SBL_NOINTR
error = SOCK_IO_SEND_LOCK(so, SBL_WAIT | SBL_NOINTR);
error = SOCK_IO_RECV_LOCK(so, SBL_WAIT | SBL_NOINTR);
if ((flags & SBL_NOINTR) != 0) {
error = SOCK_IO_SEND_LOCK(so_dst, SBL_WAIT | SBL_NOINTR);
error = SOCK_IO_RECV_LOCK(so_src, SBL_WAIT | SBL_NOINTR);
error = SOCK_IO_RECV_LOCK(so, SBL_WAIT | SBL_NOINTR);
#define SBL_VALID (SBL_WAIT | SBL_NOINTR)