netReceiveDatagram function net

bool netReceiveDatagram(Pointer<NetDatagramSocket> sock, Pointer<Pointer<NetDatagram>> dgram)

Receive a new packet that a remote system sent to a datagram socket.

Datagram sockets send packets of data. They either arrive as complete packets or they don't arrive at all, so you'll never receive half a packet.

This call never blocks; if no new data isn't available at the time of the call, it returns true immediately. The caller can try again later.

On a successful call to this function, it returns true, even if no new packets are available, so you should check for a successful return and a non-NULL value in *dgram to decide if a new packet is available.

You must pass received packets to NET_DestroyDatagram when you are done with them. If you want to save the sender's address past this time, it is safe to call NET_RefAddress() on the address and hold onto the pointer, so long as you call NET_UnrefAddress() on it when you are done with it.

Since datagrams can arrive from any address or port on the network without prior warning, this information is available in the NET_Datagram object that is provided by this function, and this is the only way to know who to reply to. Even if you aren't acting as a "server," packets can still arrive at your socket if someone sends one.

If there's a fatal error, this function will return false. Datagram sockets generally won't report failures, because there is no state like a "connection" to fail at this level, but may report failure for unrecoverable system-level conditions; once a datagram socket fails, you should assume it is no longer usable and should destroy it with SDL_DestroyDatagramSocket().

\param sock the datagram socket to send data through. \param dgram a pointer to the datagram packet pointer. \returns true if data sent or queued for transmission, false on failure; call SDL_GetError() for details.

\threadsafety You should not operate on the same socket from multiple threads at the same time without supplying a serialization mechanism. However, different threads may access different sockets at the same time without problems.

\since This function is available since SDL_net 3.0.0.

\sa NET_SendDatagram \sa NET_DestroyDatagram

extern SDL_DECLSPEC bool SDLCALL NET_ReceiveDatagram(NET_DatagramSocket *sock, NET_Datagram **dgram)

Implementation

bool netReceiveDatagram(
  Pointer<NetDatagramSocket> sock,
  Pointer<Pointer<NetDatagram>> dgram,
) {
  final netReceiveDatagramLookupFunction = _libNet
      .lookupFunction<
        Uint8 Function(
          Pointer<NetDatagramSocket> sock,
          Pointer<Pointer<NetDatagram>> dgram,
        ),
        int Function(
          Pointer<NetDatagramSocket> sock,
          Pointer<Pointer<NetDatagram>> dgram,
        )
      >('NET_ReceiveDatagram');
  return netReceiveDatagramLookupFunction(sock, dgram) == 1;
}