bug#12447: 24.1.50; Stuck in garbage collection on OS X

[Dmitry Gutov]

On 16.09.2012 18:54, Eli Zaretskii wrote:
> > Date: Sun, 16 Sep 2012 18:25:50 +0400
> > From: Dmitry Gutov <dgutov@yandex.ru>
> > CC: hanche@math.ntnu.no, 12447@debbugs.gnu.org
> >
> > > Perhaps the problem is that the value of 'difference' is not
> > > initialized:
> > >
> > >     while (CONSP (timers) || CONSP (idle_timers))
> > >       {
> > >         Lisp_Object timer = Qnil, idle_timer = Qnil;
> > >         EMACS_TIME timer_time, idle_timer_time;
> > >         EMACS_TIME difference;   <<<<<<<<<<<<<<<<<<<<<<<<<<<<
> > >
> > > and then never set to any specific value, until here:
> > >
> > >         else
> > >         /* When we encounter a timer that is still waiting,
> > >            return the amount of time to wait before it is ripe.  */
> > >         {
> > >           UNGCPRO;
> > >           return difference;
> > >         }
> > >
> > > which causes us return garbage, potentially zero, to timer_check.
> >
> > It's assigned to, though. When we encounter a timer that's not yet ripe.
>
> What if all of them are ripe?

I don't see the problem. The first timer is ripe? Fire it and return 
'nexttime'. Otherwise, return 'difference', which now has been assigned 
a value.
If we've reached the end of the list, again return 'nexttime', which is 
initialized with invalid_emacs_time () at the beginning of timer_check_2.

Anyway, I think the immediate problem is that the newly created timer 
can be considered ripe.