ub.com/carllerche/mio"><code>mio</code></a> to interface with the operating
system's event queue. A call to <a href="struct.Reactor.html#method.poll"><code>Reactor::poll</code></a> results in in a single
call to <a href="https://docs.rs/mio/0.6/mio/struct.Poll.html#method.poll"><code>Poll::poll</code></a> which in turn results in a single call to the
operating system's selector.</p>
<p>The reactor maintains state for each registered I/O resource. This tracks
the executor task to notify when events are provi