ADInterstitialAd causing memory issues

Question

I've been developing an iPhone / iPad game using Sprite Kit and in between each round I load an interstitial advert.

The interstitial is loaded on the main GameViewController and sits on top of the skview. I use a series of observers to trigger and cancel adverts and this all seems to work fine.

However, I've noticed some serious memory issues and after 4 or 5 rounds the app will crash. It appears to be directly related to the iAd interstitial. I've attached my code and you can see that I'm deallocating the objects, but the memory foot print does not seem to drop. I am using ARC too.

Does anyone know what could be causing this issue? I did read here: iAd & AdMob Heavy on Memory that the webkit view seems to hold on to its contents. I need to find a way to fix this, my code for my GameViewController is as follows:

#pragma mark - GAME LOAD
-(void)loadStartScreen{
    _theView = (SKView *) self.view;
    _theView.showsFPS = YES;
    _theView.showsNodeCount = YES;
    //Sprite Kit applies additional optimizations to improve rendering performance
    _theView.ignoresSiblingOrder = YES;

    // Create and configure the scene.
    _theScene = [MainMenuScene sceneWithSize:_theView.bounds.size];
    _theScene.scaleMode = SKSceneScaleModeAspectFill;
    _theScene.backgroundColor = [UIColor grayColor];

    // Present the scene
    [_theView presentScene:_theScene];

    // setup observer
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(requestFullScreenAd) name:@"requestAdvert" object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(showFullScreenAd) name:@"showAdvert" object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(cancelAdverts) name:@"cancelAdvert" object:nil];
}

#pragma mark - ADVERT CREATION AND SUPPORT
-(void)requestFullScreenAd {
    // run the process on the main thread in a background queue
    dispatch_async(bGQueue, ^{
        if (_requestingAd == NO) {
            _interstitial = [[ADInterstitialAd alloc]init];
            _interstitial.delegate = self;
            self.interstitialPresentationPolicy = ADInterstitialPresentationPolicyManual;
            NSLog(@"Ad Request");
            _requestingAd = YES;
        }
    });
}

-(void)showFullScreenAd{
    if (_adLoaded) {
        CGRect interstitialFrame = self.view.bounds;
        interstitialFrame.origin = CGPointMake(0, 0);
        _adView = [[UIView alloc] initWithFrame:interstitialFrame];
        [self.view addSubview:_adView];

        [_interstitial presentInView:_adView];

        _button = [UIButton buttonWithType:UIButtonTypeCustom];
        [_button addTarget:self action:@selector(closeAd:) forControlEvents:UIControlEventTouchDown];
        _button.backgroundColor = [UIColor clearColor];
        [_button setBackgroundImage:[UIImage imageNamed:kCloseAd] forState:UIControlStateNormal];
        _button.frame = CGRectMake(10, 10, 40, 40);
        _button.alpha = 0.75;
        [_adView insertSubview:_button aboveSubview:_adView];

        [UIView beginAnimations:@"animateAdBannerOn" context:nil];
        [UIView setAnimationDuration:1];
        [_adView setAlpha:1];
        [UIView commitAnimations];
    }
}

-(void)closeAd:(id)sender {
    [UIView beginAnimations:@"animateAdBannerOff" context:nil];
    [UIView setAnimationDuration:1];
    [_adView setAlpha:0];
    [UIView commitAnimations];

    _adView=nil;
    _requestingAd = NO;
    _button = nil;
    _interstitial.delegate = nil;
    _interstitial = nil;

    // notification for ad complete
    [[NSNotificationCenter defaultCenter] postNotificationName:@"adClosed" object:nil]; 
}

-(void)cancelAdverts{
    [_interstitial cancelAction];
    _adView=nil;
    _requestingAd = NO;
    _button = nil;
    _interstitial.delegate = nil;
    _interstitial = nil;
}

#pragma mark - IAD DELEGATE
-(void)interstitialAd:(ADInterstitialAd *)interstitialAd didFailWithError:(NSError *)error {
    [_interstitial cancelAction];
    _adView=nil;
    _requestingAd = NO;
    _button = nil;
    _interstitial.delegate = nil;
    _interstitial = nil;
    NSLog(@"Ad didFailWithERROR");
    NSLog(@"%@", error);

    // request another advert if it failed
    //[self requestFullScreenAd];
}

-(void)interstitialAdDidLoad:(ADInterstitialAd *)interstitialAd {
    if (interstitialAd.loaded) {
        _adLoaded = YES;
        [[NSNotificationCenter defaultCenter]postNotificationName:@"adLoaded" object:nil];
    }
    NSLog(@"Ad DidLOAD");
}

-(void)interstitialAdDidUnload:(ADInterstitialAd *)interstitialAd {
    [self closeAd:nil];
    NSLog(@"Ad DidUNLOAD");
}

-(void)interstitialAdActionDidFinish:(ADInterstitialAd *)interstitialAd {
    [self closeAd:nil];
    NSLog(@"Ad DidFINISH");
}

Then in my level complete SKScene:

#pragma mark - SCENE APPEARS
-(void)didMoveToView:(SKView *)view {
    // request an advert if advert removal is not purchased
    if (![[[UserDetails sharedManager]iapAdsRemoved]boolValue]) {
        // send request ad notification
        [[NSNotificationCenter defaultCenter]postNotificationName:@"requestAdvert" object:nil];
        // look for add loaded notification
        [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(adLoaded) name:@"adLoaded" object:nil];
        // look for add completed
        [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(adShowCompleted) name:@"adClosed" object:nil];
    }

    // setup UI
    [self createUI];

    if (![[UnlockController sharedManager]allunlocksOpen]) {
        // check all unlocks
        [[UnlockController sharedManager]checkUnlocks:[[UserDetails sharedManager]userTotalScore]+[[UserDetails sharedManager]userLevelScore]];

        // get the next unlock
        [self getNextUnlockScore];

        // set bar with correct increment
        [unlockBar setBarValues:[[UserDetails sharedManager]userTotalScore]+[[UserDetails sharedManager]userLevelScore] increment:[[UserDetails sharedManager]userTotalScore] nextObject:nextScore];
    }
    else{
        [self allUnlocksOpen];
    }

    // pre add button
    preAdButtonPress = 3;

    // variables
    startCount = 0;
    unlockItemsCount = 0;
    allUnlocks = [[UnlockController sharedManager]finalUnlockOpen];

    // start unlocks sequence
    [self performSelector:@selector(runRewards) withObject:nil afterDelay:1.0];
}

-(void)willMoveFromView:(SKView *)view{
    // cancel any adverts
    [[NSNotificationCenter defaultCenter]postNotificationName:@"cancelAdvert" object:nil];
    // remove observers
    [[NSNotificationCenter defaultCenter]removeObserver:@"adClosed"];
    [[NSNotificationCenter defaultCenter]removeObserver:@"adLoaded"];
}

Answer 1

Was a memory issue with some core code rather than the iad causing memory leaks.