PHP警告：stream\u socket\u sendto（）：管道破裂

我已经为我的php脚本实现了外部类，它调用了以下警告：

PHP警告：stream\u socket\u sendto（）：管道破裂

参考代码：

    /**
     * writes the contents of string to the file stream pointed to by handle 
     * If an error occurs, returns FALSE.
     * @access protected
     * @param string $string The string that is to be written
     * @return string Returns a result code, as an integer. 
     */
    protected function _streamQuery($query) {
        $this->edebug($query);
        return stream_socket_sendto($this->stream, $query . self::CRLF);
    }

如何解决这个警告