#!/usr/bin/perl
use warnings;
use strict;

use threads;
use threads::shared;
use Data::Dumper;

sub test {

#     my %h ; shared;  #dosn't work
       our %h : shared;   #works

    for (1 .. 3) {
        threads->create(sub {
                            my $n = shift;
                            lock %h;
                            $h{$n} = rand;
                        }, $_)->join;
    }
    return %h;
}

print Dumper {test()};