Re: run-with-idle-timer vs. run-at-time

[Óscar Fuentes]

Stefan Möding <s.moeding@gmail.com> writes:

> I'm trying to understand the difference between these two timers:
>
> (run-with-idle-timer 0 nil (lambda () (...)))
>
> (run-at-time 0 nil (lambda () (...)))
>
> I suspect there is a difference (see below) but I'm unable to come up with
> an example where it actually makes a difference.  Does anybody have an idea
> what condition could cause a different behavior?
>
> I can see from the documentation that `run-with-idle-timer' runs when
> Emacs is waiting for input.  But that also seems to be the case for
> `run-at-time'.  Is there a way that `run-at-time' might run at a time
> (earlier) when `run-with-idle-timer' would not?

Put this code in *scratch*, evaluate it and look at the contents of
*Messages*:

(progn
  (sleep-for 1)
  (run-at-time 0 nil 'message "running at time")
  (run-with-idle-timer 0 nil 'message "running at idle time")
  (sleep-for 1)
  (message "after run at time")
  (message ""))