There is no downside. Use it. Do it today. It is faster than your old code. It is safer than your old code. It is easier than your old code. It is not garbage collection. It has no GC runtime overhead. The compiler inserts retains and releases in all the places you should have anyway. … Read more
In exactly the same way that you (should) have been doing it already: + (instancetype)sharedInstance { static MyClass *sharedInstance = nil; static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ sharedInstance = [[MyClass alloc] init]; // Do any other initialisation stuff here }); return sharedInstance; }
Short answer Instead of accessing self directly, you should access it indirectly, from a reference that will not be retained. If you’re not using Automatic Reference Counting (ARC), you can do this: __block MyDataProcessor *dp = self; self.progressBlock = ^(CGFloat percentComplete) { [dp.delegate myAPI:dp isProcessingWithProgress:percentComplete]; } The __block keyword marks variables that can be modified … Read more
ARC doesn’t get rid of retains, releases and autoreleases, it just adds in the required ones for you. So there are still calls to retain, there are still calls to release, there are still calls to autorelease and there are still auto release pools. One of the other changes they made with the new Clang … Read more
After reading so many articles Stackoverflow posts and demo applications to check variable property attributes, I decided to put all the attributes information together: atomic //default nonatomic strong=retain //default weak retain assign //default unsafe_unretained copy readonly readwrite //default Below is the detailed article link where you can find above mentioned all attributes, that will definitely … Read more
The following code describes a simple example using POST method.(How one can pass data by POST method) Here, I describe how one can use of POST method. 1. Set post string with actual username and password. NSString *post = [NSString stringWithFormat:@”Username=%@&Password=%@”,@”username”,@”password”]; 2. Encode the post string using NSASCIIStringEncoding and also the post string you need … Read more
Every new developer who comes to Objective-C has to learn the rigid rules of when to retain, release, and autorelease objects. These rules even specify naming conventions that imply the retain count of objects returned from methods. Memory management in Objective-C becomes second nature once you take these rules to heart and apply them consistently, … Read more
Nonatomic Nonatomic will not generate threadsafe routines thru @synthesize accessors. atomic will generate threadsafe accessors so atomic variables are threadsafe (can be accessed from multiple threads without botching of data) Copy copy is required when the object is mutable. Use this if you need the value of the object as it is at this moment, … Read more
In Xcode 8, you can click on the “Debug Memory Graph” button, in the debug toolbar (shown at the bottom of the screen): Just identify the object in the left panel that you think should have been deallocated, and it will show you the object graph (shown in the main canvas, above). This is very … Read more
No, there are definitely times where you would not want to use [unowned self]. Sometimes you want the closure to capture self in order to make sure that it is still around by the time the closure is called. Example: Making an asynchronous network request If you are making an asynchronous network request you do … Read more