curl 设置超时，否则会阻塞

    curl_easy_setopt(priv->curl_handle, CURLOPT_URL, access->url);
    curl_easy_setopt(priv->curl_handle, CURLOPT_HEADERFUNCTION, GetContentInfo);
    curl_easy_setopt(priv->curl_handle, CURLOPT_HEADERDATA, (void*)priv);

    if(strncmp(access->url , this_proto_2 , strlen(this_proto_2)) == 0)
    {
        //for https , we will ignore the CA
        curl_easy_setopt(priv->curl_handle, CURLOPT_SSL_VERIFYPEER, 0L);
    }

    
      //curl_easy_setopt(priv->curl_handle, CURLOPT_NOBODY, 0L);
    
    curl_easy_setopt(priv->curl_handle, CURLOPT_WRITEFUNCTION, WriteCallback);
    
    curl_easy_setopt(priv->curl_handle , CURLOPT_TIMEOUT_MS , 5000);
    curl_easy_setopt(priv->curl_handle, CURLOPT_WRITEDATA, (void *)priv);
    curl_easy_setopt(priv->curl_handle, CURLOPT_USERAGENT, "libcurl-agent/1.0");

curl_easy_setopt(priv->curl_handle , CURLOPT_TIMEOUT_MS , 5000);