diff options
| -rw-r--r-- | vp8/common/generic/systemdependent.c | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/vp8/common/generic/systemdependent.c b/vp8/common/generic/systemdependent.c index 39660abaa..2a3016618 100644 --- a/vp8/common/generic/systemdependent.c +++ b/vp8/common/generic/systemdependent.c @@ -82,6 +82,58 @@ static int get_cpu_count() } #endif + +#if HAVE_PTHREAD_H +#include <pthread.h> +static void once(void (*func)(void)) +{ + static pthread_once_t lock = PTHREAD_ONCE_INIT; + pthread_once(&lock, func); +} + + +#elif defined(_WIN32) +static void once(void (*func)(void)) +{ + /* Using a static initializer here rather than InitializeCriticalSection() + * since there's no race-free context in which to execute it. Protecting + * it with an atomic op like InterlockedCompareExchangePointer introduces + * an x86 dependency, and InitOnceExecuteOnce requires Vista. + */ + static CRITICAL_SECTION lock = {(void *)-1, -1, 0, 0, 0, 0}; + static int done; + + EnterCriticalSection(&lock); + + if (!done) + { + func(); + done = 1; + } + + LeaveCriticalSection(&lock); +} + + +#else +/* No-op version that performs no synchronization. vpx_rtcd() is idempotent, + * so as long as your platform provides atomic loads/stores of pointers + * no synchronization is strictly necessary. + */ + +static void once(void (*func)(void)) +{ + static int done; + + if(!done) + { + func(); + done = 1; + } +} +#endif + + void vp8_machine_specific_config(VP8_COMMON *ctx) { #if CONFIG_MULTITHREAD @@ -94,5 +146,5 @@ void vp8_machine_specific_config(VP8_COMMON *ctx) ctx->cpu_caps = x86_simd_caps(); #endif - vpx_rtcd(); + once(vpx_rtcd); } |