removeFromSuperview() Not Removing Reference To View, CPU Load Remains High - ios

Question

I have an activity indicator that I created. It's a series of five UIViews that animate their alphas from 0.0 -> 1.0 for about 3 seconds a piece. In the device profile the CPU is over 100% and energy usage is "Very High". The profile levels remain at that height even after running .removeFromSuperview() on the container view of the activityIndicator, also the same if I remove each subview from the container view and then the container itself.
My question is what is the proper way to remove a series of views from a parent view so they no longer are referenced? Or I suppose that I could be asking the wrong question, maybe it's not in the removal but in the implementation of the activity view. Why would that type of simple animation create such a high CPU load?
The high load happens most specifically when the activityIndicator is placed in a viewController over a nested tableView while the tableView loads.
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(true)
if currentMatchObject == nil {
let indicator = SquaresActivityIndicator()
checkForUser(self) { () -> () in
delay(2.0, closure: { () -> () in
indicator.stopIndicator(self.view)
dispatch_async(dispatch_get_main_queue(), { () -> Void in
self.matchTableView.frame.size.width = self.view.frame.width
self.matchTableView.frame.size.height = self.view.frame.height * 0.75
self.matchTableView.frame.origin.y = self.view.frame.height * 0.10
self.matchTableView.frame.origin.x = centerXAlignment(self.matchTableView, masterView: self.view)
self.matchTableView.backgroundColor = bgColor
})
})
self.reloadMatchView()
}
indicator.runIndicator(self.view, percentageSize: 15.0, activityBorderWidth: 6.0)
} else {
self.reloadMatchView()
}
}
ActivityIndicator stop function:
func stopIndicator(masterView: UIView) {
let viewToRemove = masterView.viewWithTag(123)
for v in (viewToRemove?.subviews)! {
v.removeFromSuperview()
}
viewToRemove?.removeFromSuperview()
}

Answer 1

In most cases this problem with animations or iterations in another threads.
How detect code?
Attention: as example i use my application.
Run instruments and choose Time
Start application and "go to" high load processor. Wait few seconds for aggregate information. The next, find own method ;)
And, code in this method:
- (void)animateKeep
{
CGFloat angle = self.activeAngle;
if (self.turnToLeft) {
angle += 90;
} else {
angle -= 90;
}
self.activeAngle = angle;
[UIView animateWithDuration:self.angleSpeed * 3 delay:.0f options:UIViewAnimationOptionCurveLinear animations:^{
self.transform = CGAffineTransformMakeRotation(DegreesToRadians(angle));
} completion:^(BOOL finished) {
[self animateKeep];
}];
}
And we see loop animation in completion code [self animateKeep]. And we should control all animation and stop animation before remove from superview.
Solution in this example - add custom flag (bool) and in start method control this flag.
Solution:
You should stop all animations and iterations (if exist in another thread) for this view before remove from superview.