+#define RW_LOCK_READER_EVENT(x) ((event_t) (((unsigned char*) (x)) + (offsetof(lck_rw_t, lck_rw_tag))))
+#define RW_LOCK_WRITER_EVENT(x) ((event_t) (((unsigned char*) (x)) + (offsetof(lck_rw_t, lck_rw_pad8))))
+#define READ_EVENT_TO_RWLOCK(x) ((lck_rw_t *)(((unsigned char*)(x) - (offsetof(lck_rw_t, lck_rw_tag)))))
+#define WRITE_EVENT_TO_RWLOCK(x) ((lck_rw_t *)(((unsigned char*)(x) - (offsetof(lck_rw_t, lck_rw_pad8)))))
+