ios singleton class crashes my app

Question

I have a problem with an singleton pattern.

I have read the following tutorials about singleton classes and have created my own. http://www.galloway.me.uk/utorials/sing

Answer 1

The solution of Jano must work well. I use this way too to create singleton object. And I don't have any problem.

For your code, I think that if you use @synchronized (it's not necessary cause your have dispatch_once_t as Jano said), you should not call return in @synchronized.

+ (BPManager *) bpManager {
    @synchronized(self) {
        if(sharedMyManager == nil) {
            static dispatch_once_t pred;        // Lock
            dispatch_once(&pred, ^{             // This code is called at most once per app
                sharedMyManager = [[BPManager alloc] init];
            });
        } 
    }

    return sharedMyManager;
}