title: Does thread pool size keep growing for scheduledthreadpoolexecutor?
body: <p>Imagine a situation where tasks are being added to scheduledthreadpoolexecutor. Each of these tasks will keep on running at different periodic intervals.</p>
  
  <p>Although all such tasks will not be running at the same time because each is set at different intervals, there may be a situation where a high number of threads are competing for execution.  </p>
  
  <p>Is there any restriction on total number of threads ? It seems there is a restriction on the total number of <b>idle</b> threads. And does this concept of idle thread imply that long running tasks (thread) may be destroyed and recreated when needed ?</p>