Re: [screen-devel] Why not nonblock by default?

[Juergen Weigert]

On Jul 01, 09 09:26:11 -0700, Micah Cowan wrote:
> >> Juergen, I'm not following what the alarm() gives us over a nonblock
> >> with a sufficiently high value. 
> > 
> > You are right. I was under impression that nonblock is a boolean.
> > Actually nonblock also allows us to specify a timeout.
> > This is exactly what I was looking for!
> 
> So, does this mean you approve of setting nonblock to something like,
> say, 5-10 seconds by default? The main problem I want to avoid, is that
> once a display gets locked up (perhaps it's inflooping?), there's no way
> to set that display's nonblock, since the attempt will try to contact
> the attacher again :\

Yes. Keeping the session alive has priority over keeping the scrollback
accurate.  Who would argue against that? :-)

ALthough, I have raised doubt, that only setting a default timeout 
may not actually help.
I'd also like to see some prominent marker in the scrollback 
where output was dropped due to nonblock.

        cheers, 
                Jw-

> 
> >> Don't _both_ cases result in loss to the
> >> scrollback? If it's just the Msg() thing, we could make that the normal
> >> behavior for nonblock, too... Maybe I just don't properly understand how
> >> nonblock works?
> > 
> > When I suggested alarm(), I quickly browsed the code, and saw several calls
> > to write(), that were not guarded with any timeout. So I wonder, how this
> > nonblock timeout could work in case of write syscall not returning....
> 
> Yeah, good point. At some point we should check through the code to make
> sure that everything obeys the nonblock setting.
> 
> - --
> Micah J. Cowan
> Programmer, musician, typesetting enthusiast, gamer.
> Maintainer of GNU Wget and GNU Teseq
> http://micah.cowan.name/
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