SOCK_IO_SEND_LOCK
error = SOCK_IO_SEND_LOCK(so, SBL_WAIT);
while (SOCK_IO_SEND_LOCK(so, 0) == EWOULDBLOCK) {
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
error = SOCK_IO_SEND_LOCK(so, SBL_WAIT | SBL_NOINTR);
error = SOCK_IO_SEND_LOCK(so, SBL_WAIT);
error = SOCK_IO_SEND_LOCK(so, SBL_WAIT);
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
error = SOCK_IO_SEND_LOCK(so_dst, SBL_WAIT | SBL_NOINTR);
error = SOCK_IO_SEND_LOCK(so_dst, 0);
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));
error = SOCK_IO_SEND_LOCK(so, SBLOCKWAIT(flags));