Singleton in iOS Objective C doesn't prevent more than one instance

Question

I know there are several threads on this, but none answer my questions.

I\'ve implemented my singleton class like this (being aware of the controversy about singleto

Answer 1

This works for me:

static AudioRecordingGraph * __strong sharedInstance;

+(instancetype)sharedInstance {

    @synchronized(self) {

        if(!sharedInstance) {

            sharedInstance = [AudioRecordingGraph new];
        }
        return sharedInstance;
    }
}