initial check-in, version 0.5.0

src/thread/pthread_rwlock_rdlock.c

@@ -0,0 +1,8 @@
+#include "pthread_impl.h"
+
+int pthread_rwlock_rdlock(pthread_rwlock_t *rw)
+{
+	while (pthread_rwlock_tryrdlock(rw))
+		__wait(&rw->__wrlock, &rw->__waiters, 1, 0);
+	return 0;
+}