reference counting

reference counting

   <programming> A {garbage collection} technique where each
   {memory cell} contains a count of the number of other cells
   which point to it.  If this count reaches zero the cell is
   freed and its {pointers} to other cells are followed to
   decrement their counts, and so on {recursively}.

   This technique cannot cope with {circular data structures}.
   Cells in such structures refer (indirectly) to themselves and
   so will never have a zero reference count.  This means they
   would never be reclaimed, even when there are no references
   from outside the structure.

   (1995-02-22)