deadlock

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.