+ memset(&act, 0, sizeof(act));
+ ret = sigemptyset(&act.sa_mask);
+ if (ret == -1) {
+ perror("sigemptyset");
+ return -1;
+ }
+ act.sa_handler = sigusr1_handler;
+ act.sa_flags = SA_RESTART;
+ ret = sigaction(SIGUSR1, &act, NULL);
+ if (ret == -1) {
+ perror("sigaction");
+ return -1;
+ }
+