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    <p><strong>This solution works</strong></p> <p>Note that this solution only works if myController is accessed on a background thread the first time. It will deadlock if called on the main thread.</p> <p>You want to use gcd. The key is serialize the creation of the object, so that regardless of the threads starting the block, it will always only be created exactly once.</p> <pre><code>- (UIViewController *)myController if (_myController == nil) { dispatch_sync(dispatch_get_main_queue(), ^ { if (_myController == nil) _myController = [[MyViewController alloc] init]; }); } return _myController; } </code></pre> <p>Here, even if multiple threads execute the block, the execution of the block is serialized onto the main thread and only one MyViewController can ever be created.</p> <p>You won't see a performance hit here unless the object is nil. </p> <p>Since the property is implicitly atomic, that means that in the setter the value will be autoreleased. This should make it suitable for mingling with your custom getting, since it will autorelease any value changes to _myController.</p> <p><a href="http://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ObjectiveC/Chapters/ocProperties.html#//apple_ref/doc/uid/TP30001163-CH17-SW2" rel="nofollow noreferrer">http://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ObjectiveC/Chapters/ocProperties.html#//apple_ref/doc/uid/TP30001163-CH17-SW2</a></p> <p>However, you still may get into a race condition where you are setting the value on one thread but accessing it on another. Any time you set the value, you probably want to make sure and do something like this:</p> <p>dispatch_sync(dispatch_get_main_queue(), ^ { self.myController = {newValueOrNil} });</p> <p>This will make sure to serialize your setter methods calls without having to reinvent the wheel for atomic setters, which is very hard to get right.</p> <p><strong>This solution does not work</strong></p> <p>You want to use gcd. </p> <p><a href="http://developer.apple.com/library/ios/documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html#//apple_ref/c/func/dispatch_once" rel="nofollow noreferrer">http://developer.apple.com/library/ios/documentation/Performance/Reference/GCD_libdispatch_Ref/Reference/reference.html#//apple_ref/c/func/dispatch_once</a></p> <p>See this post about singletons. I know you don't want a singleton, but this demonstrates how to use the method. You can easily adapt it. </p> <p><a href="https://stackoverflow.com/questions/5720029/create-singleton-using-gcds-dispatch-once-in-objective-c">Create singleton using GCD&#39;s dispatch_once in Objective C</a></p>
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    1. COI'm having troubles adapting it. I can make it work like a singleton, but then I have problems when I use `[_myController release]; _myController = nil;` and then I try to create it again, since I can't reset the `static dispatch_once_t once` variable.
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    2. COHmm let me update my question with a suggestion that should work.
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    3. COThank you very much, the updated solution works perfectly.
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