Shulou(Shulou.com)06/03 Report--

This article mainly introduces "how to use GCD in swift". In daily operation, I believe many people have doubts about how to use GCD in swift. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts about "how to use GCD in swift". Next, please follow the editor to study!

Grand Central Dispath (GCD)

GCD adopts the mode of task + queue, which is easy to use, high efficiency and good performance.

/ / concurrent parallel let queue = DispatchQueue (label: "myQueue", qos: DispatchQoS.default, attributes: DispatchQueue.Attributes.concurrent, autoreleaseFrequency: DispatchQueue.AutoreleaseFrequency.inherit Target: nil) / / syncqueue.sync {sleep (1) print ("in queue sync")} / / asyncqueue.async {sleep (1) print ("in queue async")} / / asyncAfterqueue.asyncAfter (deadline: .now () + 1) {print ("in queue asyncAfter")} print ("after invoke queue method") / * in queue sync after invoke queue method in queue async in queue asyncAfter * / DispatchGroup-wait//DispatchGroup-waitlet workingGroup = DispatchGroup () Let workingQueue = DispatchQueue (label: "request_queue") workingGroup.enter () workingQueue.async {sleep (1) print ("A done") workingGroup.leave ()} workingGroup.enter () workingQueue.async {print ("B done") workingGroup.leave ()} print ("first") / / workingGroup.wait () / / print ("last") / * first A done B done last * / DispatchGroup-notify//DispatchGroup-notifyworkingGroup.notify (queue: workingQueue) { Print ("An and B done")} print ("other") / * first other A done B done An and B done * / DispatchSource-Timer//DispatchSource-Timervar seconds = 10let timer: DispatchSourceTimer = DispatchSource.makeTimerSource (flags: [] Queue: DispatchQueue.global () timer.schedule (deadline: .now (), repeating: 1.0) timer.setEventHandler {seconds-= 1 if seconds

Int? {lock.lock () var temp: Int? = nil if array.count > 0 {temp = array [array.count-1]} lock.unlock () return temp} func removeLastItem () {lock.lock () array.removeLast () lock.unlock ()} queue.async {for _ in 0..

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.