[FFmpeg-devel] [PATCH] add timeout to udp_read
Sun Dec 27 13:45:21 CET 2009
On Sun, Dec 27, 2009 at 01:23:48PM +0100, Michael Niedermayer wrote:
> On Sun, Dec 27, 2009 at 01:15:55PM +0100, Reimar D?ffinger wrote:
> > On Sun, Dec 27, 2009 at 01:09:51PM +0100, Michael Niedermayer wrote:
> > > > I think it would also be a good idea to protect against the clock being
> > > > reset by detecting av_gettime() < network_timeout_reference_time and
> > > > adjusting network_timeout_reference_time.
> > >
> > > why?
> > > iam pretty sure ffmpeg will fail if the clock resets in 292
> > > million years
> > I don't mean wrap-around, I mean if someone (e.g. NTP) happens to adjust
> > the clock by e.g. a year, without an additional check our 10 ms timeout
> > would just have become a 1-year and 10 ms timeout.
> then we use the wrong clock
Well, I guess if there weren't the portability issues, av_gettime should
probably use clock_gettime(CLOCK_MONOTONIC, ...) instead of
> > It just seems reasonably simple enough to protect against this so I
> > thought it can't hurt...
> and if NTP slows the clock down like stoping it for a year ...
Which it won't. But apart from that it doesn't catch all issues, but it
would catch a somewhat relevant one with only 2 lines of code or so.
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