Bug #70425 [Com]: Multicurl runs forever with PHP >= 5.6

Edit report at https://bugs.php.net/bug.php?id=70425&edit=1 ID: 70425 Comment by: apringle at gmail dot com Reported by: cyberline@php.net Summary: Multicurl runs forever with PHP >= 5.6 Status: Open Type: Bug Package: cURL related Operating System: Irrelevant PHP Version: 5.6.12 Block user comment: N Private report: N New Comment: I ran into this when testing a PHP 5.6.13 system. However, I then noticed the same behavior happening on a system running PHP 5.5.27. This particular system had a newer version of libcurl installed. Downgrading to the libcurl (7.19) provided by my CentOS distro fixed the behavior. Using the test case provided in the bug report, here are the results from some different platforms I was able to test on: Centos6.6, PHP 5.5.27, libcurl-7.19.7-46: HTML response shown in output Centos6.6, PHP 5.5.27, libcurl-7.29: Hangs until execution timeout Debian8, PHP 5.5.29, libcurl-7.38.0-4: Hangs until execution timeout Debian8, PHP 5.6.13, libcurl-7.38.0-4: Hangs until execution timeout OSX 10.10.5, PHP 5.5.7, libcurl 7.43.0: Hangs until execution timeout Previous Comments: ------------------------------------------------------------------------ [2015-09-04 09:15:33] cyberline@php.net Description: ------------ If you use multicurl simmilar to the sample mentioned here: http://php.net/manual/en/function.curl-multi-init.php your code will run forever or reach max_execution_time. Test script: --------------- <?php // create both cURL resources $ch1 = curl_init(); $ch2 = curl_init(); // set URL and other appropriate options curl_setopt($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); //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); $active = null; //execute the handles 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 handles curl_multi_remove_handle($mh, $ch1); curl_multi_remove_handle($mh, $ch2); curl_multi_close($mh); Expected result: ---------------- HTML of both URL's Actual result: -------------- Nothing happens. strace output shows endless: select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) select(5, [], [4], [], {1, 0}) = 1 (out [4], left {0, 999999}) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=70425&edit=1