EXC_BAD_ACCESS Code=2 Swift iOS - ios

Question

When developing an iOS app I come across random (sometimes occurring, sometimes not) EXC_BAD_ACCESS error in the following code:
import UIKit
class OrderTripDetailsController: UIViewController, OrderAware {
var order: Order?
var orderService = OrderService()
// MARK: Properties
#IBOutlet weak var driverName: UILabel!
#IBOutlet weak var autoColor: UILabel!
#IBOutlet weak var autoPlates: UILabel!
#IBOutlet weak var autoBrandModel: UILabel!
#IBOutlet weak var map: YMKMapView!
// MARK: Actions
// MARK: Navigation
override func viewDidLoad() {
if let cab = order?.orderCab {
autoColor.text = cab.cab.auto.color.name
autoPlates.text = cab.cab.auto.plates
driverName.text = cab.cab.driver.fullname
autoBrandModel.text = "\(cab.cab.auto.brand) \(cab.cab.auto.model)"
}
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
orderService.controllerDelegate = self
orderService.startSync()
}
override func viewWillDisappear(animated: Bool) {
orderService.stop() // <-- this is the line that fails
super.viewWillDisappear(animated)
}
// MARK: Order Aware
func setOrder(order: Order){
self.order = order
}
}
OrderService
Order Service is a class that starts timer and stops it. After stop is called, sometimes EXC_BAD_ACCESS occurs
import Locksmith
import RealmSwift
class OrderService {
// MARK: delegates
var controllerDelegate: UIViewController?
// Get the default Realm
let realm = try! Realm()
var timer = NSTimer()
//MARK: Domain actions
//repeat every n time if any dfound
#objc func initOrderSync(timer:NSTimer) {
func onRemoteReceived (order: Order) -> Void {
debugPrint("remote received", order.id)
if let o = realm.objectForPrimaryKey(OrderPo.self, key: order.orderHash) {
if o.orderStatus != order.orderStatus {
debugPrint("order status updated", order.id, order.orderStatus)
OrderUtils.navigateToOrderStatus(order,
viewController: controllerDelegate!)
}
try! realm.write {
o.orderStatus = order.orderStatus
}
}
}
if let authToken = AuthUtils.getToken() {
let orders = getOrdersByStatuses(OrderUtils.activeStatuses)
if orders.count > 0 {
for o in orders {
OrderRemoteService().getOrderFromRemote(o.id!, token: authToken, callback: onRemoteReceived)
}
} else {
debugPrint("invalidating timer; no orders")
stop()
}
} else {
debugPrint("invalidating timer; no auth")
stop()
}
}
func startSync() {
if !self.timer.valid {
debugPrint("starting order sync", controllerDelegate?.restorationIdentifier)
self.timer = NSTimer.scheduledTimerWithTimeInterval(20, target: self, selector: Selector("initOrderSync:"), userInfo: nil, repeats: true)
} else {
debugPrint("sync is already started", controllerDelegate?.restorationIdentifier)
}
}
func stop() {
dispatch_async(GlobalMainQueue, {
if self.timer.valid {
self.timer.invalidate()
debugPrint("invalidated timer", self.controllerDelegate?.restorationIdentifier)
} else {
debugPrint("sync is already stopped", self.controllerDelegate?.restorationIdentifier)
}
})
}
// MARK: orders
func getOrders() -> Results<OrderPo> {
return try! realm.objects(OrderPo.self).sorted("orderTime")
}
func getOrdersByStatuses(statuses: [String]) -> Results<OrderPo> {
var qString = "'\(statuses.first!)'"
if statuses.count > 1 {
for s in 1...statuses.count-1 {
qString += ",'\(statuses[s])'"
}
}
return try! realm.objects(OrderPo.self).filter("orderStatus IN {\(qString)}").sorted("orderTime")
}
}
Could anyone help with any ideas why it might happen?
Update 20.08.2016
Found out that OrderService is being deinitialised after 10 seconds for some reason.