mio provides a high-performance timer implementation that can be used to wake up the event loop after a certain amount of time. It is optimized for relatively low-resolution timers (in the hundreds of milliseconds).
To register a timer, use EventLoop::timer. Like EventLoop::register, timer takes a Token, which will be passed to the handler when the timer expires. More on Tokens
event_loop.timer(1000, 10u);
Question for Carl: High resolution timers?