t_listen
if (t_listen(fd, call) < 0) {
if (t_listen(fd, conn->conn_call) == -1) {
if (t_listen(fd, call) < 0) {
extern int t_listen(int, struct t_call *);
if (t_listen(xprt->xp_fd, r->t_call) == -1) {
if (t_listen(srcfd, tcp2) == -1) {
extern int t_listen(int fildes, struct t_call *call);