src/share/vm/gc/g1/g1CardCounts.cpp

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

*** 81,91 ****
      _reserved_max_card_num = mapper->reserved().byte_size();
      mapper->set_mapping_changed_listener(&_listener);
    }
  }
  
! uint G1CardCounts::add_card_count(jbyte* card_ptr) {
    // Returns the number of times the card has been refined.
    // If we failed to reserve/commit the counts table, return 0.
    // If card_ptr is beyond the committed end of the counts table,
    // return 0.
    // Otherwise return the actual count.
--- 81,91 ----
      _reserved_max_card_num = mapper->reserved().byte_size();
      mapper->set_mapping_changed_listener(&_listener);
    }
  }
  
! uint G1CardCounts::add_card_count(volatile jbyte* card_ptr) {
    // Returns the number of times the card has been refined.
    // If we failed to reserve/commit the counts table, return 0.
    // If card_ptr is beyond the committed end of the counts table,
    // return 0.
    // Otherwise return the actual count.
*** 116,130 ****
    clear_range(mr);
  }
  
  void G1CardCounts::clear_range(MemRegion mr) {
    if (has_count_table()) {
!     const jbyte* from_card_ptr = _ct_bs->byte_for_const(mr.start());
      // We use the last address in the range as the range could represent the
      // last region in the heap. In which case trying to find the card will be an
      // OOB access to the card table.
!     const jbyte* last_card_ptr = _ct_bs->byte_for_const(mr.last());
  
  #ifdef ASSERT
      HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);
      assert(start_addr == mr.start(), "MemRegion start must be aligned to a card.");
      HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr);
--- 116,130 ----
    clear_range(mr);
  }
  
  void G1CardCounts::clear_range(MemRegion mr) {
    if (has_count_table()) {
!     const volatile jbyte* from_card_ptr = _ct_bs->byte_for_const(mr.start());
      // We use the last address in the range as the range could represent the
      // last region in the heap. In which case trying to find the card will be an
      // OOB access to the card table.
!     const volatile jbyte* last_card_ptr = _ct_bs->byte_for_const(mr.last());
  
  #ifdef ASSERT
      HeapWord* start_addr = _ct_bs->addr_for(from_card_ptr);
      assert(start_addr == mr.start(), "MemRegion start must be aligned to a card.");
      HeapWord* last_addr = _ct_bs->addr_for(last_card_ptr);