use Event; 

Event->signal(signal=>'HUP', cb=>sub {$i++; kill 1, $$});
Event->signal(signal=>'ALRM', cb=>sub {printf "%d\t%d\n", ++$t, $i-$old_i; $old_i=$i; ; alarm 1}); 

alarm 1; kill 1, $$; 
Event::loop;