aliasing bug
 n.

    A class of subtle programming errors that can arise in code that does
    dynamic allocation, esp. via malloc(3) or equivalent. If several pointers
    address (are aliases for) a given hunk of storage, it may happen that the
    storage is freed or reallocated (and thus moved) through one alias and then
    referenced through another, which may lead to subtle (and possibly
    intermittent) lossage depending on the state and the allocation history of
    the malloc arena. Avoidable by use of allocation strategies that never
    alias allocated core, or by use of higher-level languages, such as LISP,
    which employ a garbage collector (see GC). Also called a stale pointer
    bug. See also precedence lossage, smash the stack, fandango on core,
    memory leak, memory smash, overrun screw, spam.

    Historical note: Though this term is nowadays associated with C
    programming, it was already in use in a very similar sense in the Algol-60
    and FORTRAN communities in the 1960s.

	

	stale pointer bug
aliasing bug

    (Or "aliasing bug") A class of subtle
   programming errors that can arise in code that does dynamic
   allocation, especially via malloc or equivalent.

   If several pointers address (are "aliases for") a given hunk
   of storage, it may happen that the storage is freed or
   reallocated (and thus moved) through one alias and then
   referenced through another, which may lead to subtle (and
   possibly intermittent) lossage depending on the state and the
   allocation history of the malloc arena.  This bug can be
   avoided by never creating aliases for allocated memory, or by
   use of a higher-level language, such as Lisp, which
   employs a garbage collector.

   The term "aliasing bug" is nowadays associated with C
   programming, it was already in use in a very similar sense in
   the ALGOL 60 and Fortran communities in the 1960s.

   See also smash the stack, fandango on core, memory leak,
   memory smash, spam.

   [Jargon File]

   (1995-05-09)