Can you tell me how to use eval on this code?

To achieve what?

How can I restart thread a thread if it died with same thread Id?

You cannot. Thread ids are allocated by the system and are not re-used.

If you need a number within your threads that you assign, just pass it in as a parameter:

for my number (0 ..3))
{
    my $thr = threads->create (
                sub {
                   my $numberPassedIn = shift;
                   worker();
                    }, $number                
                 )->detach();
}
[download]