#!/usr/bin/perl

use warnings;
use strict;
use threads;
use threads::shared;
use Data::Dumper;

my %hash :shared;

sub sub1 {
  sleep 1;
  print threads->tid();
  print Dumper \%hash;
}

$hash{a} = &share({});

my $th1 = threads->new('sub1');
$hash{b} = &share({});
my $th2 = threads->new('sub1');

$th1->join();
$th2->join();
__OUTPUTS__
C:\test>junk1
1$VAR1 = {
          'a' => {},
          'b' => {}
        };

2$VAR1 = {
          'a' => {},
          'b' => {}
        };