Valhalla EG minutes 6/21/17

[Paul Sandoz]

I strongly suspect we can specify a safe version of Unsafe.defineAnonymousClass (minus constant pool patching) independent of nest mates. I believe that is desirable on it’s own as part of the replace unsafe functionality and if that can help MVT then even better!

Paul.

> On 5 Jul 2017, at 10:48, Karen Kinnear <karen.kinnear at oracle.com> wrote:
> 
> Agree with John’s clarification - yes we are planning longterm for nest mate access.
> And your proposal of using a safe replacement for Unsafe.defineAnonymousClass with
> appropriate access to add into the nest makes sense.
> 
> At this time we are building an Early Access that needs to go out sooner than nest mates.
> We should re-evaluate adding a nest mate dependency when we get closer to deadlines and
> see if that works for our partners and our own timing.
> 
> thanks,
> Karen
> 
>> On Jul 5, 2017, at 12:28 PM, Paul Sandoz <paul.sandoz at oracle.com> wrote:
>> 
>> 
>>> On 5 Jul 2017, at 07:26, Karen Kinnear <karen.kinnear at oracle.com> wrote:
>>> 
>>> Paul,
>>> 
>>> What we were discussing was the ability to use the byte code itself - not the ValueType.findWither API.
>>> John’s longer term plan is that ultimately the byte code can only be executed in the value class itself, and
>>> since the derived value class has no methods, we need a temporary approach.
>>> 
>>> Did I misunderstand what you were saying?
>>> 
>> 
>> No, i was missing aspect that you were referring to byte code generation.
>> 
>> What if we added a safe replacement for:
>> 
>> Unsafe.defineAnonymousClass
>> https://bugs.openjdk.java.net/browse/JDK-8171335
>> 
>> (Which we anyway have to do.)
>> 
>> ?
> 
>> 
>> Then the VCC or DVT could be used as the host class. However, i dunno if that would be sufficient to cover the use-cases of byte code generation.
> 
>> 
>> Paul.
>> 
>>> thanks,
>>> Karen
>>> 
>>>> On Jun 26, 2017, at 2:52 PM, Paul Sandoz <paul.sandoz at oracle.com> wrote:
>>>> 
>>>> 
>>>>> On 23 Jun 2017, at 13:33, Karen Kinnear <karen.kinnear at oracle.com> wrote:
>>>> 
>>>>> VWithfield - propose for MVT - allow package private access - since there are no methods on the derived value class
>>>>> and the value capable class can’t have any methods with vbytecodes since generated by javac
>>>>> - plan to make private when we add factory methods to value classes with a compiler (and we have nest support)
>>>>> 
>>>> 
>>>> I am unsure if it’s necessary for MVT purposes to dial back the accessibility then dial it up again later on.
>>>> 
>>>> ValueType.findWither can be used in conjunction with MethodHandle.privateLookupIn. It’s a little odd but works. What am i missing?
>>>> 
>>>> Paul.
>>>> 
>>>> 
>>>> 
>>>> 
>>> 
>> 
>