Enable parking strategies

[Abso1ut3Zer0]

Hi! Has there been any discussion around enabling a parking strategy to the tokio runtime builder? I think the current strategy to park the thread is a great default, but there are scenarios where a user may want to trade off CPU usage for efficiency.

I'm thinking maybe there could be an optional timeout where the executor could busy spin checking for io for a certain time. Once the timeout expires, it would simply park the thread as normal.

I have a use case where I actually need to busy wait at all times, so a feature like this would be very helpful.

[mox692]

As far as I know, there is no such option. There seems to be an issue that might be referring to the same thing, though.

#4797