The issue is *not* the order in which the Zend Engine is loading them
in, but the order it is unloading them in. Switching order for
loading was a fix that just happened to work. With the patch I
provided I can put them in any order and it works.
Looking at the Apache source it keeps a list of loaded DSOs and when
it loads one pushes it on to the head of the list. This way when it
iterates over the list to unload them it is in reverse order than it
loaded them. I have been told by a few co-workers that it is
industry standard to unload in reverse order that you loaded, but I
wanted at least one example so I looked at the Apache source.
Shouldn't the Zend Engine always unload extension in reverse order it
loaded them in?
Thanks!
Brian
BTW, I think the priority for loading in the ini should be an
option, but a completely different subject.
At 12:12 PM -0700 6/7/02, brad lafountain wrote:
> If this is your problem maybe a "offical" soultion to the problem should be
>thought. Like in your extension you can define a priority for loading and
>unloading your extension in the ini. Kinda like init.d.
>
> Has there been any discussion about this topic before.
>
> - brad
>
>--- Brian France <[EMAIL PROTECTED]> wrote:
>> Zend Engine unloading extension in the wrong order! (Re-post due to
>> no response)
>>
>> 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 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)
>> {
>>
>> --
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>>
>
>
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