I don't believe you should be able to pass any old pointer into it. I'm 
saying it would vastly simplify things to be able to re-internalize a 
previously externalized pointer.

On Thursday, September 18, 2014 11:00:10 AM UTC-8, Dmitry Lomov wrote:
>
>
>
> On Fri, Sep 12, 2014 at 11:38 PM, Flying Jester <[email protected] 
> <javascript:>> wrote:
>
>>
>>
>> Since V8 does not know how the memory backing an ArrayBuffer has been 
>>> allocated in this case, there is now good way for V8 to free it. 
>>>
>>
>> This doesn't make sense.
>>
>> A part of v8::ArrayBuffer::Allocator is a Free method. When you pass an 
>> allocator to v8::V8::SetArrayBufferAllocator, you are giving V8 all the 
>> tools to both allocate and deallocate memory for an ArrayBuffer.
>>
>
> You can create an ArrayBuffer over external memory 
> (v8::ArrayBuffer::New(v8::Isolate*, void*, size_t)). V8 has no idea how 
> this data has been allocated.
>
>>
>> I see absolutely no reason why you can't make the ArrayBuffer take 
>> ownership of the memory again when you are done with it. It took ownership 
>> when it was created. If it can't take ownership again, this sounds to me 
>> like a limitation of it's implementation, not an actual virtue of its 
>> design.
>>
>
> I can imagine the API where embedder says to V8: "hey ArrayBuffer I 
> absolutely know what I am doing take ownership of this void*". The problem 
> with that is that people usually don't, they keep the reference to the 
> void* somewhere and later when an ArrayBuffer is garbage-collected it is 
> use-after-free and misery. I do not have a good solution for that yet.
>
> Dmitry
>
>
>

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