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| author | Michael Niedermayer <michaelni@gmx.at> | 2013-12-06 15:24:10 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2013-12-06 15:27:36 +0100 |
| commit | 133fbfc7811ffae7b97dd129fcd0b5e646742362 (patch) | |
| tree | 9114fed08d3d1b9b801e702b25a40a1e1df47c8b /libavcodec | |
| parent | 2b215f39391c0f9ddb547d16d568776e9e5da54d (diff) | |
| download | ffmpeg-133fbfc7811ffae7b97dd129fcd0b5e646742362.tar.gz | |
do O(1) instead of O(n) atomic operations in register functions
about 1ms faster startup time
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavcodec')
| -rw-r--r-- | libavcodec/utils.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/libavcodec/utils.c b/libavcodec/utils.c index 0397d3b68d..102a0490b0 100644 --- a/libavcodec/utils.c +++ b/libavcodec/utils.c @@ -206,7 +206,8 @@ av_cold void avcodec_register(AVCodec *codec) avcodec_init(); p = &first_avcodec; codec->next = NULL; - while(avpriv_atomic_ptr_cas((void * volatile *)p, NULL, codec)) + + while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, codec)) p = &(*p)->next; if (codec->init_static_data) @@ -3191,7 +3192,7 @@ void av_register_hwaccel(AVHWAccel *hwaccel) { AVHWAccel **p = &first_hwaccel; hwaccel->next = NULL; - while(avpriv_atomic_ptr_cas((void * volatile *)p, NULL, hwaccel)) + while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, hwaccel)) p = &(*p)->next; } |