iOS App crashed com.apple.root.background-qos

Question

アプリケーションでアプリケーションクラッシュが見つかりました。私は、これが火星観測者のコードのために起こりうると思う。ユーザーの場合、ユーザーはあるイベントから（このイベントに参加している）ユーザープロファイルに行くことができるので、ユーザープロファイルからこのイベントに戻ることができます。特定のオブザーバーを削除するための参照が必要でした。このため、私は次のコードを作った。

コード

fileprivate func firObserve(_ isObserve: Bool) { 
    guard card != nil else { return } 
    firCardObserverDBManager.observeParticipationCard(observer: self, card: card, isObserve: isObserve, success: { [weak self] (updatedCard) in 
      debugPrint("updated card") 
      self?.checkUpdatedCard(updatedCard) 
     }, removed: { [weak self] in 
      self?.isParticipationCardDateRemoved = true 
      self?.presentCardRemovedAlert() 
    }) { (error) in 
     DispatchQueue.main.async { 
      SVProgressHUD.showError(withStatus: error.localizedDescription) 
     } 
    } 
} 

のスニペットそれ

extension UIViewController { 

    private struct FirebaseQueues { 
     static var firQueues = [DatabaseQuery]() 
    } 

    var firQueues: [DatabaseQuery] { 
     get { 
      guard let firQueues = objc_getAssociatedObject(self, &FirebaseQueues.firQueues) as? [DatabaseQuery] else { return [] } 
      return firQueues 
     } 
     set { 
      objc_setAssociatedObject(self, &FirebaseQueues.firQueues, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC) 
     } 
    } 

    private struct FirebaseReferences { 
     static var firReferences = [DatabaseReference]() 
    } 

    var firReferences: [DatabaseReference] { 
     get { 
      guard let firReferenses = objc_getAssociatedObject(self, &FirebaseReferences.firReferences) as? [DatabaseReference] else { return [] } 
      return firReferenses 
     } 
     set { 
      objc_setAssociatedObject(self, &FirebaseReferences.firReferences, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC) 
     } 
    } 

    func removeFIRQueuesReferensesObservers() { 
     for firQueqry in firQueues { 
      firQueqry.removeAllObservers() 
     } 
     firQueues.removeAll() 
     for firRef in firReferences { 
      firRef.removeAllObservers() 
     } 
     firReferences.removeAll() 
    } 

} 

クラッシュのためのUIViewControllerの拡張子

fileprivate var observeParticipationCardObservers = NSMapTable<AnyObject, AnyObject>(keyOptions: .weakMemory, valueOptions: .strongMemory) 


func observeParticipationCard(observer: Any, card: CardModel, isObserve: Bool, success: ((_ updatedCard: CardModel) -> Void)?, removed: (() -> Void)?, fail: ((_ error: Error) -> Void)?) { 
    let ref = Database.database().reference().child(MainGateways.cards.rawValue).child(card.id) 

    if !isObserve { 
     guard let handle = self.observeParticipationCardObservers.object(forKey: observer as AnyObject) as? UInt else { return } 
     ref.removeObserver(withHandle: handle) 
     observeParticipationCardObservers.removeObject(forKey: observer as AnyObject) 
     return 
    } 

    if let observableVC = observer as? UIViewController { 
     observableVC.firReferences.append(ref) 
    } 

    DispatchQueue.global(qos: .background).async { 
     let handle = ref.observe(.value, with: { (snapshot) in 
      if snapshot.value is NSNull { 
       // not exist 
       removed?() 
      } 
      guard let json = snapshot.value as? [String : Any] else { return } 
      guard let updatedCard = Mapper<CardModel>().map(JSON: json) else { return } 
      success?(updatedCard) 
     }, withCancel: { (error) in 
      debugPrint(error.localizedDescription) 
      fail?(error) 
     }) 
     self.observeParticipationCardObservers.setObject(handle as AnyObject, forKey: observer as AnyObject) 
     debugPrint("observeParticipationCardObservers", self.observeParticipationCardObservers) 
    } 
} 

FIRCardObserverDBManager

から

Crashed: com.apple.root.background-qos 
    0 libswiftCore.dylib    0x1022ba574 swift_unknownRelease (__hidden#21375_:381) 
    1 myapp      0x1002e3fd0 specialized specialized _ArrayBufferProtocol._arrayOutOfPlaceUpdate<A where ...> (inout _ContiguousArrayBuffer<A.Element>, Int, Int, A1) ->() (EventsUpcomingVC.swift) 
    2 myapp      0x1002e0eb8 specialized Array._copyToNewBuffer(oldCount : Int) ->() (EventsUpcomingVC.swift) 
    3 myapp      0x100319a84 specialized ChatGeneralManager.(observeConversationModel(Bool, conversationID : String, updated :() ->()?, fail : (Error) ->()?) ->()).(closure #1).(closure #1) (ChatGeneralManager.swift) 
    4 myapp      0x100311f70 ChatGeneralManager.(observeConversationModel(Bool, conversationID : String, updated :() ->()?, fail : (Error) ->()?) ->()).(closure #1).(closure #1) (ChatGeneralManager.swift) 
    5 myapp      0x10032515c partial apply for ChatGeneralManager.(observeConversationModel(Bool, conversationID : String, updated :() ->()?, fail : (Error) ->()?) ->()).(closure #1).(closure #1) (ChatGeneralManager.swift) 
    6 libdispatch.dylib    0x185b9e9e0 _dispatch_call_block_and_release + 24 
    7 libdispatch.dylib    0x185b9e9a0 _dispatch_client_callout + 16 
    8 libdispatch.dylib    0x185baebac _dispatch_root_queue_drain + 888 
    9 libdispatch.dylib    0x185bae7d0 _dispatch_worker_thread3 + 124 
    10 libsystem_pthread.dylib  0x185da7100 _pthread_wqthread + 1096 
    11 libsystem_pthread.dylib  0x185da6cac start_wqthread + 4 

スタック

Answer 1

私は、データアプリケーションのクラッシュが、ランタイムの間違った機能のために起こると想定しました。関数を変更した後、私はもはやアプリケーションのクラッシュを持っていません。

private var queuesKey = 0 
private var referencesKey = 1 

extension UIViewController { 

    var firQueues: [DatabaseQuery]? { 
     get { 
      return objc_getAssociatedObject(self, &queuesKey) as? [DatabaseQuery] 
     } 
     set { 
      objc_setAssociatedObject(self, &queuesKey, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN) 
     } 
    } 

    var firReferences: [DatabaseReference]? { 
     get { 
      return objc_getAssociatedObject(self, &referencesKey) as? [DatabaseReference] 
     } 
     set { 
      objc_setAssociatedObject(self, &referencesKey, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN) 
     } 
    } 


    func removeFIRQueuesReferensesObservers() { 
     if var _firQueues = firQueues { 
      for firQueqry in _firQueues { 
       firQueqry.removeAllObservers() 
      } 
//   debugPrint("removeFIRQueuesReferensesObservers _firQueues start", _firQueues.count, "firQueues", firQueues?.count ?? "nil") 
      _firQueues.removeAll() 
      firQueues?.removeAll() 
//   debugPrint("removeFIRQueuesReferensesObservers _firQueues end", _firQueues.count, "firQueues", firQueues?.count ?? "nil") 
     } 

     if var _firReferences = firReferences { 
      for firRef in _firReferences { 
       firRef.removeAllObservers() 
      } 
//   debugPrint("removeFIRQueuesReferensesObservers _firReferences start", "_firReferences", _firReferences.count, "firReferences", firReferences?.count ?? "nil") 
      _firReferences.removeAll() 
      firReferences?.removeAll() 
//   debugPrint("removeFIRQueuesReferensesObservers _firReferences end", "_firReferences", _firReferences.count, "firReferences", firReferences?.count ?? "nil") 
     } 
    } 

}