如何防止cURL在一个可湿性粉剂函数中被触发两次？

<?php
class CurlWrapper {
    private static $mutex;

    public static function curlRequest($url) {
        if (!self::$mutex) {
            self::$mutex = curl_multi_init();
        }

        // 加锁
        curl_multi_add_handle(self::$mutex, curl_init($url));

        // 执行cURL请求
        do {
            curl_multi_exec(self::$mutex, $running);
        } while ($running > 0);

        // 移除handle并关闭cURL
        curl_multi_remove_handle(self::$mutex, curl_multi_gethandle(self::$mutex));
        curl_multi_close(self::$mutex);

        // 解锁
        self::$mutex = null;
    }
}

// 调用示例
CurlWrapper::curlRequest('https://example.com');
?>