void send(void *buf, int count, int dest, int tag, $comm comm) {
    $message out = $message_pack(rank, dest, tag, buf, count*sizeof(double));
    $comm_enqueue(comm, out);
  }

  void recv(void *buf, int count, int source, int tag, $comm comm) {
    $message in = $comm_dequeue(comm, source, tag);
    $message_unpack(in, buf, count*sizeof(double));
  }

  $when (__start);