1 files changed, 57 insertions, 0 deletions
diff --git a/vp8/common/rtcd.c b/vp8/common/rtcd.c
index 232640dc8..4980f48ad 100644
--- a/vp8/common/rtcd.c
+++ b/vp8/common/rtcd.c
@@ -10,3 +10,60 @@
 #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);
+}