It took me a long time to arrive at the fact that it is only possible to
know that Emacs has already been idle for SECS seconds when we are
executing a callback for a run-with-idle-timer call with a delay arg of
SECS seconds. The docstring could state this in more detail.

On Fri, 21 Aug 2020, 23:25 Drew Adams, <drew.adams@oracle.com> wrote:

> > I think the part that makes it a bit confusing is
> > that we are talking about calling run-with-idle-timer
> > with a lower value of SECS from an already executing
> > callback for another run-with-idle-timer.
>
> Gee, what could possibly be confusing about that? ;-)
>
> (Especially if we don't say that explicitly.)
>
>
>