automatic-ref-counting

Say, I want to create a singleton which has some data inside. The data is dynamically allocated only once, as it expected on singleton. But I would like to now under when and how this data can be is released. Should I establish special method which will destroy the singleton? To be more specific - when the method 'dealloc' for this singleton will be executed? who is responsible for that? You can declare a method/function you call explicitly. The simplest way is to have a static C++ class hold it, then release it in its destructor. If you have multiple singletons, then this approach does not

I have an object that holds a strong reference to a object: @property (nonatomic, strong) NSObject *thing; Elsewhere, I have a method that passes the object reference: [thirdObject doSomething:secondObject.thing]; In one case (out of a million or billion), thirdObject ended up working with a dangling pointer, because the object got swapped and had no owner. Can I avoid this by doing this? Is this different for ARC? NSObject *thing = secondObject.thing [thirdObject doSomething:secondObject.thing]; If not, how can I avoid this? Edit: Message is "message sent to deallocated instance 0xwhatever"

i'm cracking my head on memory issues with my app, the app are working fine except that it will crash once it hit low memory warning and are very very very laggy when using it for 10 to 20 minutes. EDIT: how to poptoviewcontroller? introvideo-> welcomeview & tutorialview-> mainviewcontroller-> scannerviewcontoller-> questionview ->(if answer correct -> correctView) else ->wrongView how do i pop back to mainView controller ? the below code are to solve adding view controller to the navigationcontroller.viewcontroller stack. As i'm using storyboard pushing from viewcontroller to another view

For some reason I want a block to execute during the next iteration of the run loop, so I came up with: typedef void (^resizer_t)() ; - (void) applyResizer: (resizer_t) resizer { resizer() ; Block_release(resizer) ; } - (void) usage { ... resizer_t resizer = ^() { // stuff } ; [self performSelectorOnMainThread:@selector(applyResizer:) withObject:(__bridge id) Block_copy((__bridge void *) resizer) waitUntilDone:NO] ; } Isn't it ironic that I have to cast to void * the argument to Block _copy ? Why is the compiler happy with my Block_release when it chokes on Block_copy without the bridge void *

Here is my code: extern void _objc_autoreleasePoolPrint(); int main(int argc, const char * argv[]) { NSArray __weak *tmp = nil; @autoreleasepool { NSArray __strong *obj = [[NSArray alloc] init]; NSLog(@"obj &: %p", obj); tmp = obj; NSLog(@"tmp &: %p", tmp); _objc_autoreleasePoolPrint(); } NSLog(@"tmp: %@", tmp); // why not (null) ? return 0; } And console output: 2013-05-01 22:14:32.966 SimpleConsoleObjectiveCApplicationWithARC[40660:f07] obj &: 0x7fedf9403110 2013-05-01 22:14:32.969 SimpleConsoleObjectiveCApplicationWithARC[40660:f07] tmp &: 0x7fedf9403110 objc[40660]: ############## objc

When using manual memory management we can write a call to a method which is not declared in the class. What we get during compilation in this case is warning only. This is what Wikipedia states on one of the most distinctive Objective-C features: The Objective-C model of object-oriented programming is based on message passing to object instances. In Objective-C one does not simply call a method; one sends a message. This is unlike the Simula-style programming model used by C++. The difference between these two concepts is in how the code referenced by the method or message name is executed.

I opened up an older project of mine and chose Convert to Objective-C ARC from the Edit/Refactor menu. I am getting the following error: Apple LLVM compiler 3.0 Error Error in format of file: /Users/myUserName/Library/Developer/Xcode/DerivedData/ProjectName-fkjvtdsoypoyrdcedtarbtypupor/Build/Intermediates/ProjectName.build/Debug-iphoneos/ProjectName.build/ProjectName-arc.migrate/remap Is this one of those situations where I need to manually delete some files/folders in Finder and then try it again? I just deleted everything in the "Build" folder of the project, then did Product/Clean and tried