[FFmpeg-devel] [PATCH v2 143/162] avcodec/aac*: Make initializing ff_aac_pow*sf_tab thread-safe

[Michael Niedermayer]

On Fri, Nov 20, 2020 at 08:33:08AM +0100, Andreas Rheinhardt wrote:
> This table is currently initialized up to three times: Once by the
> encoder and twice by the decoders (once by the fixed and once by the
> floating-point decoder); each of these initializations is guarded by an
> AVOnce, yet the fact that there are three of them implies that there
> might be data races (the fact that each entry is only written to once
> (to its final value) when initializing means that this is safe in
> practice, yet it is still undefined behaviour). Fix this by only
> initializing the table from one place that is guarded by one AVOnce.
> This also avoids unnecessary duplications of the init code.
> 
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavcodec/aacenc.c | 12 +----------
>  libavcodec/aactab.c | 52 +++++++++++++++++++++++++++++++++++++++++++++
>  libavcodec/aactab.h | 46 +--------------------------------------
>  3 files changed, 54 insertions(+), 56 deletions(-)

LGTM

thx

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

When the tyrant has disposed of foreign enemies by conquest or treaty, and
there is nothing more to fear from them, then he is always stirring up
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