Question

I’m guessing this must be new functionality as this code fail on my iOS4 device, works fine on iOS5. I need this to work on both. I haven’t moved to iOS5 yet as I still need to support iOS4, so I’m at a loss as how to workaround this ?

static dispatch_once_t oncePredicate;
dispatch_once(&oncePredicate, ^{ //EXC_BAD_ACCESS
   _sharedStoreManager = [[super allocWithZone:nil] init];            
});

It’s from https://github.com/MugunthKumar/MKStoreKit/blob/master/MKStoreManager.m

Answer 1

dispatch_once() is not new with iOS 5.0, it’s been around since 4.0. I use it all the time in applications that target 4.0, such as in this singleton from one of my frameworks:

+ (GPUImageOpenGLESContext *)sharedImageProcessingOpenGLESContext;
{
    static dispatch_once_t pred;
    static GPUImageOpenGLESContext *sharedImageProcessingOpenGLESContext = nil;

    dispatch_once(&pred, ^{
        sharedImageProcessingOpenGLESContext = [[GPUImageOpenGLESContext alloc] init];
    });
    return sharedImageProcessingOpenGLESContext;
}

From Apple’s documentation:

Availability

Available in iOS 4.0 and later.

I’m guessing your problem exists within the -init of your _sharedStoreManager. For example, is there a reason why you are using -allocWithZone: there?