Crate tokio_os_timer

This crate provides timers for use with tokio that rely on OS mechanisms for timer management rather than a separate timing mechanism like tokio-timer. This comes at somewhat increased overhead if you have many timers, but allows the timers to have any granularity supported by your operating system where tokio-timer can only support timers with a granularity of 1ms. In particular, the system timers usually support whatever granularity the underlying hardware supports (see "High-resolution timers" in time(7)), which on my laptop is 1ns! Realistically, you won't be able to make your timers higher resolution than how long system calls on your system take, which is usually on the order of hundreds of nanoseconds.

The current implementation uses timerfd_create(2) on Linux, and kqueue(2) timers on macOS and BSDs.

Structs

Delay	A future that completes a specified amount of time from its creation.
Interval	A stream that yields once every time a fixed amount of time elapses.