Re: How to create Persistent zval?
By the way, Is this the reason of date ext always check the global
HashTable and re-initialize the tzdata in every request?
Lin Yo-An <[email protected]> 於 2014年1月19日星期日寫道：
>
>
> Daniel Lowrey <[email protected] <javascript:_e({}, 'cvml',
> '[email protected]');>> 於 2014年1月19日星期日寫道：
>
>> >> Hello,
>> >>
>> >> I am trying to store a zval object into the persistent list in zend VM.
>> >> (Using EG(persistent_list) and zend_rscd_list_entry)
>> >>
>> >> Which works fine if I store/fetch the zval in the same request context.
>> >>
>> >> But it seems that zend engine cleans up the zval object after the
>> request,
>> >> when the next request comes, the fetched list entry points to a freed
>> zval
>> >> address and it makes php segmentationfault. I guess zval is allocated
>> by
>> >> emalloc, so I cant keep it cross requests?
>>
>> > For persistent alloc, you should use pemalloc() , which is just a
>> > wrapper leading to libc's malloc.
>> > If you use emalloc() , the Zend Memory Manager will free the storage
>> > at the end of the request, thus leading to use-after-free crash if you
>> > reuse your pointer on a next request.
>>
>> --- Disclaimer ---
>> I'm passing this along; Joe is having technical difficulties and asked for
>> help sending this to the list. I provide no warranties or refunds ;)
>> ---
>>
>> All zvals passed into the engine must be allocated by the mm, you cannot
>> pemalloc anything and pass it into the engine safely.
>>
>> You don't want to store a persistent zval, you want to store a persistent
>> resource entry, which should be allocated with pemalloc(size, 1)
>>
>> The reason for this is when cleaning up, the engine has no means by which
>> to tell if a zval has been pemalloc or emalloc'd, zval_ptr_dtor works the
>> same for everything.
>
>
>
> Thank you so much! That is what i was guessing.. - ref cnt and pemalloc
> does not work for persistent zval.
>
> And zend engine cleans up zvals at the end of request no matter the ref
> cnt is?
>
> so zval is not persistent, then is HashTable persistent?
>
> It's because I need to store a zval object which has several properties.
> Is there a way to do make the object persistent? Or do i need to serialize
> it just like apc?
>
>
>
>> Cheers
>> Joe
>>
>
>
> --
> Best Regards,
>
> Yo-An Lin
>
>
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