Bug #74297 [Opn->Csd]: Corruption of interned string cache leads to random behaviour

Edit report at https://bugs.php.net/bug.php?id=74297&edit=1 ID: 74297 Updated by: kelunik@php.net Reported by: arjen at parse dot nl Summary: Corruption of interned string cache leads to random behaviour -Status: Open +Status: Closed Type: Bug Package: opcache Operating System: Linux PHP Version: 7.1.3 -Assigned To: +Assigned To: kelunik Block user comment: N Private report: N New Comment: Fixed, see https://github.com/php-memcached-dev/php-memcached/issues/338. Previous Comments: ------------------------------------------------------------------------ [2017-05-16 23:37:51] aaron at serendipity dot cx As the maintainer of php-memcached extension: I am not able to reproduce the problem with PHP 7.0.17 on Mac OS X. I *can* reproduce the problem with PHP 7.1.3 on Mac OS X. Who can help me understand what changedPHP 7.0 -> 7.1 that might be causing this problem? ------------------------------------------------------------------------ [2017-04-25 10:02:26] arjen at parse dot nl When the interned string cache buffer is configured to 0, everything works fine: php -n -dextension=memcached.so -dzend_extension=opcache.so -dopcache.interned_strings_buffer=0 test.php ------------------------------------------------------------------------ [2017-04-25 10:01:26] arjen at parse dot nl Also reported @ https://github.com/php-memcached-dev/php-memcached/issues/338 ------------------------------------------------------------------------ [2017-03-23 11:03:17] arjen at parse dot nl Test script sometimes does not fail on first run, so please try a few times.. ------------------------------------------------------------------------ [2017-03-23 11:01:35] arjen at parse dot nl Description: ------------ php-memcached 3.0.3 libmemcached 1.0.18 memcached 1.4.32 php 7.1.3 Both memcached and opcache needs to be loaded. opcache.enable_cli is not needed. php -n -dextension=memcached.so -dzend_extension=opcache.so script.php If the value ('test') set in memcached is changed, the script no longer fails. ($e == $a) === false, while ($a == $e) === true... Test script: --------------- <?php class r { public $d = ['test' => 'x']; public function m() { return [] + $this->d; } } (function() { $m = new memcached; $m->addServer('127.0.0.1', 11211); $m->set('Something', 'test'); $e = ['test' => 'x']; $a = (new r)->m(); if (0 == ($e <=> $a)) return 'success'; var_dump([$e, $a]); var_dump([serialize($e), serialize($a)]); var_dump([ 'e === a' => $e === $a, 'e == a' => $e == $a, 'e <=> a' => $e <=> $a, 'a <=> e' => $a <=> $e, 'a === e' => $a === $e, 'a == e' => $a == $e] ); var_dump(debug_zval_dump($e), debug_zval_dump($a)); die('this should not happen'); })(); Expected result: ---------------- success Actual result: -------------- array(2) { [0]=> array(1) { ["test"]=> string(1) "x" } [1]=> array(1) { ["test"]=> string(1) "x" } } array(2) { [0]=> string(25) "a:1:{s:4:"test";s:1:"x";}" [1]=> string(25) "a:1:{s:4:"test";s:1:"x";}" } array(6) { ["e === a"]=> bool(true) ["e == a"]=> bool(false) ["e <=> a"]=> int(1) ["a <=> e"]=> int(0) ["a === e"]=> bool(true) ["a == e"]=> bool(true) } array(1) refcount(1){ ["test"]=> string(1) "x" refcount(1) } array(1) refcount(2){ ["test"]=> string(1) "x" refcount(1) } ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=74297&edit=1