[FFmpeg-devel] [PATCH] avutil: fix data race in av_get_cpu_flags()

[Michael Niedermayer]

On Tue, Dec 06, 2016 at 06:16:13PM -0800, Wan-Teh Chang wrote:
> Make the one-time initialization in av_get_cpu_flags() thread-safe. The
> static variable |cpu_flags| in libavutil/cpu.c is read and written using
> normal load and store operations. These are considered as data races.
> The fix is to use atomic load and store operations.
> 
> The fix can be verified by running the libavutil/tests/cpu_init.c test
> program under ThreadSanitizer:
>     ./configure --toolchain=clang-tsan
>     make libavutil/tests/cpu_init
>     libavutil/tests/cpu_init
> 
> There should be no warnings from ThreadSanitizer.
> 
> Co-author: Dmitry Vyukov of Google, who suggested the data race fix.
> 
> Signed-off-by: Wan-Teh Chang <wtc at google.com>
> ---
>  libavutil/cpu.c | 12 +++++++-----
>  libavutil/cpu.h |  2 --
>  2 files changed, 7 insertions(+), 7 deletions(-)

applied

thx

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

Into a blind darkness they enter who follow after the Ignorance,
they as if into a greater darkness enter who devote themselves
to the Knowledge alone. -- Isha Upanishad
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