Multi-threading with WinApi in C++

Question

I've been struggling with multi-threading for a while now...managed to work it out last night on my current program, what I wanted is to have a simple timer running while I'm still able to work with my application.

I used msdn reference .

I managed to make it work fine ( or at least I think it works fine ) with this code:

case ID_MENUBUTTON0:

        hRunMutex = CreateMutex(NULL, TRUE, NULL);
        _beginthread(Sistem::timeFrame, 0, NULL);
        break;

case ID_MENUBUTTON4:
        ReleaseMutex(hRunMutex);
        PostQuitMessage(0);
        break;

Sistem::timeFrame func calculates time with intervals of 100ms Sleep(100); and outputs it in a static window and updates the window every 100ms.

Now what I wanted to ask since I didn't really understand all the fuss about this is why is there so many extra stuff ? Such as WaitForSingleObject , I've seen a lot of it but can't figure out it's practical use. Is there something I should watch out for except for ReleaseMutex() ?

Answer 1

WaitForSingleObject and WaitForMultipleObjects are used to make a thread wait until another thread has done something. The practical use is coordination, like don't land the plane until the wheels are down.