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

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

my $watch = Tie::Watch->new(
   -variable => \$count,
#   -debug    => 1,
   -fetch    => \&fetch,
   -store    => \&store,
   -destroy  => sub {print "Final value=$count.\n"},
);


while(1){}


sub launch_thread {

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


sub store {
   print "changed\n";
}

sub fetch{
   print "fetched @_\n";

}