[FFmpeg-devel] [PATCH 1/4] lavc/parser: use C11 atomics

[Michael Niedermayer]

On Thu, Nov 30, 2017 at 11:55:03AM +0000, Rostislav Pehlivanov wrote:
> On 28 November 2017 at 01:26, Michael Niedermayer <michael at niedermayer.cc>
> wrote:
> 
> > On Mon, Nov 27, 2017 at 04:30:18AM +0000, Rostislav Pehlivanov wrote:
> > > Signed-off-by: Rostislav Pehlivanov <atomnuker at gmail.com>
> > > ---
> > >  libavcodec/parser.c | 14 ++++++++------
> > >  1 file changed, 8 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/libavcodec/parser.c b/libavcodec/parser.c
> > > index 670680ea7c..baf1de4d88 100644
> > > --- a/libavcodec/parser.c
> > > +++ b/libavcodec/parser.c
> > > @@ -23,30 +23,32 @@
> > >  #include <inttypes.h>
> > >  #include <stdint.h>
> > >  #include <string.h>
> > > +#include <stdatomic.h>
> > >
> > >  #include "libavutil/avassert.h"
> > > -#include "libavutil/atomic.h"
> > >  #include "libavutil/internal.h"
> > >  #include "libavutil/mem.h"
> > >
> > >  #include "internal.h"
> > >  #include "parser.h"
> > >
> > > -static AVCodecParser *av_first_parser = NULL;
> > > +static _Atomic(AVCodecParser *)av_first_parser = NULL;
> >
> > This doesnt build here
> >
> > libavcodec/parser.c:35:8: warning: return type defaults to ‘int’ [enabled
> > by default]
> >  static _Atomic(AVCodecParser *)av_first_parser = NULL;
> >         ^
> > libavcodec/parser.c: In function ‘_Atomic’:
> > libavcodec/parser.c:35:32: error: expected declaration specifiers before
> > ‘av_first_parser’
> >  static _Atomic(AVCodecParser *)av_first_parser = NULL;
> >                                 ^
> > libavcodec/parser.c:38:1: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or
> > ‘__attribute__’ before ‘{’ token
> >  {
> >  ^
> > libavcodec/parser.c:46:1: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or
> > ‘__attribute__’ before ‘{’ token
> >  {
> >  ^
> > libavcodec/parser.c:55:1: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__a
> >
> >
> > [...]
> > --
> > Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
> >
> > Observe your enemies, for they first find out your faults. -- Antisthenes
> >
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> >
> 
> Does the attached patch work?

>  parser.c |   14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 71f66a37fb46e29626f27da4658f34927e48033c  v2-0001-lavc-parser-use-C11-atomics.patch
> From b9ed59e9aff4a0fcc40f444f307c87acad55e139 Mon Sep 17 00:00:00 2001
> From: Rostislav Pehlivanov <atomnuker at gmail.com>
> Date: Mon, 27 Nov 2017 01:56:41 +0000
> Subject: [PATCH v2 1/2] lavc/parser: use C11 atomics
> 
> Signed-off-by: Rostislav Pehlivanov <atomnuker at gmail.com>
> ---
>  libavcodec/parser.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/libavcodec/parser.c b/libavcodec/parser.c
> index 670680ea7c..d6df62bf70 100644
> --- a/libavcodec/parser.c
> +++ b/libavcodec/parser.c
> @@ -23,30 +23,32 @@
>  #include <inttypes.h>
>  #include <stdint.h>
>  #include <string.h>
> +#include <stdatomic.h>
>  
>  #include "libavutil/avassert.h"
> -#include "libavutil/atomic.h"
>  #include "libavutil/internal.h"
>  #include "libavutil/mem.h"
>  
>  #include "internal.h"
>  #include "parser.h"
>  
> -static AVCodecParser *av_first_parser = NULL;
> +static _Atomic(AVCodecParser *) av_first_parser = NULL;

no


libavcodec/parser.c:35:8: warning: return type defaults to ‘int’ [enabled by default]
 static _Atomic(AVCodecParser *) av_first_parser = NULL;
        ^
libavcodec/parser.c: In function ‘_Atomic’:
libavcodec/parser.c:35:33: error: expected declaration specifiers before ‘av_first_parser’
 static _Atomic(AVCodecParser *) av_first_parser = NULL;

also see
compat/atomics/gcc/stdatomic.h

i think what you do is not supportd in that

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

Breaking DRM is a little like attempting to break through a door even
though the window is wide open and the only thing in the house is a bunch
of things you dont want and which you would get tomorrow for free anyway
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