code: def gc_stop():
      
      global gc_thread
      
      if gc_thread:
          log.info("Shutting down GC thread")
          gc_thread.signal_stop()
          gc_thread.join()
          log.info("GC thread joined")
          gc_thread = None
      else:
          log.info("GC thread already joined")
docs: Stop a the optimistic GC thread