使用UICollectionView在iOS 9中奇怪的100％CPU使用率

Question

I have a tableView, in each cell there is a collectionView. Sometimes when I know there is new data in collectionViews, I call reloadData() on collectionView. Most of the time this routine works, but but sometimes is starts to use 100% of CPU, memory usage increasing, GUI is blocked, and at a point app will crash. If I do not let reload collectionView, then all works well, only the content invalid in the collectionView. What is going on, in iOS 8 it was not a problem to call reloadData() from cellForRowAtIndexPath .

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCellWithIdentifier("movie") as! MovieTableViewCell

    //..

    if cell.rcvc == nil {

        let cvfl = UICollectionViewFlowLayout()
        cvfl.scrollDirection = .Horizontal
        cell.rcvc = RatingCollectionViewController(collectionViewLayout: cvfl)

        self.addChildViewController(cell.rcvc!)
        let v = cell.viewWithTag(5)!
        v.addSubview(cell.rcvc!.view)
        cell.rcvc!.didMoveToParentViewController(self)
        cell.rcvc!.view.frame = v.bounds
    }

    cell.rcvc!.movie = movie

    if enableReloadRatingCollectionViews {

        cell.rcvc!.collectionView!.reloadData() // <--- if I comment, not crashes
    }

    return cell
}

UPDATE

I have updated my code like @dasblinkenlight suggest, I am not calling reloadData anymore from cellforRowAtIndexPath , but now call reloadData for all collectionView s form outside when certain user interaction triggers it. But it still crashes sometimes, any idea why?

itemTableViewController!.tableView.reloadData()
for sv in collectionViews.allObjects {

    (sv as! UICollectionView).reloadData()
}

Answer 1

Instead of reloading the nested collectionView , I implemented a configureCell method, that reset cell, and for all the visible cell I call configureCell . That is my fix, and so the infinite loop can avoid.