if (r & (POLLERR | POLLHUP)) {
if (r & POLLERR || r == POLLHUP) {
static void run_wconnection(struct connection *cn){	int n;	short r;	n = cn->pollno;	if (n == -1)		return;	r = pollfds[n].revents;	if (r & (POLLERR | POLLHUP)) {		close_connection(cn);		return;	}	if (r & POLLOUT)		write_connection(cn);}