83 class Generation: public CHeapObj<mtGC> {
  84   friend class VMStructs;
  85  private:
  86   jlong _time_of_last_gc; // time when last gc on this generation happened (ms)
  87   MemRegion _prev_used_region; // for collectors that want to "remember" a value for
  88                                // used region at some specific point during collection.
  89 
  90   GCMemoryManager* _gc_manager;
  91 
  92  protected:
  93   // Minimum and maximum addresses for memory reserved (not necessarily
  94   // committed) for generation.
  95   // Used by card marking code. Must not overlap with address ranges of
  96   // other generations.
  97   MemRegion _reserved;
  98 
  99   // Memory area reserved for generation
 100   VirtualSpace _virtual_space;
 101 
 102   // ("Weak") Reference processing support
 103   SpanSubjectToDiscoveryClosure _span_discoverer;
 104   ReferenceProcessor* _ref_processor;
 105 
 106   // Performance Counters
 107   CollectorCounters* _gc_counters;
 108 
 109   // Statistics for garbage collection
 110   GCStats* _gc_stats;
 111 
 112   // Initialize the generation.
 113   Generation(ReservedSpace rs, size_t initial_byte_size);
 114 
 115   // Apply "cl->do_oop" to (the address of) (exactly) all the ref fields in
 116   // "sp" that point into younger generations.
 117   // The iteration is only over objects allocated at the start of the
 118   // iterations; objects allocated as a result of applying the closure are
 119   // not included.
 120   void younger_refs_in_space_iterate(Space* sp, OopsInGenClosure* cl, uint n_threads);
 121 
 122  public:
 123   // The set of possible generation kinds.

  83 class Generation: public CHeapObj<mtGC> {
  84   friend class VMStructs;
  85  private:
  86   jlong _time_of_last_gc; // time when last gc on this generation happened (ms)
  87   MemRegion _prev_used_region; // for collectors that want to "remember" a value for
  88                                // used region at some specific point during collection.
  89 
  90   GCMemoryManager* _gc_manager;
  91 
  92  protected:
  93   // Minimum and maximum addresses for memory reserved (not necessarily
  94   // committed) for generation.
  95   // Used by card marking code. Must not overlap with address ranges of
  96   // other generations.
  97   MemRegion _reserved;
  98 
  99   // Memory area reserved for generation
 100   VirtualSpace _virtual_space;
 101 
 102   // ("Weak") Reference processing support
 103   SpanSubjectToDiscoveryClosure _span_based_discoverer;
 104   ReferenceProcessor* _ref_processor;
 105 
 106   // Performance Counters
 107   CollectorCounters* _gc_counters;
 108 
 109   // Statistics for garbage collection
 110   GCStats* _gc_stats;
 111 
 112   // Initialize the generation.
 113   Generation(ReservedSpace rs, size_t initial_byte_size);
 114 
 115   // Apply "cl->do_oop" to (the address of) (exactly) all the ref fields in
 116   // "sp" that point into younger generations.
 117   // The iteration is only over objects allocated at the start of the
 118   // iterations; objects allocated as a result of applying the closure are
 119   // not included.
 120   void younger_refs_in_space_iterate(Space* sp, OopsInGenClosure* cl, uint n_threads);
 121 
 122  public:
 123   // The set of possible generation kinds.