foreach my $node_name (@nodes) {
    my $port_hashref = Mod1->sub1($node_name);
    my $pid = fork;
    die "Unable to fork: $!\n" unless defined $pid;
    unless ($pid) {
        # Child process.
        Mod2->sub2($node_name, $port_hashref);
        exit;  # When done, child should terminate.
    }
}
1 while -1 != wait;  # Reap children.