php concurrent use of test data curl_ *

When a work experience data concurrency issues, because there is no test data concurrency, when sometimes lead to poor network leading to duplication of data into the database before the line, so the use of curl_ * wrote a special function test data concurrent test case, as follows:

    function test(string $url){

        arr_ch $ = Array ();
         // Create a batch cURL handle 
        $ MH = curl_multi_init ();
         $ index = 0 ;
         the while ( $ index <20 is ) {
            
            CH $ = curl_init ();
             $ arr_ch [ $ index ] = $ CH ; 
　　　　　　　// url provided
            curl_setopt($arr_ch[$index], CURLOPT_URL, $url)；
            curl_setopt ( $ arr_ch [ $ index ], CURLOPT_HEADER, 0 ); 
　　　　　　　// set the required landing sessionid
            curl_setopt($arr_ch[$index] , CURLOPT_COOKIE , "PHPSESSID=vj8qsrag5g6d2dh2t23nv03f11; qlpagecookieid=2dd06ed033d929e8cb4287c622e98275");
            curl_multi_add_handle($mh , $arr_ch[$index]);
            $index++;
            
        }

        // predefined state variable 
        $ Active = null ;

        // perform batch 
        do {
             $ MRC = curl_multi_exec ( $ MH , $ Active );
        } while ($mrc == CURLM_CALL_MULTI_PERFORM);

        while ($active && $mrc == CURLM_OK) {
            if (curl_multi_select($mh) != -1) {
                do {
                    $mrc = curl_multi_exec($mh, $active);
                } while ($mrc == CURLM_CALL_MULTI_PERFORM);
            }
        }

        // Close the respective handle 
        the foreach ( $ arr_ch  AS  $ CH ) {
            curl_multi_remove_handle($mh, $ch);
        }
        curl_multi_close($mh);
    }