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.