use Thread::Semaphore;
my $todosem = new Thread::Semaphore;
my @TodoList;
...
my $temp = Thread->new(\&Monitor);

$todosem->down;
$TodoList[0][7] = "running";
$todosem->up;

foreach $thread (Thread->list) {
    while(1){#wait for a thread to be finished
        foreach $thread (Thread->list) {
            $bool = $thread->done; #thread is done?
            last if ($bool);# if $bool true exit foreach
        }
        last if ($bool);# if $bool true exit while
    }
    $thread->join();# join this Workerthread
}  



sub Monitor(){
my $arraysize = @TodoList;
  
while (1) {
$todosem->down;
  for(my $i=0; $i < $arraysize; $i++){
     print $TodoList[$i][7];
      }
  $todosem->up;  
  sleep 5;
}  
}