int xsend(void *socket, size_t size, void *data, int flags) {
  zmq_msg_t request;
  int code;

  zmq_msg_init_size(&request, size);
  memcpy(zmq_msg_data(&request), data, size);
  code = zmq_send(socket, &request, flags);
  zmq_msg_close(&request);

  return code;
}