()].is_valid_gen(),
  91            "Dest region attr is invalid: %s", _dest[original.type()].get_type_str());
  92     return _dest[original.type()];
  93   }
  94 
  95   size_t _num_optional_regions;
  96   G1OopStarChunkedList* _oops_into_optional_regions;
  97 
  98 public:
  99   G1ParScanThreadState(G1CollectedHeap* g1h,
 100                        G1RedirtyCardsQueueSet* rdcqs,
 101                        uint worker_id,
 102                        size_t young_cset_length,
 103                        size_t optional_cset_length);
 104   virtual ~G1ParScanThreadState();
 105 
 106   void set_ref_discoverer(ReferenceDiscoverer* rd) { _scanner.set_ref_discoverer(rd); }
 107 
 108 #ifdef ASSERT
 109   bool queue_is_empty() const { return _refs->is_empty(); }
 110 
 111   bool verify_ref(narrowOop* ref) const;
 112   bool verify_ref(oop* ref) const;
 113   bool verify_task(StarTask ref) const;
 114 #endif // ASSERT
 115 
 116   template <class T> void do_oop_ext(T* ref);
 117   template <class T> void push_on_queue(T* ref);
 118 
 119   template <class T> void enqueue_card_if_tracked(G1HeapRegionAttr region_attr, T* p, oop o) {
 120     assert(!HeapRegion::is_in_same_region(p, o), "Should have filtered out cross-region references already.");
 121     assert(!_g1h->heap_region_containing(p)->is_young(), "Should have filtered out from-young references already.");
 122 
 123 #ifdef ASSERT
 124     HeapRegion* const hr_obj = _g1h->heap_region_containing((HeapWord*)o);
 125     assert(region_attr.needs_remset_update() == hr_obj->rem_set()->is_tracked(),
 126            "State flag indicating remset tracking disagrees (%s) with actual remembered set (%s) for region %u",
 127            BOOL_TO_STR(region_attr.needs_remset_update()),
 128            BOOL_TO_STR(hr_obj->rem_set()->is_tracked()),
 129            hr_obj->hrm_index());
 130 #endif
 131     if (!region_attr.needs_remset_update()) {
 132       return;
 133     }
 134     size_t card_index = ct()->index_for(p);
 135     // If the card hasn't been added to the buffer, do it.
 136     if (_last_enqueued_card != card_index) {
 137       redirty_cards_queue().enqueue(ct()->byte_for_index(card_index));
 138       _last_enqueued_card = card_index;
 139     }
 140   }
 141 
 142   G1EvacuationRootClosures* closures() { return _closures; }
 143   uint worker_id() { return _worker_id; }
 144 
 145   size_t lab_waste_words() const;
 146   size_t lab_undo_waste_words() const;
 147 
 148   void flush(size_t* surviving_young_words);
 149 
 150 private:
 151   #define G1_PARTIAL_ARRAY_MASK 0x2
 152 
 153   inline bool has_partial_array_mask(oop* ref) const {
 154     return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
 155   }
 156 
 157   // We never encode partial array oops as narrowOop*, so return false immediately.
 158   // This allows the compiler to create optimized code when popping references from
 159   // the work queue.
 160   inline bool has_partial_array_mask(narrowOop* ref) const {
 161     assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
 162     return false;
 163   }
 164 
 165   // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
 166   // We always encode partial arrays as regular oop, to allow the
 167   // specialization for has_partial_array_mask() for narrowOops above.
 168   // This means that unintentional use of this method with narrowOops are caught
 169   // by the compiler.
 170   inline oop* set_partial_array_mask(oop obj) const {
 171     assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
 172     return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
 173   }
 174 
 175   inline oop clear_partial_array_mask(oop* ref) const {
 176     return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
 177   }
 178 
 179   inline void do_oop_partial_array(oop* p);
 180 
 181   // This method is applied to the fields of the objects that have just been copied.
 182   template <class T> inline void do_oop_evac(T* p);
 183 
 184   inline void deal_with_reference(oop* ref_to_scan);
 185   inline void deal_with_reference(narrowOop* ref_to_scan);
 186 
 187   inline void dispatch_reference(StarTask ref);
 188 
 189   // Tries to allocate word_sz in the PLAB of the next "generation" after trying to
 190   // allocate into dest. State is the original (source) cset state for the object
 191   // that is allocated for. Previous_plab_refill_failed indicates whether previously
 192   // a PLAB refill into "state" failed.
 193   // Returns a non-NULL pointer if successful, and updates dest if required.
 194   // Also determines whether we should continue to try to allocate into the various
 195   // generations or just end trying to allocate.
 196   HeapWord* allocate_in_next_plab(G1HeapRegionAttr const region_attr,
 197                                   G1HeapRegionAttr* dest,
 198                                   size_t word_sz,
 199                                   bool previous_plab_refill_failed);
 200 
 201   inline G1HeapRegionAttr next_region_attr(G1HeapRegionAttr const region_attr, markWord const m, uint& age);
 202 
 203   void report_promotion_event(G1HeapRegionAttr const dest_attr,
 204                               oop const old, size_t word_sz, uint age,
 205                               HeapWord * const obj_ptr) const;
 206 
 207   inline bool needs_partial_trimming() const;
 208   inline bool is_partially_trimmed() const;
 209 
 210   inline void trim_queue_to_threshold(uint threshold);
 211 public:
 212   oop copy_to_survivor_space(G1HeapRegionAttr const region_attr, oop const obj, markWord const old_mark);
 213 
 214   void trim_queue();
 215   void trim_queue_partially();
 216 
 217   Tickspan trim_ticks() const;
 218   void reset_trim_ticks();
 219 
 220   inline void steal_and_trim_queue(RefToScanQueueSet *task_queues);
 221 
 222   // An attempt to evacuate "obj" has failed; take necessary steps.
 223   oop handle_evacuation_failure_par(oop obj, markWord m);
 224 
 225   template <typename T>
 226   inline void remember_root_into_optional_region(T* p);
 227   template <typename T>
 228   inline void remember_reference_into_optional_region(T* p);
 229 
 230   inline G1OopStarChunkedList* oops_into_optional_region(const HeapRegion* hr);
 231 };
 232 
 233 class G1ParScanThreadStateSet : public StackObj {
 234   G1CollectedHeap* _g1h;
 235   G1RedirtyCardsQueueSet* _rdcqs;
 236   G1ParScanThreadState** _states;
 237   size_t* _surviving_young_words_total;
 238   size_t _young_cset_length;
 239   size_t _optional_cset_length;
 240   uint _n_workers;
 241   bool _flushed;
 242 
 243  public:
 244   G1ParScanThreadStateSet(G1CollectedHeap* g1h,
 245                           G1RedirtyCardsQueueSet* rdcqs,
 246                           uint n_workers,
 247                           size_t young_cset_length,
 248                           size_t optional_cset_length);
 249   ~G1ParScanThreadStateSet();
 250 
 251   void flush();
 252   void record_unused_optional_region(HeapRegion* hr);
 253 
 254   G1ParScanThreadState* state_for_worker(uint worker_id);
 255 
 256   const size_t* surviving_young_words() const;
 257 
 258  private:
 259   G1ParScanThreadState* new_par_scan_state(uint worker_id, size_t young_cset_length);
 260 };
 261 
 262 #endif // SHARE_GC_G1_G1PARSCANTHREADSTATE_HPP