libcurl 异步调用curl_multi_fdset max_fd总返回-1

libcurl异步调用的总返回curl_multi_fdset max_fd -1 libcurl异步调用的总返回curl _ multi _ FD set max _ FD-1简介:CURLM * multi _ handle = NULLmulti _ handle = curl _ multi _ init()；//添加到multi stackcurl _ multi _ add _ handle(m