[FFmpeg-devel] [PATCH] lavd/sdl: make cross-thread flags volatile

Nicolas George george at nsup.org
Fri Feb 7 16:57:27 CET 2014

Le nonidi 19 pluviôse, an CCXXII, Lukasz Marek a écrit :
> Signed-off-by: Lukasz Marek <lukasz.m.luki at gmail.com>
> ---
>  libavdevice/sdl.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Does it fix anything in real-world? As far as I know, volatile is not enough
to ensure inter-threads synchronization in SMP environments: the variable
could be updated in what the compiler sees as the structure in memory, but a
memory barrier is necessary to ensure this change is forwarded from the
core's cache to the common memory.

I still need to look at what synchronization primitives were added in lavu
for the refcounted frames API.


  Nicolas George
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