$pm->finish(0,\$scalar);  # or
$pm->finish(0,\@array);   # or
$pm->finish(0,\%hash);


##</code><code>##

$pm -> run_on_finish (
    sub {
        my ($pid, $exit_code, $ident, $exit_signal, $core_dump, $data_ref) = @_;

        if (defined($data_ref)) {
            my $scalar = ${$data_ref};  # or
            my @array  = @{$data_ref};  # or
            my %hash   = %{$data_ref};
        }
    }
);