deadlock

dead·lock   (děd'lŏk')    n.   A standstill resulting from the opposition of two unrelenting forces or factions. Sports A tied score. Computer Science A failure or inability to proceed due to two programs or devices both requiring a response from the other before completing an operation. tr. & intr.v.   dead·locked, dead·lock·ing, dead·locks To bring or come to a deadlock.

deadlock 

Main Entry: dead·lock
Pronunciation: 'ded-"läk
Function: noun
: a state of inaction resulting from the opposition of equally powerful uncompromising persons or factions: as a : the state of a jury unable to agree on a verdict —see also ALLEN CHARGE b : IMPASSE c : a state in which corporate directors are unable to perform their functions because of shareholder voting —deadlock verb

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.
[The Jargon File]
(2000-07-26)