Crate fast_select

A mechanism for efficiently selecting between futures.

In async code, it is common to select between the completion of two or more futures. In this case, a naive implementation of select will poll each future during each wakeup. If the poll functions are expensive (because they takes locks, makes syscalls, or otherwise performs some computationally expensive task), then this can contribute to performance problems, especially in heavily-nested async code.

This crate contains an implementation of select that constructs a separate waker for each alternative future, allowing select’s poll implementation to identify exactly which futures are ready to be polled.

Structs

• FastSelect
  An object that can be used to efficiently select over alternative futures.

Traits

• Select
  A sealed trait for tuple types that can be selected over with FastSelect.