nsoperation

How to use NSOperation and dispatch queue

由 半腔热情 提交于 2019-12-08 14:00:00
问题 I am using NSoperation in Initiating request to server.Pullparser will be called and it will initiate a o/p & i/p stream.In connecitonDidRecievedata I am writing data coming from server to oStream.Imeediately I have to call custom method instead of letting the parser start parsing.How to handle this case.How to handle the ostream call to parser and handle my custom method first then in my custom method I have to call the parser. - (void)run { [gObjAppDelegatePtr displayActivityIndicator];

What's the best way to set up concurrent execution of for loops in Objective C?

由 ☆樱花仙子☆ 提交于 2019-12-08 12:10:23
问题 I have a situation with a time-intensive for loop like this: int sum = 0; for (int i = 0; i < max; ++i) sum += dosomething(i); The do something(i) calls are independent. This cries out for multithreading. Using NSOperationQueue on a two-core machine, I can do this: int __block midpoint; int __block sum1; int __block sum2; midpoint = max/2; sum1 = 0; sum2 = 0; NSOperationQueue *queue = [[NSOperationQueue alloc] init]; NSOperation *operation = [NSBlockOperation blockOperationWithBlock: ^{ for

NSOperationQueue and UITableView release is crashing my app

由 淺唱寂寞╮ 提交于 2019-12-08 12:02:54
问题 This is by far the weirdest problem I've been stuck with. I have a UIViewController on a UINavigationController and I want to call a method at viewDidAppear using NSInvocationOperation so it can run on a back thread when the view becomes visible. The problem is that if I pop the view controller BEFORE the operation (in this case the testMethod method) completes running, the app crashes. Everything works fine if I pop the view controller AFTER the operation runs it's course. When the app

Cancelling NSOperation from NSOperationQueue cause crash

由 倖福魔咒の 提交于 2019-12-07 22:55:22
问题 I'm trying to build a download manager class that packets all the async download (every op has its own thread) operation in an NSOperation subclass to add them later in an NSOperationQueue. The download manager class (a singleton) also exposes few methods to work on the queue and cancel operations that matches some requirements. Those are steps to start creating kind of a Class Cluster(Abstract Factory) that returns different kinds of NSOperation for different types of common operation

[NSBlockOperation addExecutionBlock:]: blocks cannot be added after the operation has started executing or finished

由 邮差的信 提交于 2019-12-07 18:14:33
问题 I am trying to start again NSBlockOperation after completing or canceling it, but getting an error? Any one have any idea where is mistake? Thanks let imageURLs = ["http://www.planetware.com/photos-large/F/france-paris-eiffel-tower.jpg", "http://adriatic-lines.com/wp-content/uploads/2015/04/canal-of-Venice.jpg", "http://algoos.com/wp-content/uploads/2015/08/ireland-02.jpg", "http://bdo.se/wp-content/uploads/2014/01/Stockholm1.jpg"] class Downloader { class func downloadImageWithURL(url:String

文檔翻譯：NSOperation Class Reference

由 Deadly 提交于 2019-12-07 14:19:33
NSOperation Class Reference NSOperation 類參考 本文PDF版本： http://db.tt/A1xLPVXq 。（排版較佳） 轉載請註明出處，謝謝。 原文網址：http://developer.apple.com/documentation/Cocoa/Reference/NSOperation_class/Reference/Reference.html。(Last updated: 2012-01-09) 本文網址：http://my.oschina.net/KSHime37。(2012-09-18) Overview 概論 The NSOperation class is an abstract class you use to encapsulate the code and data associated with a single task. Because it is abstract, you do not use this class directly but instead subclass or use one of the system-defined subclasses (NSInvocationOperation or NSBlockOperation) to perform the actual task.

Why is my NSOperation subclass never finishing?

由 瘦欲@ 提交于 2019-12-07 10:31:09
问题 I have an NSOperation subclass that I want to run concurrently. My understanding is that for concurrent operations to work: I need to define isConcurrent to return YES . I need to define the start method I need to send KVOs notification for isExecuting and isFinished when it's done. Using @synthesize will automatically send the appropriate KVO notifications when the values for isExecuting and isFinished are changed. Despite this, I have verified that my queue never moves on to the next item.

iOS multiple threads(2)------NSOperation NSOper...

由 荒凉一梦 提交于 2019-12-06 23:47:13
首先，简单区分这几个类关键词： NSOperation ：可以理解程一个“操作”，一个要做的事件，感觉类似如java中的runnable，NSOperation只有添加到线程队列中才能被执行。 NSOperationQueue ：可以勉强的叫做线程队列吧，他是专门管理添加到他里面NSOperation，然后根据情况，开启线程执行对应的“操作”，java作用，也有对应的类，或者我们自己写一个队列。 NSOperationQueue的目的就是多线程管理，一个NSOperationQueue 操作队列，就相当于一个线程管理器，而非一个线程。因为你可以设置这个线程管理器内可以并行运行的的线程数量等等。 下面是建立并初始化一个操作队列,而且我们可以设置这个队列每次被处理的“操作（NSOperation）”数量: NSOperationQueue *aQ = [[NSOperationQueue alloc] init]; [aQ setMaxConcurrentOperationCount:10]; 然后，我们后面就可以建立需要操作的任务啦，然后加到操作队列中，就可以实现队多线程啦，ios中，使用NSInvocationOperation（NSOperation的子类）是最简单的多线程编程方式，在iPhone编程中是经常被用到的 /创建一个NSInvocationOperation对象

ios NSOperationQueue, operations all run when added and don't queue

由 守給你的承諾、 提交于 2019-12-06 15:13:31
问题 So, I have a group of ASINetworkQueues that currently run together resulting in a race condition when it comes to DB saves. I am trying to create an NSOperationQueue that will will queue each of these "sub queues". I currently have created an NSOperation with a main method that kicks off the "sub queue" to start it's download. My problem is that each time I add a sub queue to the main queue using "addOperation" it fires that "main" method straight away so my sub queues run concurrently. I was

Cancelling NSOperation from NSOperationQueue cause crash

由 試著忘記壹切 提交于 2019-12-06 09:35:30
I'm trying to build a download manager class that packets all the async download (every op has its own thread) operation in an NSOperation subclass to add them later in an NSOperationQueue. The download manager class (a singleton) also exposes few methods to work on the queue and cancel operations that matches some requirements. Those are steps to start creating kind of a Class Cluster(Abstract Factory) that returns different kinds of NSOperation for different types of common operation (upload, download,parse, etc). The class seems to work pretty well with download operations, but if in the
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