sub in_sub_process {

  my ($self, $code) = @_;

  my $rand = rand();

  my $file = ".tmp.$$.$rand.answer";

use Storable;

  my $cpid = fork;

  if ($cpid) {

      wait;

      open (my $fh, $file);

      my $data = do { local $/; <$fh> };

      my $res = eval { Storable::thaw($data); };

      unlink $file;

      return $res;

  }

  my $res = $code->();

  if (open (my $fh, ">$file.writing")) {

      print $fh Storable::nfreeze($res);

      CORE::close($fh);

      rename "$file.writing", $file;

      exit 0;

  }

}

sub parse_rules {

  my ($self, $str) = @_;

  my @wanted = qw( errors descriptions test_types scoreset

    scoreset_current tflags body_tests uri_tests uri_evals head_tests

    head_evals body_evals full_tests full_evals rawbody_tests rawbody_evals

    meta_tests regression_tests rewrite_header user_rules_to_compile

    user_defined_rules headers_spam headers_ham bayes_ignore_headers

    bayes_ignore_from bayes_ignore_to whitelist_from whitelist_allows_relays

    blacklist_from blacklist_to whitelist_to more_spam_to all_spam_to

    trusted_networks internal_networks headers_spam headers_ham

    num_check_received bayes_expiry_pct bayes_expiry_period

    bayes_expiry_max_exponent encapsulated_content_description);

  my $back = $self->{main}->in_sub_process(sub {

    $self->{parser}->parse ($str, 0);

    my %back = ();

    foreach my $want (@wanted) { $back{$want} = $self->{$want}; }

    warn "read config in subprocess";

    return \%back;

  });

  foreach my $want (@wanted) { $self->{$want} = $back->{$want}; }

}