Hm, seems JSC_ZOMBIES do something similar (does it?), I give it a try.

Zoltan

> I've started writing up a page detailing how to avoid screwing up GC, it's
> far from complete but it has some info that may be useful to people:
> https://trac.webkit.org/wiki/How%20to%20not%20mess%20up%20GC
>
> In response to the other questions: It is still mark/sweep, Cells are no
> longer fixed size, it doesn't move anything, Weak<> and Strong<> are
> handles in the usual gc sense -> they're pointers to pointers (or in this
> case JSValues)
>
> --Oliver
>
>
> On May 18, 2011, at 10:54 AM, Zoltan Herczeg wrote:
>
>> Hi,
>>
>> I am currently debugging a nasty GC bug. (This one:
>> https://bugs.webkit.org/show_bug.cgi?id=60881) In short,
>> inspector/styles/metrics-box-sizing.html fails in the interpreter with
>> ASSERT_GC_OBJECT_LOOKS_VALID(cell) if all inspector/ tests are running
>> by
>> run-webkit-tests (32 bit, debug mode), but it passes if you test it
>> alone.
>>
>> Actually for tracking memory related issues the valgrind tool has an
>> excellent approach: never reuse the same address. This way we can keep
>> track of the freed chunks. Would it be possible to implement something
>> similar in the GC for JavaScriptCore (disabled by default with some
>> directives)? We would still run the GC as usual, but instead of reusing
>> the cells, we would always allocate a new chunk bz mmap. Naturally the
>> freed cells would contain some invalid pointers to cause crashes, and
>> perhaps a descriptor which describes where it was originally allocated.
>> Would it be feasible to add such feature to JavaScriptCore?
>>
>> Besides I saw a lot of improvements in GC. Is it still a mark and don't
>> sweep allocator? Is it still allocates fixed size cells? Does it move
>> cells? Does Weak<T> contains a GC'ed pointer?
>>
>> Regards,
>> Zoltan
>>
>>
>> _______________________________________________
>> squirrelfish-dev mailing list
>> [email protected]
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