SpringboardDestroyer. Too many background tasks make Frontboard very sad. See http://openradar.appspot.com/32482871

SpringboardDestroyer.swift

let badwork = { (queue: DispatchQueue) in
    queue.async {
        let app = UIApplication.shared

        for index in 0..<100000 {

            let name = "Yolo \(index)"
            let identifier = app.beginBackgroundTask(withName: name, expirationHandler: {
                print("Expired")
            });
            print("Started \(identifier)")

            let time = DispatchTime.now() + Double(arc4random_uniform(1000))/10.0
            queue.asyncAfter(deadline: time, execute: {
                app.endBackgroundTask(identifier)
                print("Ended \(identifier)")
            })
        }
    }
}

let userQueue = DispatchQueue.global(qos: .userInitiated)
badwork(userQueue)

let defaultQueue = DispatchQueue.global(qos: .default)
badwork(defaultQueue)

let interactiveQueue = DispatchQueue.global(qos: .userInteractive)
badwork(interactiveQueue)