#!/usr/local/bin/perl -w
use Tk;
use strict;
use vars qw( $mw );
use vars qw( $b_array);
use Data::Dumper;
use threads;
use threads::shared;

my @array = ();
 
threads->new(\&mysub);
 
$mw = MainWindow->new( -relief => 'flat' );
$mw->geometry('50x50+50+50');

$b_array = $mw->Button( -pady => '1', -relief => 'sunken', -padx => '1', -state => 'normal', -justify => 'center', -text => 'Array', -command => \&button_pressed )->place( -x => 25, -y => 25);

#&UpdateArray("YES"); #=> from here is OK when button_pressed
 
MainLoop();
	
sub button_pressed { 
    print Dumper(\@array);
}

sub UpdateArray {
	my $data = $_[0];
	
	my $j = 0;
	for (my $i=0; $i<length($_[0]);$i=$i+1){
	   $array[$i][$j]= $data;
	   $j++;
	}	
    print Dumper(\@array);
}

sub mysub {
    &UpdateArray("NO"); #=> array is empty when button_pressed
}