[FFmpeg-devel] [PATCH 05/13] lavc/jpeg2000dec: Thread init_tile()

[Michael Niedermayer]

On Wed, Jun 15, 2022 at 03:11:34PM +0200, Tomas Härdin wrote:
> tis 2022-06-14 klockan 23:11 +0200 skrev Michael Niedermayer:
> > On Tue, Jun 14, 2022 at 04:41:14PM +0200, Tomas Härdin wrote:
> > > 
> > 
> > >  jpeg2000dec.c |   30 +++++++++++++++---------------
> > >  1 file changed, 15 insertions(+), 15 deletions(-)
> > > 6fa2fbf99afee36ee73459863df0527a72663f43  0005-lavc-jpeg2000dec-
> > > Thread-init_tile.patch
> > > From 080ebdc9bad130098bff575f9ce690b8a522c9f7 Mon Sep 17 00:00:00
> > > 2001
> > > From: =?UTF-8?q?Tomas=20H=C3=A4rdin?= <git at haerdin.se>
> > > Date: Mon, 13 Jun 2022 15:09:17 +0200
> > > Subject: [PATCH 05/13] lavc/jpeg2000dec: Thread init_tile()
> > 
> > Causes segfaults
> > 
> > [jpeg2000 @ 0x2cf53380] End mismatch 149
> > [jpeg2000 @ 0x2cf53380] ==1439== Thread 6:
> > ==1439== Invalid read of size 4
> > ==1439==    at 0x9771F0: jpeg2000_mct_write_frame (in ffmpeg_g)
> > ==1439==    by 0x78BA6F: avcodec_default_execute2 (in ffmpeg_g)
> > ==1439==    by 0x97C0BB: jpeg2000_decode_frame (in ffmpeg_g)
> > ==1439==    by 0xA90F72: frame_worker_thread (in ffmpeg_g)
> > ==1439==    by 0x54046DA: start_thread (pthread_create.c:463)
> > ==1439==    by 0xF8F261E: clone (clone.S:95)
> > 
> > i will send you the sample privatly
> 
> This is because init_tile() fails. I had assumed errors were handled in
> some way like longjmp since the function already called execute2() but
> it seems the threading doesn't do any kind of magic for this.
> 
> Can we have execute2() return some kind of error code when one or more
> jobs fail? Either say FFMIN() of all errors or negative jobnr that
> failed? This would save on having to allocate an array for errors when
> we don't really care which exact jobs failed..

one could return a struct with error code, index and number of failed
ones or something. But then maybe just atomically setting some error flag
and leaving the API would be fine too.
Iam fine with either

thx


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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