async Client/Server app, accept() stalls?
First off, I am very inexperienced with network programming, but I thought I'd try my hand with asynchronous sockets. So, after reading some of this tutorial, I made a program that should be able to connect or wait for a connection. So I made a network class, and simply set it to connect to my local ip address if a button is pressed, or set to listen mode if the other button is pressed.
I can tell something is working, because I receive a FD_ACCEPT message on the instance I set to listen, but then my program never seems to reach any code after I call accept():
My window proc:
Member functions:Code:LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { switch (message) /* handle the messages */ { case WM_CREATE: CreateWindowEx(0, //more or 'extended' styles TEXT("BUTTON"), //'class' of control to create TEXT("Connect"), //the control caption WS_CHILD|WS_VISIBLE|BS_DEFPUSHBUTTON, //control style: how it looks 10, //control position: left 10, //control position: top 100, //control width 20, //control height hwnd, //parent window handle (HMENU)IDC_CONNECT, //control's ID g_hInst, //application instance NULL); CreateWindowEx(0, //more or 'extended' styles TEXT("BUTTON"), //'class' of control to create TEXT("Wait"), //the control caption WS_CHILD|WS_VISIBLE|BS_DEFPUSHBUTTON, //control style: how it looks 120, //control position: left 10, //control position: top 100, //control width 20, //control height hwnd, //parent window handle (HMENU)IDC_SERVER, //control's ID g_hInst, //application instance NULL); break; case WM_WSAASYNC: // what word? switch(WSAGETSELECTEVENT(lParam)) { case FD_ACCEPT: MessageBox(NULL,"Connection request received","Alert!",MB_OK); //this comes up // check for an error if (WSAGETSELECTERROR(lParam)) return(FALSE); // process message try { netwkobj.Accept(); } catch (const NetErr& error) { MessageBox(NULL,error.what(),"Network Error",MB_OK|MB_ICONEXCLAMATION); } return(0); break; case FD_READ: //receiving data break; case FD_WRITE: //.. break; case FD_CONNECT: //server got our connect message MessageBox(NULL,"Connect request accepted","Alert!",MB_OK); // this never comes up break; case FD_CLOSE: //connection closed PostQuitMessage(0); //just quit for now...i guess break; } break; case WM_COMMAND: switch(LOWORD(wParam)) { case IDC_CONNECT: //button pressed: try to connect to a server try { netwkobj.Init(hwnd,false); netwkobj.Connect("192.168.2.15"); } catch (const NetErr& error) { MessageBox(NULL,error.what(),"Network Error!",MB_OK|MB_ICONEXCLAMATION); } //MessageBox(NULL,"Connected","OK",MB_OK); break; case IDC_SERVER: try { netwkobj.Init(hwnd,true); //move this to when we try to join or host a game in a menu } catch (const NetErr& error) { MessageBox(NULL,error.what(),"Network Error!",MB_OK|MB_ICONEXCLAMATION); } // MessageBox(NULL,"Listening...","OK",MB_OK); break; } break; case WM_DESTROY: PostQuitMessage (0); /* send a WM_QUIT to the message queue */ break; default: /* for messages that we don't deal with */ return DefWindowProc (hwnd, message, wParam, lParam); } return 0; }
As I said, it seems to be working up to that point (I get a "could not connect" exception if I try to connect without setting another instance to wait, and if I set one to wait, when I click "connect" the other instance receives an FD_ACCEPT message)Code://network class member fcns Network::Network() { hSocket = INVALID_SOCKET; numclients=0; } void Network::Init(HWND hwnd, bool isserver) { init = true; WSADATA wsaData; if (WSAStartup(MAKEWORD(REQ_WINSOCK_VER,0), &wsaData)==0) //start winsock { // Check if major version is at least REQ_WINSOCK_VER if (LOBYTE(wsaData.wVersion) < REQ_WINSOCK_VER) { throw NetErr("Required Winsock Version not met!"); } } else throw NetErr("Error starting Winsock!"); // create and test the socket hSocket = socket(AF_INET, SOCK_STREAM, 0); if (hSocket == INVALID_SOCKET) throw NetErr("INVALID_SOCKET"); // make the socket asynchronous and notify of read, write, connect and close events // this is the client socket if (!isserver) { WSAAsyncSelect(hSocket, hwnd, WM_WSAASYNC, FD_WRITE | FD_CONNECT | FD_READ | FD_CLOSE); //set up asynchronous sockets //request WRITE, READ, CONNECT, and CLOSE messages be sent server=false; } // make the socket asynchronous and notify of read, write, accept and close events // this is the server socket else { //is this the right order? (set to listen before call to WSAAsyncSelect()? sockaddr_in sockAddr = {0}; SetServerSockAddr(&sockAddr, SERVER_PORT); if (bind(hSocket, reinterpret_cast<sockaddr*>(&sockAddr), sizeof(sockAddr))!=0) throw NetErr("Could not bind socket."); if (listen(hSocket, SOMAXCONN)!=0) //set socket to listen for incoming data throw NetErr("Could not put socket into listening mode."); WSAAsyncSelect(hSocket, hwnd, WM_WSAASYNC, FD_READ | FD_WRITE | FD_ACCEPT | FD_CLOSE); //again, async sockets server=true; } } void Network::Connect(const char* servIp) { if (!init) throw NetErr("Network not initialized!"); sockaddr_in sockAddr = {0}; FillSockAddrDot(&sockAddr, servIp, SERVER_PORT); if ((hSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == INVALID_SOCKET) throw NetErr("Could not create socket."); // Connect to server if (connect(hSocket, reinterpret_cast<sockaddr*>(&sockAddr), sizeof(sockAddr))!=0) throw NetErr("Could not connect."); } void Network::Accept() { if (!init) throw NetErr("Network not initialized!"); int clientSockSize = sizeof(client_addr); client_sock[0] = accept(hSocket,reinterpret_cast<sockaddr*>(&client_addr), &clientSockSize); //I never get an exception thrown, and if I put a messagebox here //it never comes up if (client_sock[numclients]==INVALID_SOCKET) throw NetErr("Could not accept incoming connection"); numclients++; }
Hopefully I'm just doing something stupid, since this is my first try with asynchronous sockets.
Edit: Boy, I feel stupid. I guess WSAGETSELECTERROR is telling me there's an error. Somehow I just glanced over that line. Should've put some kind of notification there. Now I just gotta figure out what the error means...
Edit2: MSDN doesn't have any error codes listed for the FD_ACCEPT message, and it returns error code 8...If I just continue like there's no problem, accept finished like there isn't a problem, but my client doesn't receive an FD_CONNECT message.
Edit3: Yes, another edit. Ok so now I realize that there aren't actually any error (stupid tutorial told me wrong) But I still don't receive a FD_CONNECT message...I think I'll take a break on this now...
