ios 앱 개발 오늘하루 swift uiview NSLock Run Loop Thread-safe UIKit defer atomic operations CAAnimation CADisplayLink event chain UIEvent App Store Connect KDCircularProgress 스위프트5 main thread swift5 SwiftyJSON alamofire firebase CoreLocation cocoapods Autolayout 엑스코드 CGRect CGSize CGPoint UIApplication thread safe 싱글톤 패턴 앱 framerate multi-thread storyboard Xcode 미세먼지 Lazy 스위프트 archive 아카이브 지연 위치정보 멈춤 Thread layout 개발