This overrides the Thread.run method.

    This method checks in an endless loop if new tasks are available
    in the queue and processes them.

def run(self):
    """This overrides the Thread.run method.

    This method checks in an endless loop if new tasks are available
    in the queue and processes them.
    """
    while True:
      if self.pool.name:
        self.idle = True

      try:
        # Wait 60 seconds for a message, otherwise exit. This ensures that the
        # threadpool will be trimmed down when load is light.
        task = self._queue.get(timeout=60)

        if self.pool.name:
          self.idle = False

        try:
          # The pool told us to quit, likely because it is stopping.
          if task == STOP_MESSAGE:
            return

          self.ProcessTask(*task)
        finally:
          self._queue.task_done()

      except queue.Empty:
        if self._RemoveFromPool():
          return

      # Try to trim old threads down when they get too old. This helps the
      # thread pool size to shrink, even when it is not idle (e.g. if it is CPU
      # bound) since threads are forced to exit, but new threads will not be
      # created if the utilization is too high - resulting in a reduction of
      # threadpool size under CPU load.
      if time.time() - self.started > 600 and self._RemoveFromPool():
        return