Message loop question.

As far as I know the GetMessage() function returns zero if it receives a WM_QUIT message. This is often used as a way to stop the message loop and terminate the program. Since I like to play around with my code to see the actual effects of API functions and how they could be used I tried to remove my PostQuitMessage() function just to see if the program remains in memory after the main window is destroyed. I noticed it quits completely, and I want to know why just for the sake of knowing
I really appreciate all help I can get.

Here is my message loop

Code:

while(GetMessage(&msg, WndPtr, 0, 0) > 0)
{
	TranslateMessage(&msg);
	DispatchMessage(&msg);
}

and here's my WndProc

Code:

LRESULT CALLBACK msg_control(HWND WndPtr, unsigned int msg, WPARAM wParam, LPARAM lParam)
{
	if (msg == WM_CLOSE)
	{
		DestroyWindow(WndPtr);
	}
	else if(msg == WM_DESTROY)
	{
		//PostQuitMessage(0);
	}
	else
	{
		return DefWindowProc(WndPtr, msg, wParam, lParam);
	}
	return 0;
}

Your window might have vanished from sight and been destroyed but your message loop is still spinning contentedly away - ie., your program is still running. To confirm this, check it with the task manager.

The thing is, I have checked the taskmanager and it confirms that the entire process is terminated when I destroy the window. I can't understand why the loop quits.

When window is destroyed GetMessage called with its hwnd as a param returns -1 indicating error.

Code:

while(GetMessage(&msg, WndPtr, 0, 0) > 0)

A message loop should use NULL as the second argument to GetMessage. As vart pointed out, your message loop relies on an error to exit. The WM_QUIT will never be received as it is sent to the thread and not a specific window.

Doh!

One of these days I might just actually start looking at the code before leaping to an erroneous conclusion.

Sorry, antex - fortunately both vart and 'tmouse were paying attention to your supplied code; please ignore my earlier assertion which did not take into account the code you were actually using.

Ah okey, thank you all very much for replying, this saved me from (more) confusion.