Bug #76874 [Asn->Csd]: xml_parser_free() should never leak memory

Edit report at https://bugs.php.net/bug.php?id=76874&edit=1 ID: 76874 Updated by: nikic@php.net Reported by: ksours at internetbrands dot com Summary: xml_parser_free() should never leak memory -Status: Assigned +Status: Closed Type: Bug Package: *XML functions Operating System: * PHP Version: 7.3.0beta3 Assigned To: nikic Block user comment: N Private report: N New Comment: ext/xml has been migrated to use objects in PHP 8, so the issue will be resolved there. Previous Comments: ------------------------------------------------------------------------ [2018-09-17 09:06:48] nikic@php.net WIP patch up at https://github.com/php/php-src/pull/3526. ------------------------------------------------------------------------ [2018-09-14 12:11:21] cmb@php.net The docs should be okay now, so changing to the actual bug. ------------------------------------------------------------------------ [2018-09-14 12:09:45] cmb@php.net Automatic comment from SVN on behalf of cmb Revision: http://svn.php.net/viewvc/?view=revision&amp;revision=345634 Log: Fix #76874: Documentation of memory leak in Xml Parser ------------------------------------------------------------------------ [2018-09-13 13:14:05] cmb@php.net Good catch, @ksours! This is not exactly the other bug, but it seems it has the same root cause. If an object references a resource, and this resource references that object, there is a cycle that could only be resolved by the cyclic GC, but since resources are not tracked (and that's unlikely to happen in the future), it won't. The proper solution would be to turn the parser resource into an object. ------------------------------------------------------------------------ [2018-09-12 20:42:51] ksours at internetbrands dot com Poked this a little farther and determined there is some more nuance than I originally understood. Here is the code to reproduce my case (can't seem to update the script field via the edit interface) <?php class c { private $xml; private $test; public function test() { $this->xml = xml_parser_create(); xml_set_character_data_handler($this->xml, array(&$this, 'handle_cdata')); xml_parser_free($this->xml); $this->test = str_repeat('xxxxx', 1000000); } public function test2() { $xml = xml_parser_create(); xml_set_character_data_handler($xml, array(&$this, 'handle_cdata')); xml_parser_free($xml); $this->test = str_repeat('xxxxx', 1000000); } public function test3() { $this->xml = xml_parser_create(); xml_set_character_data_handler($this->xml, array(&$this, 'handle_cdata')); xml_set_character_data_handler($this->xml, null); xml_parser_free($this->xml); $this->test = str_repeat('xxxxx', 1000000); } public function handle_cdata(&$parser, $data) { } } for($i = 1; $i < 100; $i++) { $object = new c(); $object->test(); unset($object); var_dump(memory_get_usage(true) / (1024*1024)); } ?> Note that test will show the memory leak, but test2 and test3 don't. I don't know if that's the same as bug #72793 or not. ------------------------------------------------------------------------ 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=76874 -- Edit this bug report at https://bugs.php.net/bug.php?id=76874&edit=1