php-deluxe.net - description Futex

Futex

A futex (short for fast userspace mutual exclusion ) is a basic tool to realize lock (computer)ing and building higher-level locking abstractions such as semaphore (programming)s and POSIX mutexes on Linux kernel. They first appeared in the development kernel version 2.5.7; the semantics stabilized as of version 2.5.40, and they are present in the 2.6.x stable kernel series.

Futexes were created by Hubertus Franke (IBM Thomas J. Watson Research Center), Matthew Kirkwood, Ingo Molnar (Red Hat) and Rusty Russell (IBM Linux Technology Center).

A futex consists of a piece of .

= See also =

Synchronization

Fetch-and-add

= References =

Rusty Russell, fuss, futexes and furwocks: Fast Userlevel Locking in Linux , Ottawa Linux Symposium 2002, [http://www.linux.org.uk/~ajh/ols2002_proceedings.pdf.gz online]

= External links =

[http://ds9a.nl/futex-manpages/ Futex manpages]

[http://people.redhat.com/drepper/futex.pdf Futexes Are Tricky] (PDF, 11 pages), a paper explaining futexes and how to use them (Ulrich Drepper of Red Hat)