如何在不使用C ++ 11线程的情况下使用functor作为线程函数在Windows中开始线程？

Question

I'm writing a simple thread lib for Windows. I want to pass this functor

struct callable
{
    void operator()()
    {
        for(int i = 0; ;++i)
        {
            std::cout << i << std::endl;
        }
    }
};

In _beginthread() this way:

int main()
{  
    callable c;
    _beginthread(c, 0, 0);
}

but it's not possible. The ability to pass functor in the thread is very necessary for my library. I know that boost::thread provides this ability, thus it is possible. How can I begin thread in windows using functor as thread function without using C++11 thread?

[upd] without using C++11 thread

Answer 1

The standard technique is as follows:

• Define a struct to hold whatever information you need to pass to the thread. In your case that information is the callable functor. So, you already have a suitable struct at hand.
• Allocate one of these structs on the heap. This happens in the calling thread, but the information is passed to the created thread which is why it cannot live on the stack.
• Call CreateThread passing a suitable thread proc (more later), and the address of your struct in the lpParameter parameter.
• In the thread proc, you are passed the address of the struct in lpParameter .
• Cast that pointer to the appropriate type and call your functor.
• Delete the heap allocated memory.

The thread proc looks like this:

DWORD WINAPI ThreadProc(void *lpParameter)
{
    callable *c = (callable*)lpParameter;
    (*c)();
    delete c;
    return 0;
}

And the call to CreateThread is along these lines:

callable *c = new callable;
// initialise c
CreateThread(NULL, 0, ThreadProc, (void*)c, 0, &threadID);

I apologise if there are syntax errors here, I'm not at all fluent in C++.