Busy waiting.

[vi]

Both thread pool and a single-threaded executor can't properly idle because of hard coded 1 millisecond interval for polling:

• fibers-rs/src/executor/thread_pool.rs

  Line 105 in 84b09e4

  thread::sleep(time::Duration::from_millis(1));

• fibers-rs/src/executor/in_place.rs

  Line 71 in 84b09e4

  self.poller.poll(Some(time::Duration::from_millis(1)))?;

Timeouts should only be specified while polling when there are active timers running.

[marcbrevoort-cyberhive]

This busy waiting results in high CPU usage. Are there any plans for turning this into a true async library so that it uses near-zero CPU when idle?