(11) RFR (S) JDK-8196880: VS2017 Addition of Global Delete Operator with Size Parameter Conflicts with Arena's Chunk Provided One

[Thomas Stüfe]

On Wed, Feb 14, 2018 at 6:14 PM, Lois Foltan <lois.foltan at oracle.com> wrote:

> On 2/14/2018 9:26 AM, Thomas Stüfe wrote:
>
> Hi Lois,
>
> thanks for fixing this!
>
> Thanks for the review!
>
>
> Small nit, not part of your patch, but still:
>
> Chunks get allocated via CHeapObj::operator new() but deleted in
> Chunk::chop() with raw ::free(). Would it not be cleaner to call
> CHeapObj::operator delete() instead (it does a free() too, but that would
> be symmetrical? That would require that we actually implement
> Chunk::operator delete(), I guess.
>
> Sure, that seems reasonable and logical.  However, note it still doesn't
> alleviate the need to define a delete operator that takes a size
> parameter.  At the point where placement new is used, the compiler tries to
> find an appropriate matching operator delete and would error (C4291) with a
> failure to find one if not provided.
>
>
Makes sense.

Change is reviewed from my side.

Kind Regards, Thomas


> Thanks,
> Lois
>
>
> Best Regards, Thomas
>
>
> On Wed, Feb 14, 2018 at 2:48 PM, Lois Foltan <lois.foltan at oracle.com>
> wrote:
>
>> Please review this change in VS2017 to the delete operator due to C++14
>> standard conformance.  From https://msdn.microsoft.com/en-
>> us/library/mt723604.aspx
>>
>> The function|void operator delete(void *, size_t)|was a placement delete
>> operator corresponding to the placement new function "void * operator
>> new(size_t, size_t)" in C++11. With C++14 sized deallocation, this delete
>> function is now a/usual deallocation function/(global delete operator). The
>> standard requires that if the use of a placement new looks up a
>> corresponding delete function and finds a usual deallocation function, the
>> program is ill-formed.
>>
>> Thank you to Kim Barrett for proposing the fix below.
>>
>> open webrev at http://cr.openjdk.java.net/~lfoltan/bug_jdk8196880/webrev/
>> bug link https://bugs.openjdk.java.net/browse/JDK-8196880
>>
>> Testing complete (hs-tier1-3, jdk-tier1-3)
>>
>> Thanks,
>> Lois
>>
>>
>>
>
>