def put(self, obj):
        """
        Put the item 'obj' on the queue.
        """
        self.mutex.acquire()
        try:
            self.put_cache.append(obj)
            if len(self.put_cache) >= self.cache_size:
                self._split()
        finally:
            self.mutex.release()

        Put the item 'obj' on the queue.
        
recipes/Python/501154_Persistent_Queue/recipe-501154.py