curl_multi_close
> replying to viczbk.ru
Just sharing my attempt at it.
> while (($res = curl_multi_select($mh)) === 0) {};
This worked on my windows computer (php 5.2.5) but when I ran the curl program in my new centOS server (php 5.1.6) the function never updates unless curl_multi_exec() is added to the loop, taking away the point of using it to save cycles. curl_multi_select() also allows you to set a timeout but it doesn't seem to help, then again, don't see why people wouldn't use it anyway.
Even when curl_multi_select($mh) does work there's no way to know which of the sockets updated in status or if they've received partial data, completely finished, or just timed out. It's not reliable if you want to remove / add data as soon as things finish. Try calling just example.com or some other website with very little data. curl_multi_select($mh) can send non 0 value a couple of thousand times before finishing. Lazily adding a usleep(25000) or some minimal amount can also help not waste cycles.
curl_multi_exec
(PHP 5)
curl_multi_exec — Exécute les sous-requêtes de la session cURL
Description
int curl_multi_exec
( resource $mh
, int &$still_running
)
Exécute chaque gestionnaire de la pile. Cette méthode peut être appelée même si un gestionnaire à besoin de lire ou d'écrire des données.
Liste de paramètres
- mh
-
Un gestionnaire cURL multiple retourné par la fonction curl_multi_init().
- still_running
-
Une référence à un drapeau, qui annonce si les opérations sont toujours en cours.
Valeurs de retour
Un code cURL, défini dans les constantes prédéfinies cURL.
Note: Cette fonction retourne que des erreurs au regard de la pile. Des problèmes surviennent toujours sur des transferts individuels même lorsque cette fonction retourne CURLM_OK.
Exemples
Exemple #1 Exemple avec curl_multi_exec()
Cet exemple crée deux gestionnaires cURL, les ajoute à un gestionnaire multiple, et les exécute en parallèle.
<?php
// Création des ressources cURL
$ch1 = curl_init();
$ch2 = curl_init();
// Définit l'URL ainsi que d'autres options
curl_setopt($ch1, CURLOPT_URL, "http://lxr.php.net/");
curl_setopt($ch1, CURLOPT_HEADER, 0);
curl_setopt($ch2, CURLOPT_URL, "http://www.php.net/");
curl_setopt($ch2, CURLOPT_HEADER, 0);
// Création du gestionnaire multiple
$mh = curl_multi_init();
// Ajoute les deux gestionnaires
curl_multi_add_handle($mh,$ch1);
curl_multi_add_handle($mh,$ch2);
$active = null;
// Exécute le gestionnaire
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);
}
}
// Ferme les gestionnaires
curl_multi_remove_handle($mh, $ch1);
curl_multi_remove_handle($mh, $ch2);
curl_multi_close($mh);
?>
add a note
User Contributed Notescurl_multi_exec
Jimmy Ruska
13-Sep-2008 08:56
13-Sep-2008 08:56
viczbk.ru
09-Feb-2008 05:04
09-Feb-2008 05:04
http://curl.haxx.se/libcurl/c/libcurl-multi.html
"When you've added the handles you have for the moment (you can still add new ones at any time), you start the transfers by call curl_multi_perform(3).
curl_multi_perform(3) is asynchronous. It will only execute as little as possible and then return back control to your program. It is designed to never block. If it returns CURLM_CALL_MULTI_PERFORM you better call it again soon, as that is a signal that it still has local data to send or remote data to receive."
So it seems the loop in sample script should look this way:
<?php
$running=null;
//execute the handles
do {
while (CURLM_CALL_MULTI_PERFORM === curl_multi_exec($mh, $running));
if (!$running) break;
while (($res = curl_multi_select($mh)) === 0) {};
if ($res === false) {
echo "<h1>select error</h1>";
break;
}
} while (true);
?>
This worked fine (PHP 5.2.5 @ FBSD 6.2) without running non-blocked loop and wasting CPU time.
However this seems to be the only use of curl_multi_select, coz there's no simple way to bind it with other PHP wrappers for select syscall.
robert dot reichel at boboton dot com
20-Oct-2007 02:54
20-Oct-2007 02:54
I was testing PHP code provided by dtorop933@gmail.com in curl_multi_exec section of PHP Manual.
The part of the code '$err = curl_error($conn[$i])' should return error message for each cURL session, but it does not.
The function curl_error() works well with the curl_exec(). Is there any other solution for getting session error message with curl_multi_exec() or there is a bug in cURL library.
The script was tested with Windows XP and PHP-5.2.4
shichuanr at gmail dot com
06-Sep-2007 02:12
06-Sep-2007 02:12
For people who have problem running the above example script(Example 425. curl_multi_exec()), you can alter it a little bit to make it work properly by replacing the existing chunk of code with the one below:
<?php
// create both cURL resources
$ch1 = curl_init();
$ch2 = curl_init();
// set URL and other appropriate options
curl_setopt($ch1, CURLOPT_URL, "http://www.google.com/");
curl_setopt($ch1, CURLOPT_HEADER, 0);
curl_setopt($ch2, CURLOPT_URL, "http://www.php.net/");
curl_setopt($ch2, CURLOPT_HEADER, 0);
//create the multiple cURL handle
$mh = curl_multi_init();
//add the two handles
curl_multi_add_handle($mh,$ch1);
curl_multi_add_handle($mh,$ch2);
$running=null;
//execute the handles
do {
curl_multi_exec($mh,$running);
} while ($running > 0);
//close the handles
curl_multi_remove_handle($mh,$ch1);
curl_multi_remove_handle($mh,$ch1);
curl_multi_close($mh);
?>
substr("iscampifriese",1,11) dot " at beer dot com"
04-Jul-2007 03:10
04-Jul-2007 03:10
If you are using mulit handles and you wish to re-execute any of them (if they timed out or something), then you need to remove the handles from the mulit-handle and then re-add them in order to get them to re-execute. Otherwise cURL will just give you back the same results again without actually retrying.