Question

I’m having trouble creating multiple xml requests using php’s curl_multi_exec.

The problem is that the do…while loop containing the curl_multi_exec command runs only once and then quits.

Resources Used:

http://www.phpied.com/simultaneuos-http-requests-in-php-with-curl/
http://php.net/manual/en/function.curl-multi-exec.php/
http://www.rustyrazorblade.com/2008/02/curl_multi_exec/

Take a look at my code:

    //Multi handle curl initialization
    $mh = curl_multi_init();

    //set url
    $url = 'my_url';

    foreach($latLng as $id => $l) {
        $ch[$id] = curl_init();

        //$request previously set                

        //Initialize and set options 
        curl_setopt($ch, CURLOPT_URL,                $url);
        curl_setopt($ch, CURLOPT_HEADER,             0);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER,     1);
        curl_setopt($ch, CURLOPT_POST,               1);
        curl_setopt($ch, CURLOPT_POSTFIELDS,        $request); 

        //add to multi_handle
        curl_multi_add_handle($mh, $ch[$id]);
    }

    //Execute the handles
    $running = null;

    do {
        $mrc = curl_multi_exec($mh, $running);   
        $ready=curl_multi_select($mh);
        echo "Ran once\n";
    } while ($mrc == CURLM_CALL_MULTI_PERFORM && $ready > 0);

    while ($active && $mrc == CURLM_OK) {
        if ($curl_multi_select($mh) != -1) {
            do {
                $mrc = curl_multi_exec($mh, $running);
                echo "Ran again\n";
            } while ($mrc == CURLM_CALL_MULTI_PERFORM);
        }
    }

    foreach ($mh as $c) {
        // HTTP response code
        $code = curl_getinfo($c,  CURLINFO_HTTP_CODE);

        // cURL error number
        $curl_errno = curl_errno($c);

        // cURL error message   
        $curl_error = curl_error($c);

        // output if there was an error                                                            
        if ($curl_error) {
            echo("*** cURL error: ($curl_errno) $curl_error\n");
        }
    }

    //get content and remove handles
    foreach ($ch as $c) {
        $result[] = curl_multi_getcontent($c);  
        curl_multi_remove_handle($mh, $c);  
    }   

    print_r($result);

    //Close curl
    curl_multi_close($mh);
}

I know the request is valid because I receive the correct return data when I perform a single curl execution. The problem lies with the curl_multi_exec().

The output I am receiving is “Ran once” followed by the empty arrays of the curl_multi_getcontent() calls. See below:

Ran once
Array
(
[0] =>
[1] =>
[2] =>
[3] =>
[4] =>
[5] =>
[6] =>
[7] =>
[8] =>
)

Any help is greatly appreciated.

Answer 1

You’re not setting up the curl options correctly:

Currently, you’re setting options on $ch which is your array, you need to be setting the options specifically on the current curl handler, which in your loop is $ch[$id]:

   //Initialize and set options 
   curl_setopt($ch[$id], CURLOPT_URL,                $url);
   curl_setopt($ch[$id], CURLOPT_HEADER,             0);
   curl_setopt($ch[$id], CURLOPT_RETURNTRANSFER,     1);
   curl_setopt($ch[$id], CURLOPT_POST,               1);
   curl_setopt($ch[$id], CURLOPT_POSTFIELDS,        $request);