windowswinapitimerresource-leak

Is KillTimer necessary?

I use SetTimer API and I see a lot of code like this:

case WM_DESTROY: 
    // Destroy the timer. 
    KillTimer(hwnd, IDT_TIMER); 
    PostQuitMessage(0); 
    break;

Do I have to call KillTimer or the system will automatically free resources on the process exit? Does forgetting to call KillTimer lead to resource leaks?

I understand that if the timer is not needed it CAN be destroyed by KillTimer. But MUST it be destroyed manually?

Solution

  • Timers set from HWNDs are implicitly destroyed by the window (hwnd) being destroyed. So no, you don't have to clean up your timers when the window exits.

    But it's a good practice to have all your resources related to the window cleaned up on window close.