37     sigset_t mask;  in main()  local
43     sigemptyset (&mask);  in main()
44     sigaddset (&mask, SIGUSR1);  in main()
45     fd = signalfd (-1, &mask, 0);  in main()
46     sigaddset (&mask, SIGUSR2);  in main()
47     fd = signalfd (fd, &mask, 0);  in main()
54     ppoll (pfd, 2, &ts, &mask);  in main()
72     sigset_t mask;  in main()  local
74     sigemptyset (&mask);  in main()
75     sigaddset (&mask, SIGUSR1);  in main()
76     sigaddset (&mask, SIGUSR2);  in main()
78     epoll_pwait (fd3, evs, 10, 0, &mask);  in main()