Definition: deadlock

Source: WordNet (r) 1.7

deadlock
     n : a situation in which no progress can be made: "reached an
         impasse on the negotiations" [syn: impasse, stalemate,
          standstill]

Source: Webster's Revised Unabridged Dictionary (1913)

Deadlock \Dead"lock`\, n.
   1. A lock which is not self-latching, but requires a key to
      throw the bolt forward.

   2. A counteraction of things, which produces an entire
      stoppage; a complete obstruction of action.

            Things are at a deadlock.             --London
                                                  Times.

            The Board is much more likely to be at a deadlock of
            two to two.                           --The Century.

Source: The Free On-line Dictionary of Computing (2003-OCT-10)

deadlock

   <parallel, programming> A situation where two or more
   processes are unable to proceed because each is waiting for
   one of the others to do something.

   A common example is a program waiting for output from a server
   while the server is waiting for more input from the
   controlling program before outputting anything.  It is
   reported that this particular flavour of deadlock is sometimes
   called a "starvation deadlock", though the term "starvation"
   is more properly used for situations where a program can never
   run simply because it never gets high enough priority.

   Another common flavour is "constipation", in which each
   process is trying to send stuff to the other but all buffers
   are full because nobody is reading anything).  See deadly
   embrace.

   Another example, common in database programming, is two
   processes that are sharing some resource (e.g. read access to
   a table) but then both decide to wait for exclusive
   (e.g. write) access.

   The term "deadly embrace" is mostly synonymous, though usually
   used only when exactly two processes are involved.  This is
   the more popular term in Europe, while deadlock predominates
   in the United States.

   Compare: livelock.  See also safety property, liveness
   property.

   [Jargon File]

   (2000-07-26)

Source: Jargon File (4.3.1, 29 Jun 2001)

deadlock n. 1. [techspeak] A situation wherein two or more processes
   are unable to proceed because each is waiting for one of the others to
   do something. A common example is a program communicating to a server,
   which may find itself waiting for output from the server before sending
   anything more to it, while the server is similarly waiting for more
   input from the controlling program before outputting anything. (It is
   reported that this particular flavor of deadlock is sometimes called a
   `starvation deadlock', though the term `starvation' is more properly
   used for situations where a program can never run simply because it
   never gets high enough priority. Another common flavor is
   `constipation', in which each process is trying to send stuff to the
   other but all buffers are full because nobody is reading anything.) See
   deadly embrace. 2. Also used of deadlock-like interactions between
   humans, as when two people meet in a narrow corridor, and each tries to
   be polite by moving aside to let the other pass, but they end up swaying
   from side to side without making any progress because they always move
   the same way at the same time.