src/share/vm/memory/barrierSet.hpp

rev 7318 : 8064721: The card tables only ever need two covering regions

*** 47,57 ****
    enum Flags {
      None                = 0,
      TargetUninitialized = 1
    };
  protected:
!   int _max_covered_regions;
    Name _kind;
  
  public:
  
    BarrierSet() { _kind = Uninit; }
--- 47,62 ----
    enum Flags {
      None                = 0,
      TargetUninitialized = 1
    };
  protected:
!   // Some barrier sets create tables whose elements correspond to parts of
!   // the heap; the CardTableModRefBS is an example.  Such barrier sets will
!   // normally reserve space for such tables, and commit parts of the table
!   // "covering" parts of the heap that are committed. At most one covered
!   // region per generation is needed.
!   static const int _max_covered_regions = 2;
    Name _kind;
  
  public:
  
    BarrierSet() { _kind = Uninit; }
*** 157,178 ****
    // virtual "_work" function below, which must implement the barrier.)
    inline void write_region(MemRegion mr);
  protected:
    virtual void write_region_work(MemRegion mr) = 0;
  public:
- 
-   // Some barrier sets create tables whose elements correspond to parts of
-   // the heap; the CardTableModRefBS is an example.  Such barrier sets will
-   // normally reserve space for such tables, and commit parts of the table
-   // "covering" parts of the heap that are committed.  The constructor is
-   // passed the maximum number of independently committable subregions to
-   // be covered, and the "resize_covered_region" function allows the
-   // sub-parts of the heap to inform the barrier set of changes of their
-   // sizes.
-   BarrierSet(int max_covered_regions) :
-     _max_covered_regions(max_covered_regions) {}
- 
    // Inform the BarrierSet that the the covered heap region that starts
    // with "base" has been changed to have the given size (possibly from 0,
    // for initialization.)
    virtual void resize_covered_region(MemRegion new_region) = 0;
  
--- 162,171 ----