maitake task system.
This module contains the code that spawns tasks on a scheduler, and
manages the lifecycle of tasks once they are spawned. This includes the
in-memory representation of spawned tasks (the
Task type), and the
handle used by the scheduler and other components of the runtime to
reference a task once it is spawned (the
Wakeris a handle for waking up a task by notifying its executor that it is ready to be run.