title: Timers in clojure?
body: <p>I'm wondering if there is any widespread timer solution. </p>
  
  <p>I want to write a simple game engine which would process users input on tick every 20ms (or perform some actions once <em>after</em> 20ms (or any other period)) and basically update "global" state via transactions, and also I plan to use <code>futures</code> so this solution should be able to deal with concurrency caveats.</p>
  
  <p>Can you give me an advice?</p>