Bug #14037 Updated: Memory leak in xmldocfile function

ID: 14037 Updated by: mfischer Reported By: mikep@oeone.com Old Status: Open Status: Assigned Bug Type: DOM XML related Operating System: Linux PHP Version: 4.0.6 Old Assigned To: Assigned To: mfischer New Comment: It probably segfaults becaue you don't delete the resource from the list and so it gets double freed which results in a crash (didn't looked thorougly though). The memory all gets freed upon scrip terrmination but I see the advantage of freeing the resources when no longer required. Assigned to me. Previous Comments: ------------------------------------------------------------------------ [2001-11-29 13:39:36] mikep@oeone.com I need a way to attach a file to this bug... Here is the diff: diff -ur php-4.0.6/ext/domxml/php_domxml.c php-4.0.6-haxx0red/ext/domxml/php_domxml.c --- php-4.0.6/ext/domxml/php_domxml.c Thu May 24 08:41:46 2001 +++ php-4.0.6-haxx0red/ext/domxml/php_domxml.c Tue Nov 13 17:26:03 2001 @@ -71,6 +71,7 @@ PHP_FE(domxml_set_attribute, NULL) PHP_FALIAS(domxml_setattr, domxml_set_attribute, NULL) PHP_FE(domxml_children, NULL) + PHP_FE(xmldocfree, NULL) //oeone PHP_FE(domxml_new_child, NULL) PHP_FE(domxml_node, NULL) PHP_FE(domxml_unlink_node, NULL) @@ -205,7 +206,7 @@ domxmltestnode_class_startup(); #endif - le_domxmldocp = zend_register_list_destructors_ex(php_free_xml_doc, NULL, "domxml document", module_number); + le_domxmldocp = zend_register_list_destructors_ex(php_free_xml_doc, php_free_xml_doc, "domxml document", module_number);//oeone /* Freeing the document contains freeing the complete tree. Therefore nodes, attributes etc. may not be freed seperately. */ @@ -1161,6 +1162,38 @@ zend_list_addref(ret); } /* }}} */ + +//oeone +PHP_FUNCTION(xmldocfree) +{ + zval *id, **tmp; + xmlDoc *docp; + xmlNode *node; + int ret; + + /* php_error( E_WARNING, "Oeone Destructor\n" ); */ + if (ZEND_NUM_ARGS() == 0) { + id = getThis(); + if (id) { + if (zend_hash_find(id->value.obj.properties, "doc", sizeof("doc"), (void **)&tmp) == FAILURE) { + php_error(E_WARNING, "unable to find my handle property"); + RETURN_FALSE; + } + ZEND_FETCH_RESOURCE(docp,xmlDocPtr,tmp,-1, "DomDocument", le_domxmldocp) + } else { + RETURN_FALSE; + } + } else if ((ZEND_NUM_ARGS() != 1) || getParameters(ht, 1, &id) == FAILURE) { + WRONG_PARAM_COUNT; + } else { + if (zend_hash_find(id->value.obj.properties, "doc", sizeof("doc"), (void **)&tmp) == FAILURE) { + php_error(E_WARNING, "unable to find my handle property"); + RETURN_FALSE; + } + ZEND_FETCH_RESOURCE(docp,xmlDocPtr,tmp,-1, "DomDocument", le_domxmldocp) + } + xmlFreeDoc(docp); +} /* {{{ proto object domxml_new_child([int node_handle,] string name, string content) Adds child node to parent node */ diff -ur php-4.0.6/ext/domxml/php_domxml.h php-4.0.6-haxx0red/ext/domxml/php_domxml.h --- php-4.0.6/ext/domxml/php_domxml.h Thu May 24 08:33:43 2001 +++ php-4.0.6-haxx0red/ext/domxml/php_domxml.h Tue Nov 13 17:26:03 2001 @@ -46,6 +46,7 @@ PHP_FUNCTION(domxml_add_root); PHP_FUNCTION(domxml_intdtd); PHP_FUNCTION(domxml_dumpmem); +PHP_FUNCTION(xmldocfree); //oeone /* Class Node methods */ PHP_FUNCTION(domxml_attributes); ------------------------------------------------------------------------ [2001-11-29 11:29:57] mikep@oeone.com Here's the explanation from mostafah@oeone.com (our resident C expert): In the ext/domxml/php_domxml.c there is a destructor function named php_free_xml_doc(). In the loop code that mikep@oeone.com has posted this destructor function gets invoked after the end of the loop which for some reason won't free up memory. We thought maybe the xmldoc memory should be released within the loop that is after getting an xmldoc object into $doc and before overwriting it through the next iteration of the loop. So we added our own xmldocfree( $doc ) function and put it in the loop. We had no memory leak anymore but then we encountered segfaults in the apache log file which of course was because of the native destructor being invoked on an already released object. So maybe even our xmldocfree wasn't working properly and the segfault was somehow cleaning up everything behind. But anyway we are happy now because the memory leak is gone and the segfault does not effect our functionality. ------------------------------------------------------------------------ [2001-11-29 09:48:25] mfischer@php.net By patching what? ext/domxml? FYI, apache doesn't release memory it once grabs. Thats how it works. Feedback. ------------------------------------------------------------------------ [2001-11-29 09:42:22] mikep@oeone.com As stated, the memory used by Apache sky rockets... On my machine, it goes up to about 90% or so. We're working on a patch to this bug, we've got the memory leak fixed by closing the file using a function we wrote, but unfortunately that ended up causing a segfault in Apache. When we fix that problem, we'll post the fix here. ------------------------------------------------------------------------ [2001-11-29 09:38:04] mfischer@php.net What do you define as 'memory leak' ? Error output in apaches log? Feedback. ------------------------------------------------------------------------ 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 http://bugs.php.net/?id=14037 Edit this bug report at http://bugs.php.net/?id=14037&edit=1