src/share/vm/gc/shared/cardTableRS.hpp

rev 10742 : Make fields used in lock-free algorithms volatile

*** 87,97 ****
  
    // An array that contains, for each generation, the card table value last
    // used as the current value for a younger_refs_do iteration of that
    // portion of the table. The perm gen is index 0. The young gen is index 1,
    // but will always have the value "clean_card". The old gen is index 2.
!   jbyte* _last_cur_val_in_gen;
  
    jbyte _cur_youngergen_card_val;
  
    // Number of generations, plus one for lingering PermGen issues in CardTableRS.
    static const int _regions_to_iterate = 3;
--- 87,97 ----
  
    // An array that contains, for each generation, the card table value last
    // used as the current value for a younger_refs_do iteration of that
    // portion of the table. The perm gen is index 0. The young gen is index 1,
    // but will always have the value "clean_card". The old gen is index 2.
!   volatile jbyte* _last_cur_val_in_gen;
  
    jbyte _cur_youngergen_card_val;
  
    // Number of generations, plus one for lingering PermGen issues in CardTableRS.
    static const int _regions_to_iterate = 3;
*** 134,144 ****
    // responsible for dirtying if the oop is still older-to-younger after
    // closure application.
    void younger_refs_iterate(Generation* g, OopsInGenClosure* blk, uint n_threads);
  
    void inline_write_ref_field_gc(void* field, oop new_val) {
!     jbyte* byte = _ct_bs->byte_for(field);
      *byte = youngergen_card;
    }
    void write_ref_field_gc_work(void* field, oop new_val) {
      inline_write_ref_field_gc(field, new_val);
    }
--- 134,144 ----
    // responsible for dirtying if the oop is still older-to-younger after
    // closure application.
    void younger_refs_iterate(Generation* g, OopsInGenClosure* blk, uint n_threads);
  
    void inline_write_ref_field_gc(void* field, oop new_val) {
!     volatile jbyte* byte = _ct_bs->byte_for(field);
      *byte = youngergen_card;
    }
    void write_ref_field_gc_work(void* field, oop new_val) {
      inline_write_ref_field_gc(field, new_val);
    }
*** 166,178 ****
  
    static uintx ct_max_alignment_constraint() {
      return CardTableModRefBSForCTRS::ct_max_alignment_constraint();
    }
  
!   jbyte* byte_for(void* p)     { return _ct_bs->byte_for(p); }
!   jbyte* byte_after(void* p)   { return _ct_bs->byte_after(p); }
!   HeapWord* addr_for(jbyte* p) { return _ct_bs->addr_for(p); }
  
    bool is_prev_nonclean_card_val(jbyte v) {
      return
        youngergen_card <= v &&
        v <= cur_youngergen_and_prev_nonclean_card &&
--- 166,178 ----
  
    static uintx ct_max_alignment_constraint() {
      return CardTableModRefBSForCTRS::ct_max_alignment_constraint();
    }
  
!   volatile jbyte* byte_for(void* p)     { return _ct_bs->byte_for(p); }
!   volatile jbyte* byte_after(void* p)   { return _ct_bs->byte_after(p); }
!   HeapWord* addr_for(volatile jbyte* p) { return _ct_bs->addr_for(p); }
  
    bool is_prev_nonclean_card_val(jbyte v) {
      return
        youngergen_card <= v &&
        v <= cur_youngergen_and_prev_nonclean_card &&
*** 190,205 ****
    CardTableRS* _ct;
    bool _is_par;
  private:
    // Clears the given card, return true if the corresponding card should be
    // processed.
!   inline bool clear_card(jbyte* entry);
    // Work methods called by the clear_card()
!   inline bool clear_card_serial(jbyte* entry);
!   inline bool clear_card_parallel(jbyte* entry);
    // check alignment of pointer
!   bool is_word_aligned(jbyte* entry);
  
  public:
    ClearNoncleanCardWrapper(DirtyCardToOopClosure* dirty_card_closure, CardTableRS* ct, bool is_par);
    void do_MemRegion(MemRegion mr);
  };
--- 190,205 ----
    CardTableRS* _ct;
    bool _is_par;
  private:
    // Clears the given card, return true if the corresponding card should be
    // processed.
!   inline bool clear_card(volatile jbyte* entry);
    // Work methods called by the clear_card()
!   inline bool clear_card_serial(volatile jbyte* entry);
!   inline bool clear_card_parallel(volatile jbyte* entry);
    // check alignment of pointer
!   bool is_word_aligned(volatile jbyte* entry);
  
  public:
    ClearNoncleanCardWrapper(DirtyCardToOopClosure* dirty_card_closure, CardTableRS* ct, bool is_par);
    void do_MemRegion(MemRegion mr);
  };