Wait Until Event Occurs

Question

Hey, I'm doing sockets programming. Pretty much new to it.

The application is a Windows Service, in its ServiceMain() function I call CAsyncSocket's Listen() method, to listen for client connections. But after it starts listening for connections, it'll return and the ServiceMain() function will return and the service is stopped.

What I want to do with this is that, wait until a specific event occurs say WM_QUIT, till than listen for connections. How to do it?

// static member function (callback)
void CNTService::ServiceMain(DWORD dwArgc, LPTSTR* lpszArgv)
{
    // m_Server containts two sockets
    // one for listening and one for accepting connections

    m_Server.StartListening(); // calls Listen method on the listener socket

    // it will return and service will quit
    // which I don't want
}

I'm okay with mixing Win32 and MFC, so if it can be done in Win32 please do tell me too :)

Answer 1

In a service you normally would use WaitForMultipleObjects and wait for whatever things your service does (WSAEventSelect for sockets when not using a framework) + a quit event that you signal when the service manager tells you to quit

Answer 2

The correct way to handle a socket server is something like (pseudo code with winsock) :

bind(listenerSocket);

while(!stopped)
{
     listen(listenerSocket);
     clientSocket = accept(listenerSocket);

     process(clientSocket);
}

The listen call is blocking, waiting for connection. This way you can handle multiple connections. the process method usually spawn a thread in a threadpool.

I'm not familliar with MFC sockets but you have the equivalent things in a more OO way. There is many tutorials about this sort of things. You can also use a library handling sockets (you gain portability ...) like boost.

If you only need to handle a connection and do some process, you only do :

bind(listenerSocket);

listen(listenerSocket);
clientSocket = accept(listenerSocket);

process(clientSocket);