Description:

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)
and epoll(4). 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. Libevent should compile on Linux, *BSD, Mac OS X,
Solaris and Windows.