Bug #17643 Updated: Zend Engine unloading extension in the wrong order

ID: 17643 Updated by: list@firehawksystems.com Reported By: list@firehawksystems.com Status: Open Bug Type: Scripting Engine problem Operating System: FreeBSD 4.3, but any Unix PHP Version: 4.2.1 New Comment: After talking on the php-dev list it looks like zend_hash_graceful_reverse_destroy() would be a better fix as it doesn't require a new function, but does the same thing. Brian Previous Comments: ------------------------------------------------------------------------ [2002-06-07 12:13:02] list@firehawksystems.com I have been tracking down a core dump with my php extension when it is unloading some of its shared libraries. I have shared extension that is link against libexpat and will load fine if it is the only on in the php.ini. If I then load xml.so extension (also link against libexpat) then my extension it works fine, but if it is my extension then xml.so it crashes while xml.so is unloading libexapt. What I have found is the Zend Engine is unloading extension in the same order it loaded them. load: foo_bar.so load: xml.so unload: foo_bar.so unload: xml.so I believe this is wrong and think it should be in reverse order. load: foo_bar.so load: xml.so unload: xml.so unload: foo_bar.so There are two ways to fix this problem. One is to push the modules to the head of the hash, but looking at the zend_hash_add function I decided to go with the second. Second way is to destroy them in reverse order. I created a zend_hash_reverse_destroy and call that instead of zend_hash_destroy. There may be a better way to do this, but this is the quick fix for me. I have included a patch below, should I submit a bug report as well? Thanks, Brian diff -rc php-4.2.1/Zend/zend.c *** php-4.2.1/Zend/zend.c Tue Feb 26 10:59:25 2002 --- php-4.2.1/Zend/zend.c Thu Jun 6 11:32:57 2002 *************** *** 487,493 **** zend_destroy_rsrc_list(&EG(persistent_list) TSRMLS_CC); #endif zend_destroy_rsrc_list_dtors(); ! zend_hash_destroy(&module_registry); zend_hash_destroy(GLOBAL_FUNCTION_TABLE); free(GLOBAL_FUNCTION_TABLE); zend_hash_destroy(GLOBAL_CLASS_TABLE); --- 487,493 ---- zend_destroy_rsrc_list(&EG(persistent_list) TSRMLS_CC); #endif zend_destroy_rsrc_list_dtors(); ! zend_hash_reverse_destroy(&module_registry); zend_hash_destroy(GLOBAL_FUNCTION_TABLE); free(GLOBAL_FUNCTION_TABLE); zend_hash_destroy(GLOBAL_CLASS_TABLE); diff -rc php-4.2.1/Zend/zend_hash.c *** php-4.2.1/Zend/zend_hash.c Mon Apr 22 23:53:26 2002 --- php-4.2.1/Zend/zend_hash.c Thu Jun 6 11:32:57 2002 *************** *** 550,555 **** --- 550,579 ---- SET_INCONSISTENT(HT_DESTROYED); } + ZEND_API void zend_hash_reverse_destroy(HashTable *ht) + { + Bucket *p, *q; + + IS_CONSISTENT(ht); + + SET_INCONSISTENT(HT_IS_DESTROYING); + + p = ht->pListTail; + while (p != NULL) { + q = p; + p = p->pLast; + if (ht->pDestructor) { + ht->pDestructor(q->pData); + } + if (!q->pDataPtr && q->pData) { + pefree(q->pData, ht->persistent); + } + pefree(q, ht->persistent); + } + pefree(ht->arBuckets, ht->persistent); + + SET_INCONSISTENT(HT_DESTROYED); + } ZEND_API void zend_hash_clean(HashTable *ht) { ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=17643&edit=1