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Diffstat (limited to 'vp8/common/rtcd.c')
-rw-r--r-- | vp8/common/rtcd.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/vp8/common/rtcd.c b/vp8/common/rtcd.c new file mode 100644 index 000000000..4980f48ad --- /dev/null +++ b/vp8/common/rtcd.c @@ -0,0 +1,69 @@ +/* + * Copyright (c) 2011 The WebM project authors. All Rights Reserved. + * + * Use of this source code is governed by a BSD-style license + * that can be found in the LICENSE file in the root of the source + * tree. An additional intellectual property rights grant can be found + * in the file PATENTS. All contributing project authors may + * be found in the AUTHORS file in the root of the source tree. + */ +#include "vpx_config.h" +#define RTCD_C +#include "vpx_rtcd.h" + +#if CONFIG_MULTITHREAD && 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 CONFIG_MULTITHREAD && defined(_WIN32) +#include <windows.h> +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 vpx_rtcd() +{ + once(setup_rtcd_internal); +} |