*/
  public int gen_lists (int range) {
    int ret;
    RequestOutputStream o = display.out;
    synchronized (o) {
      o.begin_request (glx.major_opcode, 104, 3);
      o.write_int32 (tag);
      o.write_int32 (range);
      ResponseInputStream i = display.in;
      synchronized (i) {
        i.read_reply (o);
        i.skip (8);
        ret = i.read_int32 ();
        i.skip (20);
      }
    }
    return ret;
  }