if you are trying to make alarm clock then you need a call back function for extra module. try to make a script that rotate the functions and check for its timeout. Again if you are trying to do something after reporting timeout.

my $time_out = 5;
my $flag = 1;
while(1){
    my $diff = time() - $starttime;
    if($diff >= $time_out){
        print "already reached maximum timeout\n";
        last;
    }
    if($flag){
        printData();
        $flag = 0;
    }
    sleep(1);
}
sub printData {
    print "i am running....\n";
}
[download]