title: ThreadLocal & Memory Leak
body: <p>It is mentioned at multiple posts: improper use of <code>ThreadLocal</code> causes Memory Leak. I am struggling to understand how Memory Leak would happen using <code>ThreadLocal</code>. </p>
  
  <p>The only scenario I have figured out it as below:</p>
  
  <blockquote>
    <p>A web-server maintains a pool of Threads (e.g. for servlets). Those threads can create memory leak if the variables in <code>ThreadLocal</code> are not removed because Threads do not die.</p>
  </blockquote>
  
  <p>This scenario does not mention "Perm Space" memory leak. Is that the only (major) use case of memory leak? </p>