void AsyncUDPSocket::init()

in folly/io/async/AsyncUDPSocket.cpp [99:225]

• 106 lines of code
• 20 McCabe index (conditional complexity)

void AsyncUDPSocket::init(sa_family_t family, BindOptions bindOptions) {
  NetworkSocket socket =
      netops::socket(family, SOCK_DGRAM, family != AF_UNIX ? IPPROTO_UDP : 0);
  if (socket == NetworkSocket()) {
    throw AsyncSocketException(
        AsyncSocketException::NOT_OPEN,
        "error creating async udp socket",
        errno);
  }

  auto g = folly::makeGuard([&] { netops::close(socket); });

  // put the socket in non-blocking mode
  int ret = netops::set_socket_non_blocking(socket);
  if (ret != 0) {
    throw AsyncSocketException(
        AsyncSocketException::NOT_OPEN,
        "failed to put socket in non-blocking mode",
        errno);
  }

  if (reuseAddr_) {
    // put the socket in reuse mode
    int value = 1;
    if (netops::setsockopt(
            socket, SOL_SOCKET, SO_REUSEADDR, &value, sizeof(value)) != 0) {
      throw AsyncSocketException(
          AsyncSocketException::NOT_OPEN,
          "failed to put socket in reuse mode",
          errno);
    }
  }

  if (reusePort_) {
    // put the socket in port reuse mode
    int value = 1;
    if (netops::setsockopt(
            socket, SOL_SOCKET, SO_REUSEPORT, &value, sizeof(value)) != 0) {
      throw AsyncSocketException(
          AsyncSocketException::NOT_OPEN,
          "failed to put socket in reuse_port mode",
          errno);
    }
  }

  if (freeBind_) {
    int optname = 0;
#if defined(IP_FREEBIND)
    optname = IP_FREEBIND;
#endif
    if (!optname) {
      throw AsyncSocketException(
          AsyncSocketException::NOT_OPEN, "IP_FREEBIND is not supported");
    }
    // put the socket in free bind mode
    int value = 1;
    if (netops::setsockopt(
            socket, IPPROTO_IP, optname, &value, sizeof(value)) != 0) {
      throw AsyncSocketException(
          AsyncSocketException::NOT_OPEN,
          "failed to put socket in free bind mode",
          errno);
    }
  }

  if (busyPollUs_ > 0) {
    int optname = 0;
#if defined(SO_BUSY_POLL)
    optname = SO_BUSY_POLL;
#endif
    if (!optname) {
      throw AsyncSocketException(
          AsyncSocketException::NOT_OPEN, "SO_BUSY_POLL is not supported");
    }
    // Set busy_poll time in microseconds on the socket.
    // It sets how long socket will be in busy_poll mode when no event occurs.
    int value = busyPollUs_;
    if (netops::setsockopt(
            socket, SOL_SOCKET, optname, &value, sizeof(value)) != 0) {
      throw AsyncSocketException(
          AsyncSocketException::NOT_OPEN,
          "failed to set SO_BUSY_POLL on the socket",
          errno);
    }
  }

  if (rcvBuf_ > 0) {
    // Set the size of the buffer for the received messages in rx_queues.
    int value = rcvBuf_;
    if (netops::setsockopt(
            socket, SOL_SOCKET, SO_RCVBUF, &value, sizeof(value)) != 0) {
      throw AsyncSocketException(
          AsyncSocketException::NOT_OPEN,
          "failed to set SO_RCVBUF on the socket",
          errno);
    }
  }

  if (sndBuf_ > 0) {
    // Set the size of the buffer for the sent messages in tx_queues.
    int value = sndBuf_;
    if (netops::setsockopt(
            socket, SOL_SOCKET, SO_SNDBUF, &value, sizeof(value)) != 0) {
      throw AsyncSocketException(
          AsyncSocketException::NOT_OPEN,
          "failed to set SO_SNDBUF on the socket",
          errno);
    }
  }

  if (family == AF_INET6) {
    int flag = static_cast<int>(bindOptions.bindV6Only);
    if (netops::setsockopt(
            socket, IPPROTO_IPV6, IPV6_V6ONLY, &flag, sizeof(flag))) {
      throw AsyncSocketException(
          AsyncSocketException::NOT_OPEN, "Failed to set IPV6_V6ONLY", errno);
    }
  }

  // success
  g.dismiss();
  fd_ = socket;
  ownership_ = FDOwnership::OWNS;

  // attach to EventHandler
  EventHandler::changeHandlerFD(fd_);
}