title: What is fast path, slow path, hot path
body: <p>I've been reading Go source code for a while , there are three terms which is <code>fast path</code>,<code>slow path</code>, <code>hot path</code> comes up a lot.</p>
  <ul>
  <li>fast path : <a href="https://cs.opensource.google/search?q=%22fast%20path%22&amp;ss=go%2Fgo" rel="nofollow noreferrer">https://cs.opensource.google/search?q=%22fast%20path%22&amp;ss=go%2Fgo</a></li>
  <li>slow path : <a href="https://cs.opensource.google/search?q=%22slow%20path%22&amp;ss=go%2Fgo" rel="nofollow noreferrer">https://cs.opensource.google/search?q=%22slow%20path%22&amp;ss=go%2Fgo</a></li>
  <li>hot path : <a href="https://cs.opensource.google/search?q=%22hot%20path%22&amp;ss=go%2Fgo" rel="nofollow noreferrer">https://cs.opensource.google/search?q=%22hot%20path%22&amp;ss=go%2Fgo</a></li>
  </ul>
  <p>So, my question is, what exactly is <code>fast path</code>,<code>slow path</code>, <code>hot path</code> ? Are these terms unique to Go ?</p>