title: swift - how to prevent two touches at the same time
body: <p>For example, I have 2 buttons <code>Change email</code> and <code>Change password</code>, and each of them call functions with Alamofire request, and responce data should reload both the UI and data scheme.</p>
  
  <p>The point is that this PUT requests change not only servers's data, but generate new token and get updated user's profile. </p>
  
  <p>And when pressing buttons at the same time, at the same moment touches begin and end, app crash after parsing requests.</p>
  
  <p>I'm blocking another UI elements(like textfields), I was trying to block another button, but when press it together, it's not works. </p>
  
  <p>So how can I prevent the same time touch? I'm not good at <code>OperationQueue</code>, maybe thats'the way? Is there an option to check if operation not first at the queue and kill it?</p>