[FFmpeg-devel] [PATCH 1/3] avcodec/mlp: Make initializing CRCs thread-safe

[Andreas Rheinhardt]

Andreas Rheinhardt:
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
>  libavcodec/mlp.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/libavcodec/mlp.c b/libavcodec/mlp.c
> index ddbab60c4e..74363c3b95 100644
> --- a/libavcodec/mlp.c
> +++ b/libavcodec/mlp.c
> @@ -23,6 +23,7 @@
>  
>  #include "libavutil/crc.h"
>  #include "libavutil/intreadwrite.h"
> +#include "libavutil/thread.h"
>  #include "mlp.h"
>  
>  const uint8_t ff_mlp_huffman_tables[3][18][2] = {
> @@ -62,7 +63,6 @@ const uint64_t ff_mlp_channel_layouts[12] = {
>      AV_CH_LAYOUT_4POINT1, AV_CH_LAYOUT_5POINT1_BACK, 0,
>  };
>  
> -static int crc_init = 0;
>  #if CONFIG_SMALL
>  #define CRC_TABLE_SIZE 257
>  #else
> @@ -72,14 +72,17 @@ static AVCRC crc_63[CRC_TABLE_SIZE];
>  static AVCRC crc_1D[CRC_TABLE_SIZE];
>  static AVCRC crc_2D[CRC_TABLE_SIZE];
>  
> +static av_cold void mlp_init_crc(void)
> +{
> +    av_crc_init(crc_63, 0,  8,   0x63, sizeof(crc_63));
> +    av_crc_init(crc_1D, 0,  8,   0x1D, sizeof(crc_1D));
> +    av_crc_init(crc_2D, 0, 16, 0x002D, sizeof(crc_2D));
> +}
> +
>  av_cold void ff_mlp_init_crc(void)
>  {
> -    if (!crc_init) {
> -        av_crc_init(crc_63, 0,  8,   0x63, sizeof(crc_63));
> -        av_crc_init(crc_1D, 0,  8,   0x1D, sizeof(crc_1D));
> -        av_crc_init(crc_2D, 0, 16, 0x002D, sizeof(crc_2D));
> -        crc_init = 1;
> -    }
> +    static AVOnce init_static_once = AV_ONCE_INIT;
> +    ff_thread_once(&init_static_once, mlp_init_crc);
>  }
>  
>  uint16_t ff_mlp_checksum16(const uint8_t *buf, unsigned int buf_size)
> 
Will apply this patchset tomorrow unless there are objections.

- Andreas