1 /*
   2  * Copyright (c) 2014, 2017, 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/g1OopClosures.hpp"
  31 #include "gc/g1/g1Policy.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 G1EvacuationRootClosures;
  40 class HeapRegion;
  41 class outputStream;
  42 
  43 class G1ParScanThreadState : public CHeapObj<mtGC> {
  44  private:
  45   G1CollectedHeap* _g1h;
  46   RefToScanQueue*  _refs;
  47   DirtyCardQueue   _dcq;
  48   G1SATBCardTableModRefBS* _ct_bs;
  49   G1EvacuationRootClosures* _closures;
  50 
  51   G1PLABAllocator*  _plab_allocator;
  52 
  53   AgeTable          _age_table;
  54   InCSetState       _dest[InCSetState::Num];
  55   // Local tenuring threshold.
  56   uint              _tenuring_threshold;
  57   G1ScanEvacuatedObjClosure  _scanner;
  58 
  59   int  _hash_seed;
  60   uint _worker_id;
  61 
  62   // Map from young-age-index (0 == not young, 1 is youngest) to
  63   // surviving words. base is what we get back from the malloc call
  64   size_t* _surviving_young_words_base;
  65   // this points into the array, as we use the first few entries for padding
  66   size_t* _surviving_young_words;
  67 
  68   // Indicates whether in the last generation (old) there is no more space
  69   // available for allocation.
  70   bool _old_gen_is_full;
  71 
  72 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
  73 
  74   DirtyCardQueue& dirty_card_queue()             { return _dcq;  }
  75   G1SATBCardTableModRefBS* ctbs()                { return _ct_bs; }
  76 
  77   InCSetState dest(InCSetState original) const {
  78     assert(original.is_valid(),
  79            "Original state invalid: " CSETSTATE_FORMAT, original.value());
  80     assert(_dest[original.value()].is_valid_gen(),
  81            "Dest state is invalid: " CSETSTATE_FORMAT, _dest[original.value()].value());
  82     return _dest[original.value()];
  83   }
  84 
  85  public:
  86   G1ParScanThreadState(G1CollectedHeap* g1h, uint worker_id, size_t young_cset_length);
  87   virtual ~G1ParScanThreadState();
  88 
  89   void set_ref_processor(ReferenceProcessor* rp) { _scanner.set_ref_processor(rp); }
  90 
  91 #ifdef ASSERT
  92   bool queue_is_empty() const { return _refs->is_empty(); }
  93 
  94   bool verify_ref(narrowOop* ref) const;
  95   bool verify_ref(oop* ref) const;
  96   bool verify_task(StarTask ref) const;
  97 #endif // ASSERT
  98 
  99   template <class T> void do_oop_ext(T* ref);
 100   template <class T> void push_on_queue(T* ref);
 101 
 102   template <class T> void update_rs(HeapRegion* from, T* p, oop o) {
 103     assert(!HeapRegion::is_in_same_region(p, o), "Caller should have filtered out cross-region references already.");
 104     // If the field originates from the to-space, we don't need to include it
 105     // in the remembered set updates.
 106     if (!from->is_young()) {
 107       size_t card_index = ctbs()->index_for(p);
 108       // If the card hasn't been added to the buffer, do it.
 109       if (ctbs()->mark_card_deferred(card_index)) {
 110         dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index));
 111       }
 112     }
 113   }
 114 
 115   G1EvacuationRootClosures* closures() { return _closures; }
 116   uint worker_id() { return _worker_id; }
 117 
 118   // Returns the current amount of waste due to alignment or not being able to fit
 119   // objects within LABs and the undo waste.
 120   virtual void waste(size_t& wasted, size_t& undo_wasted);
 121 
 122   size_t* surviving_young_words() {
 123     // We add one to hide entry 0 which accumulates surviving words for
 124     // age -1 regions (i.e. non-young ones)
 125     return _surviving_young_words + 1;
 126   }
 127 
 128   void flush(size_t* surviving_young_words);
 129 
 130  private:
 131   #define G1_PARTIAL_ARRAY_MASK 0x2
 132 
 133   inline bool has_partial_array_mask(oop* ref) const {
 134     return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
 135   }
 136 
 137   // We never encode partial array oops as narrowOop*, so return false immediately.
 138   // This allows the compiler to create optimized code when popping references from
 139   // the work queue.
 140   inline bool has_partial_array_mask(narrowOop* ref) const {
 141     assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
 142     return false;
 143   }
 144 
 145   // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
 146   // We always encode partial arrays as regular oop, to allow the
 147   // specialization for has_partial_array_mask() for narrowOops above.
 148   // This means that unintentional use of this method with narrowOops are caught
 149   // by the compiler.
 150   inline oop* set_partial_array_mask(oop obj) const {
 151     assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
 152     return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
 153   }
 154 
 155   inline oop clear_partial_array_mask(oop* ref) const {
 156     return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
 157   }
 158 
 159   inline void do_oop_partial_array(oop* p);
 160 
 161   // This method is applied to the fields of the objects that have just been copied.
 162   template <class T> inline void do_oop_evac(T* p, HeapRegion* from);
 163 
 164   template <class T> inline void deal_with_reference(T* ref_to_scan);
 165 
 166   inline void dispatch_reference(StarTask ref);
 167 
 168   // Tries to allocate word_sz in the PLAB of the next "generation" after trying to
 169   // allocate into dest. State is the original (source) cset state for the object
 170   // that is allocated for. Previous_plab_refill_failed indicates whether previously
 171   // a PLAB refill into "state" failed.
 172   // Returns a non-NULL pointer if successful, and updates dest if required.
 173   // Also determines whether we should continue to try to allocate into the various
 174   // generations or just end trying to allocate.
 175   HeapWord* allocate_in_next_plab(InCSetState const state,
 176                                   InCSetState* dest,
 177                                   size_t word_sz,
 178                                   AllocationContext_t const context,
 179                                   bool previous_plab_refill_failed);
 180 
 181   inline InCSetState next_state(InCSetState const state, markOop const m, uint& age);
 182 
 183   void report_promotion_event(InCSetState const dest_state,
 184                               oop const old, size_t word_sz, uint age,
 185                               HeapWord * const obj_ptr, const AllocationContext_t context) const;
 186  public:
 187 
 188   oop copy_to_survivor_space(InCSetState const state, oop const obj, markOop const old_mark);
 189 
 190   void trim_queue();
 191 
 192   inline void steal_and_trim_queue(RefToScanQueueSet *task_queues);
 193 
 194   // An attempt to evacuate "obj" has failed; take necessary steps.
 195   oop handle_evacuation_failure_par(oop obj, markOop m);
 196 };
 197 
 198 class G1ParScanThreadStateSet : public StackObj {
 199   G1CollectedHeap* _g1h;
 200   G1ParScanThreadState** _states;
 201   size_t* _surviving_young_words_total;
 202   size_t _young_cset_length;
 203   uint _n_workers;
 204   bool _flushed;
 205 
 206  public:
 207   G1ParScanThreadStateSet(G1CollectedHeap* g1h, uint n_workers, size_t young_cset_length) :
 208       _g1h(g1h),
 209       _states(NEW_C_HEAP_ARRAY(G1ParScanThreadState*, n_workers, mtGC)),
 210       _surviving_young_words_total(NEW_C_HEAP_ARRAY(size_t, young_cset_length, mtGC)),
 211       _young_cset_length(young_cset_length),
 212       _n_workers(n_workers),
 213       _flushed(false) {
 214     for (uint i = 0; i < n_workers; ++i) {
 215       _states[i] = NULL;
 216     }
 217     memset(_surviving_young_words_total, 0, young_cset_length * sizeof(size_t));
 218   }
 219 
 220   ~G1ParScanThreadStateSet() {
 221     assert(_flushed, "thread local state from the per thread states should have been flushed");
 222     FREE_C_HEAP_ARRAY(G1ParScanThreadState*, _states);
 223     FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_total);
 224   }
 225 
 226   void flush();
 227 
 228   G1ParScanThreadState* state_for_worker(uint worker_id);
 229 
 230   const size_t* surviving_young_words() const;
 231 
 232  private:
 233   G1ParScanThreadState* new_par_scan_state(uint worker_id, size_t young_cset_length);
 234 };
 235 
 236 #endif // SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP