Exception raised when trying to wake_up a task * that has been previously stopped

add ~priority s f creates an asynchronous task in s with * priority priority. * * The task executes the function f. * If the task returns a positive float, the function will be executed * again after this delay. Otherwise it goes to sleep, and * you can use wake_up to resume the task and execute f again. * Only a single call to f is done at each time. * Multiple wake_up while previous task has not * finished will result in sequentialized calls to f.

Wake up an asynchronous task. * Raises Stopped if the task has been stopped.

Stop and remove the asynchronous task. Doesn't quit a running task. * Raises Stopped if the task has been stopped.