grand-central-dispatch

问题 In a library that may be built with an iOS 5.x/OS X 10.7 deployment target or with a newer one I had a problem for properly defining a dispatch_queue_t property. For the most part I could solve it as suggested here: #if OS_OBJECT_HAVE_OBJC_SUPPORT // == 1 not really needed @property (nonatomic, strong) dispatch_queue_t loggerQueue; // An Objective-C object #else @property (nonatomic, assign) dispatch_queue_t loggerQueue; // A C pointer #endif This works when manually creating a static library

问题 I am using libDispatch (GCD) opensource on Android platform. So, most of the complex time consuming tasks are being done through NDK (where i am using libDispatch). For some calls, I am using dispatch_async(get_main_queue)...This is where the problem is coming... I am able to run tasks in the concurrent queues but not on main queue. Since this requires dispatch_main() to be called which we cannot do on here as Java thread will be blocked in that case. So, is it possible to run the Java UI on

问题 I know you might find this an odd question, but I'm just learning GCD and I want to fully understand all its aspects. So here it is: Is there ever any reason to dispatch a task SYNC on the CURRENT QUEUE? For example: dispatch_queue_t concurrentQueue = dispatch_get_global_queue(...); dispatch_async(concurrentQueue, ^{ //this is work task 0 //first do something here, then suddenly: dispatch_sync(concurrentQueue, ^{ //work task 1 }); //continue work task 0 }); I understand one thing: if instead

问题 I created this basic architecture to handle my networking stuff, i wanted to keep it modular and structured: public class NetworkManager { public private(set) var queue: DispatchQueue = DispatchQueue(label: "com.example.app.dispatchgroups", attributes: .concurrent, target: .main) public private(set) var dispatchGroup: DispatchGroup = DispatchGroup() private static var sharedNetworkManager: NetworkManager = { let networkManager = NetworkManager() return networkManager }() private init() {}

问题 I created this basic architecture to handle my networking stuff, i wanted to keep it modular and structured: public class NetworkManager { public private(set) var queue: DispatchQueue = DispatchQueue(label: "com.example.app.dispatchgroups", attributes: .concurrent, target: .main) public private(set) var dispatchGroup: DispatchGroup = DispatchGroup() private static var sharedNetworkManager: NetworkManager = { let networkManager = NetworkManager() return networkManager }() private init() {}

问题 I'm having a hard time finding good examples on how to use these functions. static void * kQueue1Key = "key1"; static void * kQueue2Key = "key2"; dispatch_queue_t queue1 = dispatch_queue_create("com.company.queue1", DISPATCH_QUEUE_SERIAL); dispatch_queue_t queue2 = dispatch_queue_create("com.company.queue2", DISPATCH_QUEUE_SERIAL); dispatch_queue_set_specific(queue1, kQueue1Key, (void *)kQueue1Key, NULL); dispatch_queue_set_specific(queue2, kQueue2Key, (void *)kQueue2Key, NULL); dispatch_sync

问题 I'm having a hard time finding good examples on how to use these functions. static void * kQueue1Key = "key1"; static void * kQueue2Key = "key2"; dispatch_queue_t queue1 = dispatch_queue_create("com.company.queue1", DISPATCH_QUEUE_SERIAL); dispatch_queue_t queue2 = dispatch_queue_create("com.company.queue2", DISPATCH_QUEUE_SERIAL); dispatch_queue_set_specific(queue1, kQueue1Key, (void *)kQueue1Key, NULL); dispatch_queue_set_specific(queue2, kQueue2Key, (void *)kQueue2Key, NULL); dispatch_sync

问题 I have this block of code: DispatchQueue.main.asyncAfter(deadline: .now() + (delay * Double(isDelayAccounted.hashValue)) + extraDelay) { self.isShootingOnHold = false self.shoot() self.shootingEngine = Timer.scheduledTimer(timeInterval: (Double(60)/Double(self.ratePerMinute)), target: self, selector: #selector(ShootingEnemy.shoot), userInfo: nil, repeats: true) } Now, I want to be able to stop this thread from executing. How can I stop it from being executed? For instance, after 3 seconds, I

问题 I have the following code in viewDidLoad , which works properly on iOS 4.3, but it hangs on iOS 5/5.1. On iOS 5/5.1, the alert dialog is shown but can not be dismissed, the UI thread freezes, the OK button just can not be clicked. dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ dispatch_sync(dispatch_get_main_queue(), ^{ [self.webview stringByEvaluatingJavaScriptFromString:@"alert('HELLO WORLD!')"]; }); }); Is this a bug? 回答1: After test, I consider it as a

问题 I have the following code in viewDidLoad , which works properly on iOS 4.3, but it hangs on iOS 5/5.1. On iOS 5/5.1, the alert dialog is shown but can not be dismissed, the UI thread freezes, the OK button just can not be clicked. dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ dispatch_sync(dispatch_get_main_queue(), ^{ [self.webview stringByEvaluatingJavaScriptFromString:@"alert('HELLO WORLD!')"]; }); }); Is this a bug? 回答1: After test, I consider it as a