CentOS 7 - Updates for x86_64: system environment/libraries: libevent
libevent - Abstract asynchronous event notification 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. libevent is meant to replace the asynchronous event
loop found in event driven network servers. An application just needs
to call event_dispatch() and can then add or remove events dynamically
without having to change the event loop.