public function flush()
    {
        if (!empty($this->cacheListing)) {
            foreach ($this->cacheListing as $entry) {
                /** @var $entry Entry */
                if ($entry instanceof Entry) {
                    $entry->delete();
                }
            }

            $this->cacheListing = array();
        }


        @shmop_delete($this->indexIdentifier);

        return true;
    }