nsthread

I am trying to implement an operation queue and I have the following scenario: NSOperation A NSOperation B NSOperation C NSOperation D NSOperationQueue queue I start adding A to queue . During the execution of A I need to get some data from B and I can't continue with A until B returns what I need. The same situation will occur for B depending on C and for C depending on D . To manage this, at each NSOperation I have this code: NSOperation *operation; //This can be A, B, C, D or any other NSOperation [self setQueuePriority:NSOperationQueuePriorityVeryLow]; //Set the current NSOperation with

I have test code like this - (void)viewDidLoad { [super viewDidLoad]; NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(test) object:nil]; [thread start]; } -(void)test { MyClass *my = [[[MyClass alloc] init] autorelease]; NSLog(@"%@",[my description]); } I did not create any autoreleasepool for my own thread, but when the thread exit, object "my" just dealloc.why? even though I change my test code as below - (void)viewDidLoad { [super viewDidLoad]; NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(test) object:nil]; [thread start]; } -(void

Possible Duplicate: Grand Central Dispatch (GCD) vs. performSelector - need a better explanation To execute "stuff" on the main thread, should I use dispatch_async or performSelectorOnMainThread ? Is there a preferred way, right/or wrong, and/or best practice? Example: I'm performing some logic within the block of an NSURLConnection sendAsynchronousRequest:urlRequest method. Because I'm doing stuff to the main view such as presenting a UIAlertView I need to show the UIAlertView on the main thread. To do this I'm using the following code. [NSURLConnection sendAsynchronousRequest:urlRequest

I am new in ios development. I have following questions: When we use GCD(dispatch_group_async, dispatch_async(dispatch_get_main_queue()...) and when we use performSelectorInBackground/performSelectorOnMainThread? What's the differences between those two. I know when we use performSelectorInBackground, we create a new NSThread. But isn't the same when we use dispatch_group_async? Because if we create more than one dispatch_group_async, it means we need to submit more than one blocks in queue. And those blocks might run on different queues. Therefore, when we create more than one dispatch_group

I've a big headache with the topic. I'm working on an application that needs to poll a webserver regularly, in order to check for new data. Based on the returned information, I wish to push a local notification to the user. I know that this approach is slightly different from the one depicted by Apple, in which a remote server makes the work, pushing a remote notification, based on APNS. However, there are many reasons for which i cannot take this approach in consideration. One for all, is the user authentication mechanism. The remote server, for security reasons, cannot take into account the

I know UIView are not thread safe so i cant add a view on a background thread, to work around this is it ok to create a UIView on a background thread then add it on the main thread? Note: the reason im not doing this on the main thread is because my actual code is a lot more complex and therefor takes a while to create all the views and fill the values. I dont want the UI to become un-responsive when I do this so im trying to work around this. for example.. -(void)addLabel//called on background thread { UILabel * label = [[UILabel alloc]initWithFrame:CGRectMake(0,0,40,100)]; [label setText:@