1 /*
   2  * Copyright (c) 2014, 2015, 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.
  22  *
  23  */
  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/g1CollectedHeap.hpp"
  30 #include "gc/g1/g1CollectorPolicy.hpp"
  31 #include "gc/g1/g1OopClosures.hpp"
  32 #include "gc/g1/g1RemSet.hpp"
  33 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
  34 #include "gc/shared/ageTable.hpp"
  35 #include "memory/allocation.hpp"
  36 #include "oops/oop.hpp"
  37 
  38 class G1PLABAllocator;
  39 class HeapRegion;
  40 class outputStream;
  41 
  42 class G1ParScanThreadState : public CHeapObj<mtGC> {
  43  private:
  44   G1CollectedHeap* _g1h;
  45   RefToScanQueue*  _refs;
  46   DirtyCardQueue   _dcq;
  47   G1SATBCardTableModRefBS* _ct_bs;
  48   G1RemSet*         _g1_rem;
  49 
  50   G1PLABAllocator*  _plab_allocator;
  51 
  52   ageTable          _age_table;
  53   InCSetState       _dest[InCSetState::Num];
  54   // Local tenuring threshold.
  55   uint              _tenuring_threshold;
  56   G1ParScanClosure  _scanner;
  57 
  58   int  _hash_seed;
  59   uint _worker_id;
  60 
  61   // Map from young-age-index (0 == not young, 1 is youngest) to
  62   // surviving words. base is what we get back from the malloc call
  63   size_t* _surviving_young_words_base;
  64   // this points into the array, as we use the first few entries for padding
  65   size_t* _surviving_young_words;
  66 
  67   // Indicates whether in the last generation (old) there is no more space
  68   // available for allocation.
  69   bool _old_gen_is_full;
  70 
  71 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
  72 
  73   DirtyCardQueue& dirty_card_queue()             { return _dcq;  }
  74   G1SATBCardTableModRefBS* ctbs()                { return _ct_bs; }
  75 
  76   InCSetState dest(InCSetState original) const {
  77     assert(original.is_valid(),
  78            "Original state invalid: " CSETSTATE_FORMAT, original.value());
  79     assert(_dest[original.value()].is_valid_gen(),
  80            "Dest state is invalid: " CSETSTATE_FORMAT, _dest[original.value()].value());
  81     return _dest[original.value()];
  82   }
  83 
  84  public:
  85   G1ParScanThreadState(G1CollectedHeap* g1h, uint worker_id, size_t young_cset_length);
  86   ~G1ParScanThreadState();
  87 
  88   void set_ref_processor(ReferenceProcessor* rp) { _scanner.set_ref_processor(rp); }
  89 
  90 #ifdef ASSERT
  91   bool queue_is_empty() const { return _refs->is_empty(); }
  92 
  93   bool verify_ref(narrowOop* ref) const;
  94   bool verify_ref(oop* ref) const;
  95   bool verify_task(StarTask ref) const;
  96 #endif // ASSERT
  97 
  98   template <class T> void push_on_queue(T* ref);
  99 
 100   template <class T> void update_rs(HeapRegion* from, T* p, uint tid) {
 101     // If the new value of the field points to the same region or
 102     // is the to-space, we don't need to include it in the Rset updates.
 103     if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) {
 104       size_t card_index = ctbs()->index_for(p);
 105       // If the card hasn't been added to the buffer, do it.
 106       if (ctbs()->mark_card_deferred(card_index)) {
 107         dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index));
 108       }
 109     }
 110   }
 111 
 112   uint worker_id() { return _worker_id; }
 113 
 114   // Returns the current amount of waste due to alignment or not being able to fit
 115   // objects within LABs and the undo waste.
 116   virtual void waste(size_t& wasted, size_t& undo_wasted);
 117 
 118   size_t* surviving_young_words() {
 119     // We add one to hide entry 0 which accumulates surviving words for
 120     // age -1 regions (i.e. non-young ones)
 121     return _surviving_young_words + 1;
 122   }
 123 
 124   void flush(size_t* surviving_young_words);
 125 
 126  private:
 127   #define G1_PARTIAL_ARRAY_MASK 0x2
 128 
 129   inline bool has_partial_array_mask(oop* ref) const {
 130     return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
 131   }
 132 
 133   // We never encode partial array oops as narrowOop*, so return false immediately.
 134   // This allows the compiler to create optimized code when popping references from
 135   // the work queue.
 136   inline bool has_partial_array_mask(narrowOop* ref) const {
 137     assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
 138     return false;
 139   }
 140 
 141   // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
 142   // We always encode partial arrays as regular oop, to allow the
 143   // specialization for has_partial_array_mask() for narrowOops above.
 144   // This means that unintentional use of this method with narrowOops are caught
 145   // by the compiler.
 146   inline oop* set_partial_array_mask(oop obj) const {
 147     assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
 148     return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
 149   }
 150 
 151   inline oop clear_partial_array_mask(oop* ref) const {
 152     return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
 153   }
 154 
 155   inline void do_oop_partial_array(oop* p);
 156 
 157   // This method is applied to the fields of the objects that have just been copied.
 158   template <class T> inline void do_oop_evac(T* p, HeapRegion* from);
 159 
 160   template <class T> inline void deal_with_reference(T* ref_to_scan);
 161 
 162   inline void dispatch_reference(StarTask ref);
 163 
 164   // Tries to allocate word_sz in the PLAB of the next "generation" after trying to
 165   // allocate into dest. State is the original (source) cset state for the object
 166   // that is allocated for. Previous_plab_refill_failed indicates whether previously
 167   // a PLAB refill into "state" failed.
 168   // Returns a non-NULL pointer if successful, and updates dest if required.
 169   // Also determines whether we should continue to try to allocate into the various
 170   // generations or just end trying to allocate.
 171   HeapWord* allocate_in_next_plab(InCSetState const state,
 172                                   InCSetState* dest,
 173                                   size_t word_sz,
 174                                   AllocationContext_t const context,
 175                                   bool previous_plab_refill_failed);
 176 
 177   inline InCSetState next_state(InCSetState const state, markOop const m, uint& age);
 178 
 179   void report_promotion_event(InCSetState const dest_state,
 180                               oop const old, size_t word_sz, uint age,
 181                               HeapWord * const obj_ptr, const AllocationContext_t context) const;
 182  public:
 183 
 184   oop copy_to_survivor_space(InCSetState const state, oop const obj, markOop const old_mark);
 185 
 186   void trim_queue();
 187 
 188   inline void steal_and_trim_queue(RefToScanQueueSet *task_queues);
 189 
 190   // An attempt to evacuate "obj" has failed; take necessary steps.
 191   oop handle_evacuation_failure_par(oop obj, markOop m);
 192 };
 193 
 194 class G1ParScanThreadStateSet : public StackObj {
 195   G1CollectedHeap* _g1h;
 196   G1ParScanThreadState** _states;
 197   size_t* _surviving_young_words_total;
 198   size_t* _cards_scanned;
 199   size_t _total_cards_scanned;
 200   uint _n_workers;
 201   bool _flushed;
 202 
 203  public:
 204   G1ParScanThreadStateSet(G1CollectedHeap* g1h, uint n_workers, size_t young_cset_length) :
 205       _g1h(g1h),
 206       _states(NEW_C_HEAP_ARRAY(G1ParScanThreadState*, n_workers, mtGC)),
 207       _surviving_young_words_total(NEW_C_HEAP_ARRAY(size_t, young_cset_length, mtGC)),
 208       _cards_scanned(NEW_C_HEAP_ARRAY(size_t, n_workers, mtGC)),
 209       _total_cards_scanned(0),
 210       _n_workers(n_workers),
 211       _flushed(false) {
 212     for (uint i = 0; i < n_workers; ++i) {
 213       _states[i] = new_par_scan_state(i, young_cset_length);
 214     }
 215     memset(_surviving_young_words_total, 0, young_cset_length * sizeof(size_t));
 216     memset(_cards_scanned, 0, n_workers * sizeof(size_t));
 217   }
 218 
 219   ~G1ParScanThreadStateSet() {
 220     assert(_flushed, "thread local state from the per thread states should have been flushed");
 221     FREE_C_HEAP_ARRAY(G1ParScanThreadState*, _states);
 222     FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_total);
 223     FREE_C_HEAP_ARRAY(size_t, _cards_scanned);
 224   }
 225 
 226   void flush();
 227 
 228   G1ParScanThreadState* state_for_worker(uint worker_id);
 229 
 230   void add_cards_scanned(uint worker_id, size_t cards_scanned);
 231   size_t total_cards_scanned() const;
 232   const size_t* surviving_young_words() const;
 233 
 234  private:
 235   G1ParScanThreadState* new_par_scan_state(uint worker_id, size_t young_cset_length);
 236 };
 237 
 238 #endif // SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP
--- EOF ---