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src/share/vm/gc/g1/g1RemSet.hpp

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  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/g1RemSetSummary.hpp"
  29 
  30 // A G1RemSet provides ways of iterating over pointers into a selected
  31 // collection set.
  32 
  33 class G1CollectedHeap;
  34 class ConcurrentG1Refine;
  35 class G1ParPushHeapRSClosure;

  36 
  37 // A G1RemSet in which each heap region has a rem set that records the
  38 // external heap references into it.  Uses a mod ref bs to track updates,
  39 // so that they can be used to update the individual region remsets.
  40 
  41 class G1RemSet: public CHeapObj<mtGC> {
  42 private:
  43   G1RemSetSummary _prev_period_summary;
  44 
  45   // A DirtyCardQueueSet that is used to hold cards that contain
  46   // references into the current collection set. This is used to
  47   // update the remembered sets of the regions in the collection
  48   // set in the event of an evacuation failure.
  49   DirtyCardQueueSet _into_cset_dirty_card_queue_set;
  50 
  51 protected:
  52   G1CollectedHeap* _g1;
  53   size_t _conc_refine_cards;
  54   uint n_workers();
  55 
  56 protected:
  57   enum SomePrivateConstants {
  58     UpdateRStoMergeSync  = 0,
  59     MergeRStoDoDirtySync = 1,
  60     DoDirtySync          = 2,
  61     LastSync             = 3,
  62 
  63     SeqTask              = 0,
  64     NumSeqTasks          = 1
  65   };
  66 
  67   CardTableModRefBS*     _ct_bs;
  68   G1CollectorPolicy*     _g1p;
  69 
  70   ConcurrentG1Refine*    _cg1r;
  71 
  72   // Used for caching the closure that is responsible for scanning
  73   // references into the collection set.
  74   G1ParPushHeapRSClosure** _cset_rs_update_cl;
  75 
  76   // Print the given summary info
  77   virtual void print_summary_info(G1RemSetSummary * summary, const char * header = NULL);
  78 public:
  79   // This is called to reset dual hash tables after the gc pause
  80   // is finished and the initial hash table is no longer being
  81   // scanned.
  82   void cleanupHRRS();
  83 
  84   G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs);
  85   ~G1RemSet();
  86 
  87   // Invoke "blk->do_oop" on all pointers into the collection set
  88   // from objects in regions outside the collection set (having
  89   // invoked "blk->set_region" to set the "from" region correctly
  90   // beforehand.)
  91   //
  92   // Apply non_heap_roots on the oops of the unmarked nmethods
  93   // on the strong code roots list for each region in the
  94   // collection set.
  95   //
  96   // The "worker_i" param is for the parallel case where the id
  97   // of the worker thread calling this function can be helpful in


 129   // Requires "region_bm" and "card_bm" to be bitmaps with 1 bit per region
 130   // or card, respectively, such that a region or card with a corresponding
 131   // 0 bit contains no part of any live object.  Eliminates any remembered
 132   // set entries that correspond to dead heap ranges. "worker_num" is the
 133   // parallel thread id of the current thread, and "hrclaimer" is the
 134   // HeapRegionClaimer that should be used.
 135   void scrub(BitMap* region_bm, BitMap* card_bm, uint worker_num, HeapRegionClaimer* hrclaimer);
 136 
 137   // Refine the card corresponding to "card_ptr".
 138   // If check_for_refs_into_cset is true, a true result is returned
 139   // if the given card contains oops that have references into the
 140   // current collection set.
 141   virtual bool refine_card(jbyte* card_ptr,
 142                            uint worker_i,
 143                            bool check_for_refs_into_cset);
 144 
 145   // Print accumulated summary info from the start of the VM.
 146   virtual void print_summary_info();
 147 
 148   // Print accumulated summary info from the last time called.
 149   virtual void print_periodic_summary_info(const char* header);
 150 
 151   // Prepare remembered set for verification.
 152   virtual void prepare_for_verify();
 153 
 154   size_t conc_refine_cards() const {
 155     return _conc_refine_cards;
 156   }
 157 };
 158 
 159 class UpdateRSOopClosure: public ExtendedOopClosure {
 160   HeapRegion* _from;
 161   G1RemSet* _rs;
 162   uint _worker_i;
 163 
 164   template <class T> void do_oop_work(T* p);
 165 
 166 public:
 167   UpdateRSOopClosure(G1RemSet* rs, uint worker_i = 0) :
 168     _from(NULL), _rs(rs), _worker_i(worker_i)
 169   {}


  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/g1RemSetSummary.hpp"
  29 
  30 // A G1RemSet provides ways of iterating over pointers into a selected
  31 // collection set.
  32 
  33 class G1CollectedHeap;
  34 class ConcurrentG1Refine;
  35 class G1ParPushHeapRSClosure;
  36 class outputStream;
  37 
  38 // A G1RemSet in which each heap region has a rem set that records the
  39 // external heap references into it.  Uses a mod ref bs to track updates,
  40 // so that they can be used to update the individual region remsets.
  41 
  42 class G1RemSet: public CHeapObj<mtGC> {
  43 private:
  44   G1RemSetSummary _prev_period_summary;
  45 
  46   // A DirtyCardQueueSet that is used to hold cards that contain
  47   // references into the current collection set. This is used to
  48   // update the remembered sets of the regions in the collection
  49   // set in the event of an evacuation failure.
  50   DirtyCardQueueSet _into_cset_dirty_card_queue_set;
  51 
  52 protected:
  53   G1CollectedHeap* _g1;
  54   size_t _conc_refine_cards;
  55   uint n_workers();
  56 
  57 protected:
  58   enum SomePrivateConstants {
  59     UpdateRStoMergeSync  = 0,
  60     MergeRStoDoDirtySync = 1,
  61     DoDirtySync          = 2,
  62     LastSync             = 3,
  63 
  64     SeqTask              = 0,
  65     NumSeqTasks          = 1
  66   };
  67 
  68   CardTableModRefBS*     _ct_bs;
  69   G1CollectorPolicy*     _g1p;
  70 
  71   ConcurrentG1Refine*    _cg1r;
  72 
  73   // Used for caching the closure that is responsible for scanning
  74   // references into the collection set.
  75   G1ParPushHeapRSClosure** _cset_rs_update_cl;
  76 


  77 public:
  78   // This is called to reset dual hash tables after the gc pause
  79   // is finished and the initial hash table is no longer being
  80   // scanned.
  81   void cleanupHRRS();
  82 
  83   G1RemSet(G1CollectedHeap* g1, CardTableModRefBS* ct_bs);
  84   ~G1RemSet();
  85 
  86   // Invoke "blk->do_oop" on all pointers into the collection set
  87   // from objects in regions outside the collection set (having
  88   // invoked "blk->set_region" to set the "from" region correctly
  89   // beforehand.)
  90   //
  91   // Apply non_heap_roots on the oops of the unmarked nmethods
  92   // on the strong code roots list for each region in the
  93   // collection set.
  94   //
  95   // The "worker_i" param is for the parallel case where the id
  96   // of the worker thread calling this function can be helpful in


 128   // Requires "region_bm" and "card_bm" to be bitmaps with 1 bit per region
 129   // or card, respectively, such that a region or card with a corresponding
 130   // 0 bit contains no part of any live object.  Eliminates any remembered
 131   // set entries that correspond to dead heap ranges. "worker_num" is the
 132   // parallel thread id of the current thread, and "hrclaimer" is the
 133   // HeapRegionClaimer that should be used.
 134   void scrub(BitMap* region_bm, BitMap* card_bm, uint worker_num, HeapRegionClaimer* hrclaimer);
 135 
 136   // Refine the card corresponding to "card_ptr".
 137   // If check_for_refs_into_cset is true, a true result is returned
 138   // if the given card contains oops that have references into the
 139   // current collection set.
 140   virtual bool refine_card(jbyte* card_ptr,
 141                            uint worker_i,
 142                            bool check_for_refs_into_cset);
 143 
 144   // Print accumulated summary info from the start of the VM.
 145   virtual void print_summary_info();
 146 
 147   // Print accumulated summary info from the last time called.
 148   virtual void print_periodic_summary_info(const char* header, uint period_count);
 149 
 150   // Prepare remembered set for verification.
 151   virtual void prepare_for_verify();
 152 
 153   size_t conc_refine_cards() const {
 154     return _conc_refine_cards;
 155   }
 156 };
 157 
 158 class UpdateRSOopClosure: public ExtendedOopClosure {
 159   HeapRegion* _from;
 160   G1RemSet* _rs;
 161   uint _worker_i;
 162 
 163   template <class T> void do_oop_work(T* p);
 164 
 165 public:
 166   UpdateRSOopClosure(G1RemSet* rs, uint worker_i = 0) :
 167     _from(NULL), _rs(rs), _worker_i(worker_i)
 168   {}
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