add <sys/types.h>
@@ -55,6 +55,7 @@ int gettimeofday(struct timeval *tv, struct timezone *tz);
int settimeofday(const struct timeval *tv, const struct timezone *tz);
#ifdef RT_USING_PTHREADS
+#include <sys/types.h>
/* posix clock and timer */
#define MILLISECOND_PER_SECOND 1000UL
#define MICROSECOND_PER_SECOND 1000000UL
