[Vala] Questions on async functions

[Nor Jaidi Tuah <norjaidi tuah ubd edu bn>]

Q1.
What is the recommended way of aborting an
async function so that another invocation can
be made only after the previous one has
stopped, thus ensuring that there is at most
one invocation at any time?

Q2.
Any hope of getting the following replaced
with a better syntax? :-)

   Idle.add(async_function.callback);
   yield;

Why not simply:

   yield;

?

hand
Nor Jaidi Tuah