Bug #81113 [Opn]: PDO holds some non-GCable reference

Edit report at https://bugs.php.net/bug.php?id=81113&edit=1 ID: 81113 Updated by: nikic@php.net Reported by: m at m dot cz Summary: PDO holds some non-GCable reference Status: Open Type: Bug Package: PDO related Operating System: any PHP Version: 8.0.7 Block user comment: N Private report: N New Comment: I tried this script https://gist.github.com/nikic/a55b70d6b7c1acf6785c7e50c37754dc based on the dbal issue, but it does not show a memory leak on PHP 8.1 (or PHP 8.0, or PHP 7.4). So whatever issue that hit, it seems to have been fixed. The memory leak reported in bug #75190 is also fixed. If there is some reasonably minimal way to reproduce, I'm happy to address other GC problems as well. I don't want to reduce this down from "using doctrine dbal, somewhere, somehow" though. Previous Comments: ------------------------------------------------------------------------ [2021-06-08 12:31:53] m at m dot cz It seems it is related with: https://github.com/doctrine/dbal/issues/3047 and https://bugs.php.net/bug.php?id=75190 which describes a GC issue when PDO class is extended, hovewer, it is marked as "not a bug". Why it is not a bug or is it technically impossible to provide full GC support? ------------------------------------------------------------------------ [2021-06-08 11:52:05] nikic@php.net Okay, I think this will need some more reduced code to make progress. PDO generally does support GC, and since PHP 8.1 also supports per-driver GC. So this probably requires that some specific feature is being used. ------------------------------------------------------------------------ [2021-06-08 09:31:44] m at m dot cz At least pdo_mysql is affected, as when max. connection count is limited (by ALTER USER user@% WITH MAX_USER_CONNECTIONS 10;), connection limit is hit. ------------------------------------------------------------------------ [2021-06-08 08:52:19] nikic@php.net Which PDO driver do you use? ------------------------------------------------------------------------ [2021-06-08 08:46:32] m at m dot cz working link https://github.com/atk4/data/commit/83345e3ce4b9006efe9bfe50befacef20f3aee08 ------------------------------------------------------------------------ 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=81113 -- Edit this bug report at https://bugs.php.net/bug.php?id=81113&edit=1