deadlock


Also found in: Dictionary, Thesaurus, Medical, Legal, Acronyms, Idioms, Wikipedia.

deadlock

[′ded‚läk]
(computer science)
A situation in which a task in a multiprogramming system cannot proceed because it is waiting for an event that will never occur. Also known as deadly embrace; interlock; knot.

deadlock

1. A lock equipped with a dead bolt only.
2. A lock in which a bolt is moved by means of a key or thumb turn, and is positively stopped in its projected position.

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.
References in periodicals archive ?
Appropriately, Section 134 of the LLC Act deals in considerable detail with the risk of LLC deadlocks in a provision entitled "Judicial Dissolution Upon Application by a Member.
Deadlock will remain for the rest of the current series, but next year the format is unlikely to exist.
The X Factor Australia' Deadlock Sends Omar Dean Home (http://au.
This will lead to a deadlock in distributed systems where a set of processes wait indefinitely for each other to satisfy their requests.
Addressing a joint session of the Egyptian parliament's two chambers on Sunday, the Egyptian leader urged Washington and other Mideast peace brokers to "assume their responsibility" to break the deadlock in the peace process.
But she asked O'Leary to "come back to her" after the other judges had voted and she would take the decision to a deadlock.
The head of state advised Nepal to take all possible measures to find a way out of the political deadlock and to mitigate the sufferings of the general public," said president's Press Advisor Rajendra Dahal quoting Dr.
Earlier, Maoist Prachanda had expressed his optimism that prevailing political deadlock might end in the near future.
Parant added that he hopes another foreign mediation would solve the deadlock, referring to a Qatari offer to broker talks between the Lebanese leaders.
14) It must be told that if they deadlock, the defendant will be sentenced to a parole-eligible prison term.
In a statement issued on Wednesday, the Turkish Ministry of Foreign Affairs (MFA) said that "the Conference on Disarmament has approved its work program on 29 May 2009, in Geneva, after a deadlock of more than 10 years.
The closest either side came to breaking the deadlock at Flixton was when a strike from a Manchester City midfielder from 25 yards cannoned off the crossbar.