[FFmpeg-devel] [PATCH] Don't needlessly reinitialize ff_cos_## tables.

Dale Curtis dalecurtis at chromium.org
Thu Oct 22 03:52:58 CEST 2015

On Tue, Oct 20, 2015 at 11:50 PM, Michael Niedermayer <
michael at niedermayer.cc> wrote:
> the last element to be written should be checked, so that if
> initialization is done by 2 threads at the same time, neither can
> return from this function without initialization having finished
> also the race detectors are broken if they complain about cases where
> a variable that has value a is set to value a, that cannot be part of
> a race, not even if a is written byte per byte instead of atomically
> unless theres something iam missing
> Is this something that can be fixed or disabled on the side of the
> race detectors?
> It might reduce false positives in FFmpeg and potentially other
> tools.

We can suppress it, which I think is more reasonable then the overhead it'd
take to make this "race" go away. I notice the sin tables are initialized
within the fft context so there's no "race." Is there a reason the cosine
tables aren't done this way?

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