Re: Timer scheduling and cancel-timer

[Tomohiro Matsuyama]

> On 01/20/2013 07:58 AM, Tomohiro Matsuyama wrote:
> >     (setq my-timer
> >           (run-with-timer
> >            nil 0.1
> >            (lambda ()
> >              (when my-timer
> >                (cancel-timer my-timer)
> >                (setq my-timer nil)
> >                (sit-for 0.3)))))
> > 
> > After evaluating this code several times, you may see "zombie" timers
> > in timer-list, though the code intends to keep at most one timer.
> 
> Hmm, isn't that due to a race in the above code?
> A timer can fire when a timer action is running.
> 
> Do you get zombie timers with the following?
> It should avoid the race.
> 
>     (setq my-timer
>           (run-with-timer
>            nil 0.1
>            (lambda ()
>              (let ((m my-timer))
>                (when m
>                  (cancel-timer m)
>                  (setq my-timer nil)
>                  (sit-for 0.3))))))
I still got zombie timers. Same if I replace sit-for with sleep-for.
No one can reproduce this problem?

Regards,
Tomohiro