Reloading all view controllers in a tab bar controller - ios

Question

I have an iPad app with a UITabBarController with 7 view controllers.
This is in my applicationDidFinishLaunching:
// Override point for customization after application launch.
self.tabBarController = [[UITabBarController alloc] init];
self.tabBarController.delegate = self;
self.tabBarController.viewControllers = [self createViewControllers];
self.window.rootViewController = self.tabBarController;
And this also in my appDelegate:
- (NSArray *)createViewControllers
{
MyView1 *viewController1 = [[MyView1 alloc] initWithNibName:#"MyView1" bundle:nil];
MyView2 *viewController2 = [[MyView2 alloc] initWithNibName:#"MyView2" bundle:nil];
MyView3 *viewController3 = [[MyView3 alloc] initWithNibName:#"MyView3" bundle:nil];
MyView4 *viewController4 = [[MyView4 alloc] initWithNibName:#"MyView4" bundle:nil];
MyView5 *viewController5 = [[MyView5 alloc] initWithNibName:#"MyView5" bundle:nil];
MyView6 *viewController6 = [[MyView6 alloc] initWithNibName:#"MyView6" bundle:nil];
MyView7 *viewController7 = [[MyView7 alloc] initWithNibName:#"MyView7" bundle:nil];
NSArray *views = [NSArray arrayWithObjects:viewController1, viewController2, viewController3, viewController4, viewController5, viewController6, viewController7, nil];
return views;
}
At any time, I want the user to be able to completely reload those view controllers, so any changes made, any animations in progress, any subviews etc, are flushed from memory and the view controllers are all loaded afresh.
I found the simplest way to do this is to add a shake gesture in the appDelegate. The shake gesture pops up a UIAlertView which asks "Do you want to reset everything?" If yes, this happens:
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if (buttonIndex == 1) {
self.tabBarController.viewControllers = [self createViewControllers]; // <-- this happens
// some of the other things I've tried
// [self.tabBarController setViewControllers:[self createViewControllers] animated:YES]; // same as above but with animation
// self.tabBarController = [[UITabBarController alloc] init]; // allocations go crazy!
// self.tabBarController.delegate = self;
// self.tabBarController.viewControllers = [self createViewControllers];
// self.window.rootViewController = self.tabBarController;
}
}
I replace the array of view controllers with a freshly created set. You can see a couple of the other things I've tried as well.
What I don't understand is why every time the reset is performed, the allocations in Instruments go up (and stay up) and the app starts to slow down. The more I reset, the more it slows down until it becomes unusable.
I'm using ARC and I would expect it to take care of the memory management each time I refresh the view controllers in the tab bar controller. Yet each refresh eats up more memory, no matter how I do it.
What could it be that is slowing everything down?