On Wed, Aug 10, 2016 at 12:52 PM, Christoph M. Becker <cmbecke...@gmx.de> wrote:
> Hi! > > I've tried to fix <https://bugs.php.net/72793>, and it looks like > there's a general GC issue wrt. to resources referencing objects and > vice versa. Aren't resource ZVALS put in the root buffer? > > See <https://3v4l.org/JYIQs>, which demonstrates the issue better than > the test script in the bug report. A steady increase of allocated > memory can be seen, even though gc_collect_cycles() is called. When > uncommenting `unset($this->parser);`, everything is fine (the GC > wouldn't be involved at all in this case). > > Wrt. to the PHP 5.6 behavior: this appears fine, but actually it's in > error, because of <https://github.com/php/php-src/commit/72ec2e8f>. Not > increasing the refcount of `parser->object` might theoretically lead to > use-after-free scenarios. > As you correctly deduced, we currently do not support GC for resources. This would require introducing something akin to the get_gc handler for resources. The simplest way to fix ext/xml in particular is probably to migrate it to use an object instead of a resource. Nikita
