< prev index next >

src/share/vm/gc_implementation/shenandoah/shenandoahHeuristics.hpp

Print this page
rev 10533 : [backport] Replace risky SBS::need_update_refs_barrier with straightforward check
rev 10584 : [backport] Move periodic GC decision making to GC heuristics base class
rev 10606 : [backport] Adaptive/Traversal heuristics rewrite for allocation rate
rev 10607 : [backport] Remove ShHeuristics::print_threshold
rev 10637 : [backport] Purge partial heuristics and connection matrix infrastructure


  36       FLAG_SET_DEFAULT(name, false);                                        \
  37     }                                                                       \
  38   } while (0)
  39 
  40 #define SHENANDOAH_ERGO_ENABLE_FLAG(name)                                   \
  41   do {                                                                      \
  42     if (FLAG_IS_DEFAULT(name) && !(name)) {                                 \
  43       log_info(gc)("Heuristics ergonomically sets -XX:+" #name);            \
  44       FLAG_SET_DEFAULT(name, true);                                         \
  45     }                                                                       \
  46   } while (0)
  47 
  48 #define SHENANDOAH_ERGO_OVERRIDE_DEFAULT(name, value)                       \
  49   do {                                                                      \
  50     if (FLAG_IS_DEFAULT(name)) {                                            \
  51       log_info(gc)("Heuristics ergonomically sets -XX:" #name "=" #value);  \
  52       FLAG_SET_DEFAULT(name, value);                                        \
  53     }                                                                       \
  54   } while (0)
  55 
  56 
  57 class ShenandoahCollectionSet;
  58 class ShenandoahHeapRegion;
  59 
  60 class ShenandoahHeuristics : public CHeapObj<mtGC> {




  61 protected:
  62   typedef struct {
  63     ShenandoahHeapRegion* _region;
  64     size_t _garbage;
  65     uint64_t _seqnum_last_alloc;
  66   } RegionData;
  67 
  68   typedef struct {
  69     ShenandoahHeapRegion* _region;
  70     size_t _connections;
  71   } RegionConnections;
  72 
  73   bool _update_refs_early;
  74   bool _update_refs_adaptive;
  75 
  76   RegionData* _region_data;
  77   size_t _region_data_size;
  78 
  79   RegionConnections* _region_connects;
  80   size_t _region_connects_size;
  81 
  82   uint _degenerated_cycles_in_a_row;
  83   uint _successful_cycles_in_a_row;
  84 
  85   size_t _bytes_in_cset;
  86 

  87   double _last_cycle_end;
  88 




  89   static int compare_by_garbage(RegionData a, RegionData b);
  90   static int compare_by_alloc_seq_ascending(RegionData a, RegionData b);
  91   static int compare_by_alloc_seq_descending(RegionData a, RegionData b);
  92   static int compare_by_connects(RegionConnections a, RegionConnections b);
  93 
  94   RegionData* get_region_data_cache(size_t num);
  95 
  96   RegionConnections* get_region_connects_cache(size_t num);
  97 
  98   virtual void choose_collection_set_from_regiondata(ShenandoahCollectionSet* set,
  99                                                      RegionData* data, size_t data_size,
 100                                                      size_t free) = 0;
 101 
 102 public:
 103 
 104   ShenandoahHeuristics();
 105   virtual ~ShenandoahHeuristics();
 106 
 107   void record_gc_start();
 108 
 109   void record_gc_end();
 110 
 111   virtual void record_cycle_start();
 112 
 113   virtual void record_cycle_end();
 114 
 115   virtual void record_phase_time(ShenandoahPhaseTimings::Phase phase, double secs);
 116 
 117   virtual void print_thresholds();
 118 
 119   virtual bool should_start_normal_gc() const = 0;
 120 
 121   virtual bool should_start_update_refs();
 122 
 123   virtual bool update_refs() const;
 124 
 125   virtual bool should_degenerate_cycle();
 126 
 127   virtual void record_success_concurrent();
 128 
 129   virtual void record_success_degenerated();
 130 
 131   virtual void record_success_full();
 132 
 133   virtual void record_allocation_failure_gc();
 134 
 135   virtual void record_explicit_gc();
 136 
 137   virtual void record_peak_occupancy();
 138 
 139   virtual void start_choose_collection_set() {
 140   }
 141   virtual void end_choose_collection_set() {
 142   }
 143 
 144   virtual void choose_collection_set(ShenandoahCollectionSet* collection_set);
 145 
 146   virtual bool should_process_references();
 147 
 148   virtual bool should_unload_classes();
 149 
 150   virtual const char* name() = 0;
 151   virtual bool is_diagnostic() = 0;
 152   virtual bool is_experimental() = 0;
 153   virtual void initialize();
 154 
 155 };
 156 
 157 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEURISTICS_HPP


  36       FLAG_SET_DEFAULT(name, false);                                        \
  37     }                                                                       \
  38   } while (0)
  39 
  40 #define SHENANDOAH_ERGO_ENABLE_FLAG(name)                                   \
  41   do {                                                                      \
  42     if (FLAG_IS_DEFAULT(name) && !(name)) {                                 \
  43       log_info(gc)("Heuristics ergonomically sets -XX:+" #name);            \
  44       FLAG_SET_DEFAULT(name, true);                                         \
  45     }                                                                       \
  46   } while (0)
  47 
  48 #define SHENANDOAH_ERGO_OVERRIDE_DEFAULT(name, value)                       \
  49   do {                                                                      \
  50     if (FLAG_IS_DEFAULT(name)) {                                            \
  51       log_info(gc)("Heuristics ergonomically sets -XX:" #name "=" #value);  \
  52       FLAG_SET_DEFAULT(name, value);                                        \
  53     }                                                                       \
  54   } while (0)
  55 

  56 class ShenandoahCollectionSet;
  57 class ShenandoahHeapRegion;
  58 
  59 class ShenandoahHeuristics : public CHeapObj<mtGC> {
  60   static const intx Concurrent_Adjust   =  1; // recover from penalties
  61   static const intx Degenerated_Penalty = 10; // how much to penalize average GC duration history on Degenerated GC
  62   static const intx Full_Penalty        = 20; // how much to penalize average GC duration history on Full GC
  63 
  64 protected:
  65   typedef struct {
  66     ShenandoahHeapRegion* _region;
  67     size_t _garbage;
  68     uint64_t _seqnum_last_alloc;
  69   } RegionData;
  70 





  71   bool _update_refs_early;
  72   bool _update_refs_adaptive;
  73 
  74   RegionData* _region_data;
  75   size_t _region_data_size;
  76 



  77   uint _degenerated_cycles_in_a_row;
  78   uint _successful_cycles_in_a_row;
  79 
  80   size_t _bytes_in_cset;
  81 
  82   double _cycle_start;
  83   double _last_cycle_end;
  84 
  85   size_t _gc_times_learned;
  86   size_t _gc_time_penalties;
  87   TruncatedSeq* _gc_time_history;
  88 
  89   static int compare_by_garbage(RegionData a, RegionData b);
  90   static int compare_by_alloc_seq_ascending(RegionData a, RegionData b);
  91   static int compare_by_alloc_seq_descending(RegionData a, RegionData b);

  92 
  93   RegionData* get_region_data_cache(size_t num);
  94 


  95   virtual void choose_collection_set_from_regiondata(ShenandoahCollectionSet* set,
  96                                                      RegionData* data, size_t data_size,
  97                                                      size_t free) = 0;
  98 
  99 public:
 100 
 101   ShenandoahHeuristics();
 102   virtual ~ShenandoahHeuristics();
 103 
 104   void record_gc_start();
 105 
 106   void record_gc_end();
 107 
 108   virtual void record_cycle_start();
 109 
 110   virtual void record_cycle_end();
 111 
 112   virtual void record_phase_time(ShenandoahPhaseTimings::Phase phase, double secs);
 113 
 114   virtual bool should_start_normal_gc() const;


 115 
 116   virtual bool should_start_update_refs();
 117 


 118   virtual bool should_degenerate_cycle();
 119 
 120   virtual void record_success_concurrent();
 121 
 122   virtual void record_success_degenerated();
 123 
 124   virtual void record_success_full();
 125 
 126   virtual void record_allocation_failure_gc();
 127 
 128   virtual void record_explicit_gc();


 129 
 130   virtual void start_choose_collection_set() {
 131   }
 132   virtual void end_choose_collection_set() {
 133   }
 134 
 135   virtual void choose_collection_set(ShenandoahCollectionSet* collection_set);
 136 
 137   virtual bool should_process_references();
 138 
 139   virtual bool should_unload_classes();
 140 
 141   virtual const char* name() = 0;
 142   virtual bool is_diagnostic() = 0;
 143   virtual bool is_experimental() = 0;
 144   virtual void initialize();
 145 
 146 };
 147 
 148 #endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEURISTICS_HPP
< prev index next >