Asynchronuous Socket handling

Posted on 2001-06-30
Medium Priority
Last Modified: 2007-12-19
i am  working on an IRC Client...till now i am doing Synchronuous I/O...i mean for sending data i am using send() and for recieving data i am using recv() in a differnt thread...it is working all right but i want to change this to asynch stuff but cannt find any example...i want to handle send and recieve operations in a single thread Asynchronuously...any help will be greatly appreciated


Question by:newborn
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LVL 30

Expert Comment

ID: 6240371
What OS, What compiler, What type of project???

Author Comment

ID: 6240377
Compiler:VC++ 6.0
An IRC Client,TCP/IP protocol,stream sockets
LVL 30

Expert Comment

ID: 6240380
Is the project an MFC, Win32-App, or Win32-Console?
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Author Comment

ID: 6240382
Win32 app...as i said i am using send() and recv() API's no CSocket or ASyncSocket
LVL 32

Expert Comment

ID: 6240542
So what is your question?  If you're familiar with both blocking socket calls and with Windows message processing, you already understand this.  Rather than perform a network action when you call it the WINSOCK asynch calls queue the request and return to your app.  When the request completes (either sucessfully or with an error) your app will be sent a message about it.

I find that the best way to structure such a program is using a "state machine" to track the network operations as they progress.  This prevents having to have a separate message queue for each type of network event and therefore having to implement a bunch of global vars.
LVL 14

Expert Comment

ID: 6240551
see example of using asynchronously in
  Send Mail (socket 2) "Davide Libenzi"
LVL 14

Accepted Solution

AlexVirochovsky earned 200 total points
ID: 6261993
Next is snippet from Davide code:
int SvrConnectTimeout(SOCKET SockFD, const struct sockaddr * pSockName, int iNameLen,
                        int iTimeout)

    WSAEVENT        hConnectEvent;

    if ((hConnectEvent = WSACreateEvent()) == NULL)
        return (-1);

    WSAEventSelect(SockFD, hConnectEvent, FD_CONNECT);

    int iConnectResult = WSAConnect(SockFD, pSockName, iNameLen, NULL, NULL, NULL, NULL);

    int iConnectError = WSAGetLastError();

    if ((iConnectResult != 0) && (iConnectError == WSAEWOULDBLOCK))
        DWORD           dwWaitResult,
                        dwEntryCount = GetTickCount();

        while ((dwWaitResult = WSAWaitForMultipleEvents(1, &hConnectEvent, FALSE,
                                dwStepTimeout, TRUE)) != WSA_WAIT_EVENT_0)
            if (dwWaitResult == WSA_WAIT_FAILED)

            if ((iTimeout > 0) &&
                    ((iTimeout * 1000) < (int) (GetTickCount() - dwEntryCount)))

            if (CallIdleProc() < 0)
        iConnectResult = (dwWaitResult == WSA_WAIT_EVENT_0) ? 0 : -1;

    WSAEventSelect(SockFD, hConnectEvent, 0);

    return (iConnectResult);

Full project contens many such examples.
I hope, it helps. Alex

Author Comment

ID: 6262017
i have solved my prob ,www.sockets.com has very good samples i got my thing from wal,ur sample is also good,no need of window to recieve the call back notifications ,events can do, i will try to improve my code,many thanx for ur help

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