Application hangs inside a Qt function

Question

At one point in the execution of our app, the app looks frozen and stops responding for about 40 seconds. After that it does exactly one thing (like moving the window app) and it's frozen again.

After a bit of investigation, I found what Qt function was causing the problem but I am not sure why. The question is why does the Qt function (which can be seen in the image below) causing so much trouble or could it help me to find the real culprit?

Answer 1

Looks like an event that triggers it self in and endless loop. I had similar problems with calling qwidget->update() or qwidget->repaint() manually.