[FFmpeg-devel] [PATCH] Add the relaxed and acquire/releae flavors of avpriv_atomic_int_get and avpriv_atomic_int_set.

Ronald S. Bultje rsbultje at gmail.com
Tue Mar 1 21:40:43 CET 2016


On Tue, Mar 1, 2016 at 10:26 AM, Wan-Teh Chang <wtc-at-google.com at ffmpeg.org
> wrote:

> I'd like to reiterate that this is difficult for many good
> programmers.

I think you just hit the nail right on the head :). I think my personal
problem is that I don't quite understand what the actual problem is (your
wiki page on memory ordering was quite helpful here, thank you!), and how
the various release/acquire/memorybarrier/atomic functions help in solving
it (I still find this mind-bogglingly complex, I'll slowly read through the
documents you sent, but may take me a bit).

The fundamental problem being that it's difficult to understand, combined
with that we can't really grasp the severity of the issue (will files fail
to decode? will ffmpeg hang/crash? or is tsan just complaining for no
reason?), means that it's usually incredibly hard to do a good technical
review of these patches, so review may be slow'ish, sadly... I'm trying my
best but I'll make mistakes along the way.


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