'Update the configuration values.
This clears the cached values, initializes the registry, and loads
the configuration values from the config module.'

def _update_configs(self):

    self._lock.acquire()
    try:
        if self._initialized:
            self._clear_cache()
        self._registry.initialize()
        for (key, value) in self._registry._pairs(self._prefix):
            if (key not in self._defaults):
                logging.warn('Configuration    "%s"    not    recognized', (self._prefix + key))
            else:
                self._overrides[key] = value
        self._initialized = True
    finally:
        self._lock.release()
