Thread: Create a blocked/unblocked socket?

  1. #1
    Registered User
    Join Date
    Sep 2004

    Create a blocked/unblocked socket?

    How does one create a blocked socket?
    How does one create an unblocked socket?
    Where is the Win API documentation for this?
    Thank you.

    Here is the standard generic code for creating a socket.

    The generic code:
    //gcc e1.c -lws2_32 -o e1.exe
    #include <windows.h>
    #include <stdio.h>
    #include <winsock.h>
    #define PORT (u_short) 44444
    #define DEST_IP_ADDR ""
    int main()
      WSADATA Data;
      SOCKADDR_IN destSockAddr;
      SOCKET destSocket;
      unsigned long destAddr;
      int status;
      status = WSAStartup(MAKEWORD(1, 1), &Data);
      if (status != 0)
        { printf("WSAStartup unsuccessful\n"); }
      destAddr = inet_addr(DEST_IP_ADDR);
      memcpy(&destSockAddr.sin_addr, &destAddr, sizeof(destAddr));
      destSockAddr.sin_port = htons(PORT);
      destSockAddr.sin_family = AF_INET;
      destSocket = socket(AF_INET, SOCK_STREAM, 0);
      if (destSocket == INVALID_SOCKET) {
        printf("socket unsuccessful\n");
      printf("socket created.\n");
    Thanks for any help.

  2. #2
    Registered User
    Join Date
    Sep 2004
    I found this:
    // Set the socket I/O mode: In this case FIONBIO
    // enables or disables the blocking mode for the 
    // socket based on the numerical value of iMode.
    // If iMode = 0, blocking is enabled; 
    // If iMode != 0, non-blocking mode is enabled.
    int iMode = 0;
    ioctlsocket(m_socket, FIONBIO, (u_long FAR*) &iMode);

  3. #3
    Registered User
    Join Date
    Sep 2004
    That's how it's done. Sockets are blocking by default until you change them with ioctlsocket. Another option you have which I find easier to work with than nonblocking sockets is asynchronous sockets. Read the MSDN documentation for WSAAsyncSelect for more information on that.

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