1: let queue = DispatchQueue.global(qos:DispatchQoS.QoSClass.default)
queue.async{
self.perform(#selector(self.printRunLoopStop),with:nil,afterDelay:1)
RunLoop.current.run()
}
@objc func printRunLoopStop(){
print("p r i n t ")
}
2:1111 1111 = 1 1 1 1 0 0 0 0 (|) 0 0 0 0 1 1 1 1
