title: How to deal with lag spike from gamecenter
body: <p>My game uses Game Center for scoreboards.  At the start of the app I ask Game Center to login. </p>
  
  <p>The problem is that after a variable amount of time Game Center pops up with its "welcome back...." thing and this creates a HUGE latency spike in my app that is already low on resources.</p>
  
  <p>I have played with the completion handlers trying to find out some sort of callback when the banner is done... but nothing!</p>
  
  <p>How am I supposed to handle this? I have a loading screen, could I perhaps not finish loading until the thing has popped up?</p>
  
  <p>Here is my code I use right now</p>
  
  <pre><code>func authenticateLocalPlayer()
      {
          Holder.loggedIn = false
          print("Start Authenticate")
          let localPlayer = GKLocalPlayer.localPlayer()
          localPlayer.authenticateHandler = {(viewController, error) -&gt; Void in
              if (viewController != nil)
              {
                  self.presentViewController(viewController!, animated: false, completion: {self.authenticated()})
              }
          }
      }
  </code></pre>