#!/usr/bin/perl
use strict;
use warnings;
use threads;
use threads::shared;
use Tk;

my $count:shared=0;
my $thread = threads->new( \&launch_thread )->detach;

my $mw = MainWindow->new();
$mw->geometry("600x400+100+100");

my $l1 = $mw->Label(-textvariable => \$count)->pack();

MainLoop;

sub launch_thread {

   while (1){
       $count++;
       print "$count\n";
       sleep 1;
     }
}