An asynchronous event notification library (openssl) 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. Currently, libevent supports /dev/poll, kqueue(2), event ports, select(2), poll(2) and epoll(4). There is now a bufferevent type that supports SSL/TLS using the OpenSSL library. The code for this is build in a separate library, libevent_openssl, so that your programs don't need to link against OpenSSL unless they actually want SSL support.