200   // Dirty the bytes corresponding to "mr" (not all of which must be
 201   // covered.)
 202   void dirty_MemRegion(MemRegion mr);
 203 
 204   // Clear (to clean_card) the bytes entirely contained within "mr" (not
 205   // all of which must be covered.)
 206   void clear_MemRegion(MemRegion mr);
 207 
 208   // *** Support for parallel card scanning.
 209 
 210   // This is an array, one element per covered region of the card table.
 211   // Each entry is itself an array, with one element per chunk in the
 212   // covered region.  Each entry of these arrays is the lowest non-clean
 213   // card of the corresponding chunk containing part of an object from the
 214   // previous chunk, or else NULL.
 215   typedef jbyte*  CardPtr;
 216   typedef CardPtr* CardArr;
 217   CardArr* _lowest_non_clean;
 218   size_t*  _lowest_non_clean_chunk_size;
 219   uintptr_t* _lowest_non_clean_base_chunk_index;
 220   int* _last_LNC_resizing_collection;
 221 
 222   // Initializes "lowest_non_clean" to point to the array for the region
 223   // covering "sp", and "lowest_non_clean_base_chunk_index" to the chunk
 224   // index of the corresponding to the first element of that array.
 225   // Ensures that these arrays are of sufficient size, allocating if necessary.
 226   // May be called by several threads concurrently.
 227   void get_LNC_array_for_space(Space* sp,
 228                                jbyte**& lowest_non_clean,
 229                                uintptr_t& lowest_non_clean_base_chunk_index,
 230                                size_t& lowest_non_clean_chunk_size);
 231 
 232   // Returns the number of chunks necessary to cover "mr".
 233   size_t chunks_to_cover(MemRegion mr) {
 234     return (size_t)(addr_to_chunk_index(mr.last()) -
 235                     addr_to_chunk_index(mr.start()) + 1);
 236   }
 237 
 238   // Returns the index of the chunk in a stride which
 239   // covers the given address.
 240   uintptr_t addr_to_chunk_index(const void* addr) {

 200   // Dirty the bytes corresponding to "mr" (not all of which must be
 201   // covered.)
 202   void dirty_MemRegion(MemRegion mr);
 203 
 204   // Clear (to clean_card) the bytes entirely contained within "mr" (not
 205   // all of which must be covered.)
 206   void clear_MemRegion(MemRegion mr);
 207 
 208   // *** Support for parallel card scanning.
 209 
 210   // This is an array, one element per covered region of the card table.
 211   // Each entry is itself an array, with one element per chunk in the
 212   // covered region.  Each entry of these arrays is the lowest non-clean
 213   // card of the corresponding chunk containing part of an object from the
 214   // previous chunk, or else NULL.
 215   typedef jbyte*  CardPtr;
 216   typedef CardPtr* CardArr;
 217   CardArr* _lowest_non_clean;
 218   size_t*  _lowest_non_clean_chunk_size;
 219   uintptr_t* _lowest_non_clean_base_chunk_index;
 220   volatile int* _last_LNC_resizing_collection;
 221 
 222   // Initializes "lowest_non_clean" to point to the array for the region
 223   // covering "sp", and "lowest_non_clean_base_chunk_index" to the chunk
 224   // index of the corresponding to the first element of that array.
 225   // Ensures that these arrays are of sufficient size, allocating if necessary.
 226   // May be called by several threads concurrently.
 227   void get_LNC_array_for_space(Space* sp,
 228                                jbyte**& lowest_non_clean,
 229                                uintptr_t& lowest_non_clean_base_chunk_index,
 230                                size_t& lowest_non_clean_chunk_size);
 231 
 232   // Returns the number of chunks necessary to cover "mr".
 233   size_t chunks_to_cover(MemRegion mr) {
 234     return (size_t)(addr_to_chunk_index(mr.last()) -
 235                     addr_to_chunk_index(mr.start()) + 1);
 236   }
 237 
 238   // Returns the index of the chunk in a stride which
 239   // covers the given address.
 240   uintptr_t addr_to_chunk_index(const void* addr) {