It would ensure that the V8 has the correct Free method for it. If you keep a reference to memory after you explicitly give up ownership of its lifetime and it later gets freed, that is not the library's fault.
On Thursday, September 18, 2014 12:34:39 PM UTC-8, Dmitry Lomov wrote: > > > > On Thu, Sep 18, 2014 at 9:20 PM, Flying Jester <[email protected] > <javascript:>> wrote: > >> 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. >> > > How this restriction solves anything? > > >> >> 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]> >>> 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 >>> >>> >>> -- >> -- >> v8-users mailing list >> [email protected] <javascript:> >> http://groups.google.com/group/v8-users >> --- >> You received this message because you are subscribed to the Google Groups >> "v8-users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected] <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- -- v8-users mailing list [email protected] http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
