Why DispatchQueue.main.async is not performed?

Question

My app has finished to respond unexpectedly. I have researched and noticed that this operator is never performed (see picture). Why? queue is nil. I use Xcode 8.1. In point "come here" I'm on the thread 3. So any request is not performed.

Edit. Storyboard is loading at the same time. iOS can't load storyboard which I created in Xcode 7.3. Even it had been working for some time in Xcode 8. I don't know what happened and why it finished to work. I checked changes on git. They are absent. Probably I have to recreate my storyboard on Xcode 8.

Answer 1

Based on what you have shown, without the full context, I am guessing that the code is looping infinitely (hence increasing memory). Some code from main queue is making async call infinitely, triggering this 'response' function when the call finishes. The responses are dispatched to main but they are not executed because the main queue is hogged up making async calls.