// Loop infinitely, processing all service updates provided by the queue.
func (s *ServiceController) watchServices(serviceQueue *cache.DeltaFIFO) {
	for {
		serviceQueue.Pop(func(obj interface{}) error {
			deltas, ok := obj.(cache.Deltas)
			if !ok {
				runtime.HandleError(fmt.Errorf("Received object from service watcher that wasn't Deltas: %+v", obj))
				return nil
			}
			delta := deltas.Newest()
			if delta == nil {
				runtime.HandleError(fmt.Errorf("Received nil delta from watcher queue."))
				return nil
			}
			err, retryDelay := s.processDelta(delta)
			if retryDelay != 0 {
				// Add the failed service back to the queue so we'll retry it.
				runtime.HandleError(fmt.Errorf("Failed to process service delta. Retrying in %s: %v", retryDelay, err))
				go func(deltas cache.Deltas, delay time.Duration) {
					time.Sleep(delay)
					if err := serviceQueue.AddIfNotPresent(deltas); err != nil {
						runtime.HandleError(fmt.Errorf("Error requeuing service delta - will not retry: %v", err))
					}
				}(deltas, retryDelay)
			} else if err != nil {
				runtime.HandleError(fmt.Errorf("Failed to process service delta. Not retrying: %v", err))
			}
			return nil
		})
	}
}
// Loop infinitely, processing all service updates provided by the queue.
func (s *ServiceController) watchServices(serviceQueue *cache.DeltaFIFO) {
	for {
		newItem := serviceQueue.Pop()
		deltas, ok := newItem.(cache.Deltas)
		if !ok {
			glog.Errorf("Received object from service watcher that wasn't Deltas: %+v", newItem)
		}
		delta := deltas.Newest()
		if delta == nil {
			glog.Errorf("Received nil delta from watcher queue.")
			continue
		}
		err, shouldRetry := s.processDelta(delta)
		if shouldRetry {
			// Add the failed service back to the queue so we'll retry it.
			glog.Errorf("Failed to process service delta. Retrying: %v", err)
			time.Sleep(processingRetryInterval)
			serviceQueue.AddIfNotPresent(deltas)
		} else if err != nil {
			util.HandleError(fmt.Errorf("Failed to process service delta. Not retrying: %v", err))
		}
	}
}