SKNode上的runAction无法完成

Question

我使用子类NSOperation来获取SKAction的序列执行，如本问题所述：How to subclass NSOperation in Swift to queue SKAction objects for serial execution?

然后，我修改了上一个子类，以便为多个节点分组动画：https://stackoverflow.com/a/30600718/540780

最后，因为我需要在SKAction完成后运行完成块，所以我使用struct数组而不是元组数组稍微修改了代码。

struct ActionData {
    let node:SKNode
    let action:SKAction
    let completion: () -> ()

    init (node:SKNode, action:SKAction, completion:() -> () = {}) {
        self.node = node
        self.action = action
        self.completion = completion
    }
}

class ActionOperation : NSOperation
{

    let _theActions:[ActionData]

    var _finished = false // Our read-write mirror of the super's read-only finished property
    var _executing = false // Our read-write mirror of the super's read-only executing property

    var _numberOfOperationsFinished = 0 // The number of finished operations


    /// Override read-only superclass property as read-write.
    override var executing:Bool {
        get { return _executing }
        set {
            willChangeValueForKey("isExecuting")
            _executing = newValue
            didChangeValueForKey("isExecuting")
        }
    }

    /// Override read-only superclass property as read-write.
    override var finished:Bool {
        get { return _finished }
        set {
            willChangeValueForKey("isFinished")
            _finished = newValue
            didChangeValueForKey("isFinished")
        }
    }


    // Initialisation with one action for one node
    //
    // For backwards compatibility
    //
    init(node:SKNode, action:SKAction) {
        let donnees = ActionData(node: node, action: action, completion: {})
        _theActions = [donnees]

        super.init()
    }

    init (lesActions:[ActionData]) {
        _theActions = lesActions

        super.init()
    }

    func checkCompletion() {
        _numberOfOperationsFinished++

        logGeneral.debug(">> Block completed: \(self._numberOfOperationsFinished)/\(self._theActions.count) " + self.name!)

        if _numberOfOperationsFinished ==  _theActions.count {
            self.executing = false
            self.finished = true
            logGeneral.debug("Operation Completed: " + self.name!)
        }

    }

    override func start()
    {
        if cancelled {
            finished = true
            return
        }

        executing = true

        if name == nil {
            name = "unknown"
        }


        _numberOfOperationsFinished = 0
        var operation = NSBlockOperation()

        var compteur = 0
        for actionData in _theActions {
            compteur++

            var actionName = "???"
            if let name = actionData.node.name {
                actionName = name
            }

            logGeneral.debug("operation : \(compteur)/\(self._theActions.count) " + self.name! + " " + actionName)
            operation.addExecutionBlock({
                actionData.node.runAction(actionData.action,completion:{
                    actionData.completion()
                    self.checkCompletion() })
            })
        }

        logGeneral.debug("Execute: " + self.name!)
        NSOperationQueue.mainQueue().addOperation(operation)

    }
}

主要思想是通过添加ActionData类型的数据来详细说明动画，将它们附加到数组并将此数组传输到ActionAnimation对象。

在一些随机的情况下，有些runAction没有完成：它们会启动，但其中一些随机无法完成。这是一个典型的日志，其中6个块开始但只完成了5个：

start(): operation : 1/6 ???
start(): operation : 2/6 suppressionPion1
start(): operation : 3/6 suppressionPion2
start(): operation : 4/6 suppressionPion3
start(): operation : 5/6 suppressionPion4
start(): operation : 6/6 suppressionGroupe1
start(): Execute: animerSupprimer
checkCompletion(): >> Block completed: 1/6
checkCompletion(): >> Block completed: 2/6
checkCompletion(): >> Block completed: 3/6
checkCompletion(): >> Block completed: 4/6
checkCompletion(): >> Block completed: 5/6

在这种情况下，只有一个runAction未能完成，在其他情况下只有2,3，或者没有。

我真的不明白问题的来源。

更新

在某些情况下，应用程序在主线程上与EXC_BAD_ACCESS崩溃。这似乎与SKCSprite::update(double)有关：