my $r = shift;
   [...]
   my $time = time;
   if ($session->{LAST_REQUEST} >= $time - 1) {
      $r->connection->keepalive(Apache2::Const::CONN_CLOSE);
      ModPerl::Util::exit(0);
   }
   else {
      $session->{LAST_REQUEST} = $time;
   }
   [...]