#23548 [Fbk]: Memory leak

ID: 23548 Updated by: moriyoshi@php.net Reported By: neon at neon-line dot net Status: Feedback Bug Type: Scripting Engine problem Operating System: Debian Linux PHP Version: 4.3.2RC2 New Comment: It looks like your script uses objects to represent some tree-like structure and those objects have circular references. That is, <?php class foo { var $childs; var $parent; function foo() { $this->childs = array(); $this->parent = NULL; } function appendChild(&$child) { $this->childs[] = &$child; $child->setParent($this); } function setParent(&$parent) { $this->parent = &$parent; } } $a = &new foo(); $b = &new foo(); $a->appendChild($b); ?> This causes awful leaks, but it's inevitable due to the language design; PHP employs reference-count based garbage collection. Previous Comments: ------------------------------------------------------------------------ [2003-05-08 11:37:14] neon at neon-line dot net Feel free to mark this back to Feedback status. Leak hapends after data has been sent and script is about to exit. I'm unable to reproduct the problem with a short script. ------------------------------------------------------------------------ [2003-05-08 11:18:19] neon at neon-line dot net I have been unable to create a short reproducing script so far. Still working on it, but I have very litle information what might cause this memory leak. Still trying to figure that out. ------------------------------------------------------------------------ [2003-05-08 10:04:18] edink@php.net It is very difficult to determine anything without a short reproducing script. Could you try doing that? ------------------------------------------------------------------------ [2003-05-08 09:58:12] neon at neon-line dot net I'm still unable to create/locate code which causes this leak, but I'll give it as soon as I locate it. Because there is no use to paste tons of code. Bug was found while testing phpSysInfo script (propably in XPath.class). /root/php4-STABLE-200304251730/Zend/zend_execute.c(489) : Freeing 0x087D418C (12 bytes), script=/www/system/index.php Last leak repeated 129 times /root/php4-STABLE-200304251730/Zend/zend_execute.c(1214) : Freeing 0x087D414C (12 bytes), script=/www/system/index.php Last leak repeated 50 times /root/php4-STABLE-200304251730/Zend/zend_execute.c(478) : Freeing 0x087D410C (12 bytes), script=/www/system/index.php Last leak repeated 52 times /root/php4-STABLE-200304251730/Zend/zend_operators.c(1056) : Freeing 0x087D4004 (32 bytes), script=/www/system/index.php Last leak repeated 101 times /root/php4-STABLE-200304251730/Zend/zend_hash.c(406) : Freeing 0x087CE264 (35 bytes), script=/www/system/index.php Last leak repeated 174 times /root/php4-STABLE-200304251730/Zend/zend_execute.c(278) : Freeing 0x087CE224 (12 bytes), script=/www/system/index.php Last leak repeated 116 times /root/php4-STABLE-200304251730/Zend/zend_operators.c(1049) : Freeing 0x087CE084 (4 bytes), script=/www/system/index.php Last leak repeated 70 times /root/php4-STABLE-200304251730/Zend/zend_hash.c(178) : Freeing 0x087CDEEC (32 bytes), script=/www/system/index.php Last leak repeated 74 times /root/php4-STABLE-200304251730/Zend/zend_execute.c(764) : Freeing 0x087CDA84 (12 bytes), script=/www/system/index.php Last leak repeated 261 times /root/php4-STABLE-200304251730/Zend/zend_hash.c(440) : Freeing 0x087CDE24 (64 bytes), script=/www/system/index.php Last leak repeated 58 times /root/php4-STABLE-200304251730/Zend/zend_hash.c(262) : Freeing 0x087CDDC4 (41 bytes), script=/www/system/index.php Last leak repeated 532 times /root/php4-STABLE-200304251730/ext/xml/xml.c(262) : Freeing 0x087CD7EC (8 bytes), script=/www/system/index.php Last leak repeated 57 times /root/php4-STABLE-200304251730/ext/xml/xml.c(258) : Freeing 0x08690754 (12 bytes), script=/www/system/index.php Last leak repeated 57 times /root/php4-STABLE-200304251730/Zend/zend_API.c(678) : Freeing 0x0869113C (12 bytes), script=/www/system/index.php Last leak repeated 1 time /root/php4-STABLE-200304251730/ext/xml/xml.c(512) : Freeing 0x086910FC (11 bytes), script=/www/system/index.php Last leak repeated 1 time /root/php4-STABLE-200304251730/ext/xml/xml.c(648) : Freeing 0x0868F504 (44 bytes), script=/www/system/index.php /root/php4-STABLE-200304251730/Zend/zend_API.c(562) : Actual location (location was relayed) /root/php4-STABLE-200304251730/Zend/zend_execute_API.c(341) : Freeing 0x087B1ECC (44 bytes), script=/www/system/index.php /root/php4-STABLE-200304251730/Zend/zend_variables.c(122) : Actual location (location was relayed) Last leak repeated 3 times /root/php4-STABLE-200304251730/ext/xml/xml.c(647) : Freeing 0x0877A21C (12 bytes), script=/www/system/index.php Zend/zend_language_scanner.c(4675) : Freeing 0x086C1EEC (1 bytes), script=/www/system/index.php /root/php4-STABLE-200304251730/Zend/zend_compile.c(1866) : Freeing 0x086C1E4C (12 bytes), script=/www/system/index.php Last leak repeated 3 times Sorry that I can't give detailed description. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=23548&edit=1