Hprose\Service::addAsyncFunction PHP Method

    public function addAsyncFunction($func, $alias = '', array $options = array())
    {
        if (is_array($alias) && empty($options)) {
            $options = $alias;
            $alias = '';
        }
        $options['async'] = true;
        return $this->addFunction($func, $alias, $options);
    }