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| author | Michael Niedermayer <michaelni@gmx.at> | 2013-12-06 15:24:10 +0100 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2014-01-07 03:05:30 +0100 |
| commit | cf6cf50ac689e3dc69c54b66495cd4951105bf61 (patch) | |
| tree | f74fbcc6edaaef19e33f389de799dc5f9f757af5 | |
| parent | 1ecd1b4aeeb419fda0320458207991b95b4da543 (diff) | |
| download | ffmpeg-cf6cf50ac689e3dc69c54b66495cd4951105bf61.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>
(cherry picked from commit 133fbfc7811ffae7b97dd129fcd0b5e646742362)
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
| -rw-r--r-- | libavcodec/utils.c | 5 | ||||
| -rw-r--r-- | libavfilter/avfilter.c | 2 | ||||
| -rw-r--r-- | libavformat/format.c | 4 |
3 files changed, 6 insertions, 5 deletions
diff --git a/libavcodec/utils.c b/libavcodec/utils.c index ae32a35b87..554b30edbf 100644 --- a/libavcodec/utils.c +++ b/libavcodec/utils.c @@ -218,7 +218,8 @@ 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) @@ -3182,7 +3183,7 @@ 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; } diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c index f31968f394..c9c8accc2a 100644 --- a/libavfilter/avfilter.c +++ b/libavfilter/avfilter.c @@ -487,7 +487,7 @@ int avfilter_register(AVFilter *filter) filter->next = NULL; - while(avpriv_atomic_ptr_cas((void * volatile *)f, NULL, filter)) + while(*f || avpriv_atomic_ptr_cas((void * volatile *)f, NULL, filter)) f = &(*f)->next; return 0; diff --git a/libavformat/format.c b/libavformat/format.c index ac9100b604..36c0131c12 100644 --- a/libavformat/format.c +++ b/libavformat/format.c @@ -54,7 +54,7 @@ void av_register_input_format(AVInputFormat *format) AVInputFormat **p = &first_iformat; format->next = NULL; - while(avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format)) + while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format)) p = &(*p)->next; } @@ -63,7 +63,7 @@ void av_register_output_format(AVOutputFormat *format) AVOutputFormat **p = &first_oformat; format->next = NULL; - while(avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format)) + while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format)) p = &(*p)->next; } |