rev 13237 : imported patch 8183226-periodic-rem-set-summary-accesses-uninitialized-stuff
rev 13238 : imported patch 8183226-eridk-sjohanss-review
rev 13240 : imported patch 8183128-cleanup-refinecardtableentryclosure
rev 13241 : imported patch 8183128-erikd-review
rev 13242 : imported patch 8183539-remove-into-cset-dcqs
rev 13243 : [mq]: 8183121-add-information-about-scanned-skipped-cards-during-updaters

   1 /*
   2  * Copyright (c) 2001, 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_G1REMSET_HPP
  26 #define SHARE_VM_GC_G1_G1REMSET_HPP
  27 
  28 #include "gc/g1/dirtyCardQueue.hpp"
  29 #include "gc/g1/g1CardLiveData.hpp"
  30 #include "gc/g1/g1RemSetSummary.hpp"
  31 #include "gc/g1/heapRegion.hpp"
  32 #include "memory/allocation.hpp"
  33 #include "memory/iterator.hpp"
  34 
  35 // A G1RemSet provides ways of iterating over pointers into a selected
  36 // collection set.
  37 
  38 class BitMap;
  39 class CardTableModRefBS;
  40 class G1BlockOffsetTable;
  41 class CodeBlobClosure;
  42 class G1CollectedHeap;
  43 class G1HotCardCache;
  44 class G1RemSetScanState;
  45 class G1ParScanThreadState;
  46 class G1Policy;
  47 class G1SATBCardTableModRefBS;
  48 class G1ScanObjsDuringScanRSClosure;
  49 class G1ScanObjsDuringUpdateRSClosure;
  50 class HeapRegionClaimer;
  51 
  52 // A G1RemSet in which each heap region has a rem set that records the
  53 // external heap references into it.  Uses a mod ref bs to track updates,
  54 // so that they can be used to update the individual region remsets.
  55 class G1RemSet: public CHeapObj<mtGC> {
  56 private:
  57   G1RemSetScanState* _scan_state;
  58   G1CardLiveData _card_live_data;
  59 
  60   G1RemSetSummary _prev_period_summary;
  61 
  62   // Scan all remembered sets of the collection set for references into the collection
  63   // set.
  64   void scan_rem_set(G1ParScanThreadState* pss,
  65                     CodeBlobClosure* heap_region_codeblobs,
  66                     uint worker_i);
  67 
  68   // Flush remaining refinement buffers for cross-region references to either evacuate references
  69   // into the collection set or update the remembered set.
  70   void update_rem_set(G1ParScanThreadState* pss, uint worker_i);
  71 
  72   G1CollectedHeap* _g1;
  73   size_t _num_conc_refined_cards; // Number of cards refined concurrently to the mutator.
  74 
  75   CardTableModRefBS*     _ct_bs;
  76   G1Policy*              _g1p;
  77   G1HotCardCache*        _hot_card_cache;
  78 
  79 public:
  80   // Gives an approximation on how many threads can be expected to add records to
  81   // a remembered set in parallel. This can be used for sizing data structures to
  82   // decrease performance losses due to data structure sharing.
  83   // Examples for quantities that influence this value are the maximum number of
  84   // mutator threads, maximum number of concurrent refinement or GC threads.
  85   static uint num_par_rem_sets();
  86 
  87   // Initialize data that depends on the heap size being known.
  88   void initialize(size_t capacity, uint max_regions);
  89 
  90   // This is called to reset dual hash tables after the gc pause
  91   // is finished and the initial hash table is no longer being
  92   // scanned.
  93   void cleanupHRRS();
  94 
  95   G1RemSet(G1CollectedHeap* g1,
  96            CardTableModRefBS* ct_bs,
  97            G1HotCardCache* hot_card_cache);
  98   ~G1RemSet();
  99 
 100   // Process all oops in the collection set from the cards in the refinement buffers and
 101   // remembered sets using pss.
 102   //
 103   // Further applies heap_region_codeblobs on the oops of the unmarked nmethods on the strong code
 104   // roots list for each region in the collection set.
 105   void oops_into_collection_set_do(G1ParScanThreadState* pss,
 106                                    CodeBlobClosure* heap_region_codeblobs,
 107                                    uint worker_i);
 108 
 109   // Prepare for and cleanup after an oops_into_collection_set_do
 110   // call.  Must call each of these once before and after (in sequential
 111   // code) any thread calls oops_into_collection_set_do.
 112   void prepare_for_oops_into_collection_set_do();
 113   void cleanup_after_oops_into_collection_set_do();
 114 
 115   G1RemSetScanState* scan_state() const { return _scan_state; }
 116 
 117   // Record, if necessary, the fact that *p (where "p" is in region "from",
 118   // which is required to be non-NULL) has changed to a new non-NULL value.
 119   template <class T> void par_write_ref(HeapRegion* from, T* p, uint tid);
 120 
 121   // Eliminates any remembered set entries that correspond to dead heap ranges.
 122   void scrub(uint worker_num, HeapRegionClaimer* hrclaimer);
 123 
 124   // Refine the card corresponding to "card_ptr". Safe to be called concurrently
 125   // to the mutator.
 126   void refine_card_concurrently(jbyte* card_ptr,
 127                                 uint worker_i);
 128 
 129   // Refine the card corresponding to "card_ptr", applying the given closure to
 130   // all references found.Must only be called during gc.
 131   void refine_card_during_gc(jbyte* card_ptr, G1ScanObjsDuringUpdateRSClosure* update_rs_cl);

 132 
 133   // Print accumulated summary info from the start of the VM.
 134   void print_summary_info();
 135 
 136   // Print accumulated summary info from the last time called.
 137   void print_periodic_summary_info(const char* header, uint period_count);
 138 
 139   size_t num_conc_refined_cards() const { return _num_conc_refined_cards; }
 140 
 141   void create_card_live_data(WorkGang* workers, G1CMBitMap* mark_bitmap);
 142   void finalize_card_live_data(WorkGang* workers, G1CMBitMap* mark_bitmap);
 143 
 144   // Verify that the liveness count data created concurrently matches one created
 145   // during this safepoint.
 146   void verify_card_live_data(WorkGang* workers, G1CMBitMap* actual_bitmap);
 147 
 148   void clear_card_live_data(WorkGang* workers);
 149 
 150 #ifdef ASSERT
 151   void verify_card_live_data_is_clear();
 152 #endif
 153 };
 154 
 155 class G1ScanRSForRegionClosure : public HeapRegionClosure {
 156   G1RemSetScanState* _scan_state;
 157 
 158   size_t _cards_scanned;
 159   size_t _cards_claimed;
 160   size_t _cards_skipped;
 161 
 162   G1CollectedHeap* _g1h;
 163 
 164   G1ScanObjsDuringScanRSClosure* _scan_objs_on_card_cl;
 165   CodeBlobClosure* _code_root_cl;
 166 
 167   G1BlockOffsetTable* _bot;
 168   G1SATBCardTableModRefBS *_ct_bs;
 169 
 170   double _strong_code_root_scan_time_sec;
 171   uint   _worker_i;
 172 
 173   void claim_card(size_t card_index, const uint region_idx_for_card);
 174   void scan_card(MemRegion mr, uint region_idx_for_card);
 175   void scan_strong_code_roots(HeapRegion* r);
 176 public:
 177   G1ScanRSForRegionClosure(G1RemSetScanState* scan_state,
 178                            G1ScanObjsDuringScanRSClosure* scan_obj_on_card,
 179                            CodeBlobClosure* code_root_cl,
 180                            uint worker_i);
 181 
 182   bool doHeapRegion(HeapRegion* r);
 183 
 184   double strong_code_root_scan_time_sec() {
 185     return _strong_code_root_scan_time_sec;
 186   }
 187 
 188   size_t cards_scanned() const { return _cards_scanned; }
 189   size_t cards_claimed() const { return _cards_claimed; }
 190   size_t cards_skipped() const { return _cards_skipped; }
 191 };
 192 
 193 class RebuildRSOopClosure: public ExtendedOopClosure {
 194   HeapRegion* _from;
 195   G1RemSet* _rs;
 196   uint _worker_i;
 197 
 198   template <class T> void do_oop_work(T* p);
 199 
 200 public:
 201   RebuildRSOopClosure(G1RemSet* rs, uint worker_i = 0) :
 202     _from(NULL), _rs(rs), _worker_i(worker_i)
 203   {}
 204 
 205   void set_from(HeapRegion* from) {
 206     assert(from != NULL, "from region must be non-NULL");
 207     _from = from;
 208   }
 209 
 210   virtual void do_oop(narrowOop* p) { do_oop_work(p); }
 211   virtual void do_oop(oop* p)       { do_oop_work(p); }
 212 };
 213 
 214 #endif // SHARE_VM_GC_G1_G1REMSET_HPP
--- EOF ---