[FFmpeg-devel] [PATCH] ffmpeg: make reading packets from thread blocking.

[Michael Niedermayer]

On Wed, Feb 19, 2014 at 04:48:14PM +0100, Nicolas George wrote:
> Le nonidi 9 brumaire, an CCXXII, Michael Niedermayer a écrit :
> > sadly not but i could reproduce it here again stuck in
> > fate-filter-amix-transition
> > but even running that 100 times shows no deadlock, seems it happens
> > only in a full fate run for me
> > 
> > also from looking at the code i see that finished could get set
> > while the other thread is waiting, i didnt check if that would deadlock
> > though
> 
> I believe that was the problem: I could produce a hang like the one
> described in this thread by adding a sleep() just before f->finished was
> set.
> 
> Thanks for the testing and the analysis.
> 
> > also iam not sure that fifo_cond should be reused
> 
> I am convinced this use is correct: fifo_cond covers any change to fifo_size
> and finished.
> 
> Here is an updated version of the patch. I ran FATE a couple of times, with
> various number of parallel processes and with and without the usleep(), and
> it did not hang.
> 

> I suspect lavu could offer this kind of synchronized message passing queue,
> though, and it could be a bit cleaner, especially for error passing. Shall I
> propose something for that?

iam not sure, do we have more places where this would be needed?



> 
> Regards,
> 
> -- 
>   Nicolas George

>  ffmpeg.c |   20 ++++++++++++++++++--
>  ffmpeg.h |    1 +
>  2 files changed, 19 insertions(+), 2 deletions(-)
> 1532139b4475592713b353f4f74d4be34e131426  0001-ffmpeg-make-reading-packets-from-thread-blocking.patch
> From 5893cf08736c0f6ebb1542afee72d6e6d66c70df Mon Sep 17 00:00:00 2001
> From: Nicolas George <george at nsup.org>
> Date: Fri, 25 Oct 2013 10:58:14 +0200
> Subject: [PATCH] ffmpeg: make reading packets from thread blocking.

LGTM


[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Republics decline into democracies and democracies degenerate into
despotisms. -- Aristotle
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