In iOS, is there a relationship between run loop and display refresh?

Question

In iOS, is there a relationship between run loop and display refresh? If so how?

Answer 1

Apple has a very good WWDC 2012 video describing in detail what happens at the end of each run loop when the current CATransaction commits and drawing happens and animations begin. You might also enjoy reading the less technical explanation of the "redraw moment" in my book:

http://www.apeth.com/iOSBook/ch17.html#_drawing_animation_and_threading