Libevent

libevent is an asynchronous event notification software library.

The libevent API provides a mechanism to execute a callback function when a specific event occurs on a file descriptor or after a timeout has been reached. Furthermore, libevent also support callbacks due to signals or regular timeouts.

libevent is meant to replace the event loop found in event-driven network servers. An application just needs to call event_dispatch() and then add or remove events dynamically without having to change the event loop.

Currently, libevent supports /dev/poll, kqueue(2), select(2), poll(2), epoll(4) and Solaris's event ports. It also has experimental support for real-time signals. The internal event mechanism is completely independent of the exposed event API, and a simple update of libevent can provide new functionality without having to redesign the applications. As a result, libevent allows for portable application development and provides the most scalable event notification mechanism available on an operating system.

Using callbacks on signals, libevent makes it easy to write secure signal handlers as none of the user supplied signal handling code runs in the signal's context.

Libevent has been developed by Niels Provos and released under a permissive free software licence.

Major version releases

*libevent 1.4 was released on November 11, 2007.
*libevent 1.3 was released on February 15, 2007.
*libevent 1.2 was released on October 15, 2006.
*libevent 1.1 was released on May 14, 2005.

External links

* [http://www.monkey.org/~provos/libevent/ libevent web page]
* [http://www.kegel.com/c10k.html Dan Kegel's "The C10K problem" web page]
* [http://liboop.ofb.net/ liboop - another asynchronous event notification library]
* [http://libev.schmorp.de/bench.html A benchmark by the libev author comparing libevent with libev, a similar library]