Create thread is not accepting the member function

Question

I am trying to create a class for network programming. This will create a general purpose socket with thread.

But when I tried to crete the thread using createthread(). The third argument is producing errors. And from the net I came to know that I can't use the member functions as an argument to the createthread().

Is there any thing by which I can achieve this?

Answer 1

The easiest way to handle this is to create a "stub" function which calls back into your class.

UINT tid
HANDLE hThread = CreateThread(NULL, 0, myThreadStub, this, 0, &tid);

....

unsigned long WINAPI myThreadStub(void *ptr) 
{
    if (!ptr) return -1;
    return ((MyClass*)ptr)->ThreadMain();
}

CreateThread() allows you to pass an argument to the thread function (parameter 4 of the CreateThread() call). You can use this to pass a pointer to your class. You can then have the thread stub cast that pointer back into the proper type and then call a member function. You can even have "myThreadStub" be a static member of "MyClass", allowing it to access private members and data.

If you have boost installed, you may be able to use boost::bind to do this without creating a stub function. I've never tried that on windows, so I can't say for sure it would work (because the callback function must be a WINAPI call) but if it does work it would look something like:

HANDLE hThread = CreateThread(NULL, 0, boost::bind(&MyClass::ThreadFunction, this), NULL, 0, &tid);

Where thread function is a non-static member function which takes a single void * argument.