Bug #81215 [Opn]: Possible memory leak with closure nested \array_filter()

Edit report at https://bugs.php.net/bug.php?id=81215&edit=1 ID: 81215 User updated by: berliozdavid at gmail dot com Reported by: berliozdavid at gmail dot com Summary: Possible memory leak with closure nested \array_filter() Status: Open Type: Bug Package: Performance problem Operating System: Fedora/Linux PHP Version: 8.0.8 Block user comment: N Private report: N New Comment: I can confirm that php -n is not affected. So far I've tested separately php -n -dextension=swoole.so opcache xhprof No memory leak I can test with a set of common modules if you provide me a list. Previous Comments: ------------------------------------------------------------------------ [2021-07-01 13:20:37] nikic@php.net Thanks! Some of those (e.g. xhprof, swoole) look potentially problematic in terms of modifying engine behavior. Can you please check whether you still see when using "php -n" (i.e. without ini file)? ------------------------------------------------------------------------ [2021-07-01 13:01:35] berliozdavid at gmail dot com [PHP Modules] apcu bz2 calendar Core ctype curl date dom exif fileinfo filter ftp gd gettext hash iconv igbinary imagick inotify intl json libxml mbstring memcached mongodb msgpack mysqli mysqlnd openssl pcntl pcre PDO pdo_mysql pdo_sqlite Phar posix readline redis Reflection session shmop SimpleXML soap sockets SPL sqlite3 ssh2 standard swoole sysvmsg sysvsem sysvshm tokenizer xhprof xml xmlreader xmlwriter xsl Zend OPcache zip zlib [Zend Modules] Zend OPcache ------------------------------------------------------------------------ [2021-07-01 12:55:47] nikic@php.net I can't reproduce this, memory usage is stable for me. Tested with and without opcache. Do you have any interesting extensions like xdebug loaded? ------------------------------------------------------------------------ [2021-07-01 12:42:50] berliozdavid at gmail dot com Using static closure leads to memory leak too: $f = static function ($array) { return \array_filter($array, fn($item) => !is_null($item)); }; ------------------------------------------------------------------------ [2021-07-01 12:37:33] berliozdavid at gmail dot com Description: ------------ With PHP80 using \array_filter() in a closure can lead to memory leak. PHP74 is not affected. Test script: --------------- <?php namespace Somewhere\On\Earth; class Foo { function leaking(array $array) { $f = function ($array) { return \array_filter($array, fn($item) => !is_null($item)); }; for (;;) { $clone = (array) $array; $res = $f($clone); printf("memory: %d\n", \memory_get_usage()); unset($clone, $res); } } function run() { $array = array_combine(range(1, 1000, 2), array_fill(1, 500, null)); $array += array_combine(range(2, 1000, 2), array_fill(1, 500, true)); $this->leaking($array); } } (new Foo())->run(); Expected result: ---------------- stable memory value. Actual result: -------------- increasing memory value. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=81215&edit=1