Using QWidget::update() from non-GUI thread

Question

Sometimes my application crashes in QWidget::update() that is performing in non-GUI thread.

I am developing an application in which receives video frames from remote

Answer 1

Check out the Mandelbrot Example. In that example a worker thread is generating an image and passing it to rendering widget with signal/slot mechanism. Use the same method!

Instead of implementing a new updatePixmap() slot as given in the example you can directly connect update () slot of your widget as well.

From your code I can see that you have a mutex to provide concurrent access. So it should be easy to directly use your update slot.

Both methods still use signal/slot mechanism because GUI operations outside the main thread are not allowed in Qt.