ios-resource
- Thread and Concurencies ~ https://www.slideshare.net/Makeschool/multithreading-on-ios https://www.appcoda.com/grand-central-dispatch/ http://rx-marin.com/post/observeon-vs-subscribeon/ https://theswiftdev.com/2017/08/22/tasks-and-threads-in-swift/ https://developer.apple.com/library/archive/documentation/Performance/Conceptual/EnergyGuide-iOS/PrioritizeWorkWithQoS.html https://www.quora.com/Why-must-the-UI-always-be-updated-on-Main-Thread