33     sigset_t sset;  in foo()  local
43     sigemptyset(&sset);  in foo()
44     sigaddset(&sset, SIGUSR2);  in foo()
45     sigprocmask(SIG_UNBLOCK, &sset, NULL);  in foo()
63     sigset_t sset;  in main()  local
65     sigemptyset(&sset);  in main()
66     sigaddset(&sset, SIGUSR1);  in main()
67     sigaddset(&sset, SIGUSR2);  in main()
68     sigprocmask(SIG_SETMASK, &sset, NULL);  in main()
78         sigprocmask(SIG_SETMASK, NULL, &sset);  in main()
79         ret = sigismember(&sset, SIGUSR2)? 0 : -1;  in main()