Doc #61141 [Nab]: curl_multi_select returns -1

Edit report at https://bugs.php.net/bug.php?id=61141&edit=1 ID: 61141 Updated by: pierrick@php.net Reported by: amoo_miki at yahoo dot com Summary: curl_multi_select returns -1 Status: Not a bug Type: Documentation Problem Package: cURL related Operating System: Windows 7 x64 PHP Version: 5.3.10 Assigned To: pierrick Block user comment: N Private report: N New Comment: The change that introduced your problem is somewhere in libcurl. You could submit a bug to libcurl, but I'm pretty sure they will come with the same answer as I did since it's documented. I know that the code will work even if you never call curl_multi_select but I would recommend you to use it anyway to make sure you'll not consume all your cpu resources and I would follow the libcurl recommandation to sleep some time before executing the curl_multi_exec Previous Comments: ------------------------------------------------------------------------ [2012-09-22 14:03:06] amoo_miki at yahoo dot com i reread your comment about The libcurl documentations says "When max_fd returns with -1, you need to wait a while and then proceed and call curl_multi_perform anyway"... ... the keyword being "anyway". ------------------------------------------------------------------------ [2012-09-22 13:56:43] amoo_miki at yahoo dot com Gotcha. The code change you propose works, but not sure why it doesn't make sense to me. while ($active && $mrc == CURLM_OK) { do { $mrc = curl_multi_exec($mh, $active); } while ($mrc == CURLM_CALL_MULTI_PERFORM); } The above piece works too, without needing the timeout, but that mean skipping the curl_multi_select altogether, practically what you found is that we can do without checking curl_multi_select which doesn't solve the problem with curl_multi_select. See where i am going? Also, thanks for looking into this. curl_multi_select is a very useful function and it would be crazy not to use it. ------------------------------------------------------------------------ [2012-09-22 13:49:52] amoo_miki at yahoo dot com I should also add that, the sample code, without the sleep works perfectly fine on non-windows setups. I verified it using 5.3.13 which uses cURL 7.24.0 on OSX. ------------------------------------------------------------------------ [2012-09-22 13:44:50] pierrick@php.net No, sorry if I was unclear. The libcurl documentations says "When max_fd returns with -1, you need to wait a while and then proceed and call curl_multi_perform anyway". If you translate this in PHP (That was where I was unclear) : "When curl_multi_select returns with -1, you need to wait a while and then proceed and call curl_multi_exec anyway" Then, you should have something like this : while ($active && $mrc == CURLM_OK) { if (curl_multi_select($mh) == -1) usleep(100); do { $mrc = curl_multi_exec($mh, $active); } while ($mrc == CURLM_CALL_MULTI_PERFORM); } ------------------------------------------------------------------------ [2012-09-22 13:38:44] amoo_miki at yahoo dot com I modified the script and put a sleep(10) and it still doesn't work. Here is the script i used; was this what you meant? <?php $ch1 = curl_init(); $ch2 = curl_init(); curl_setopt($ch1, CURLOPT_URL, "http://windows.php.net/downloads/releases/md5sum.txt"); curl_setopt($ch1, CURLOPT_HEADER, 0); curl_setopt($ch1, CURLOPT_RETURNTRANSFER, 1); curl_setopt($ch2, CURLOPT_URL, "http://windows.php.net/downloads/releases/sha1sum.txt"); curl_setopt($ch2, CURLOPT_HEADER, 0); curl_setopt($ch2, CURLOPT_RETURNTRANSFER, 1); $mh = curl_multi_init(); curl_multi_add_handle($mh,$ch1); curl_multi_add_handle($mh,$ch2); $active = null; 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); else { echo "* Sleeping for 10 secs\n"; sleep(10); } } echo strlen(curl_multi_getcontent($ch1))."-".strlen(curl_multi_getcontent($ch2)); curl_multi_remove_handle($mh, $ch1); curl_multi_remove_handle($mh, $ch2); curl_multi_close($mh); ?> ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=61141 -- Edit this bug report at https://bugs.php.net/bug.php?id=61141&edit=1