title: What does it mean if get_ident() returns the same value?
body: <p>If <code>get_ident()</code> returns the same value during the execution of a program, does that mean the thread is the same thread, or is it possible that the thread was restarted but got the same identifier as a previous thread?</p>
  
  <p>If it is possible, how likely is it - pretty likely?</p>
  
  <p>I ask because I expected a particular Thread subclass to be killed and restarted multiple times during a program, and only one instance of that subclass running as a thread at a time. But, I made those threads log their thread id returned by <code>get_ident()</code> occasionally, and I saw that it was pretty common for some ids to re-occur, even after a different id was logged after the first occurrence.</p>