[foreign] RFR 8222765: Implement foreign memory access through VarHandle

[Maurizio Cimadamore]

Just pushed this, under the branch name 'foreign-memaccess'.

Maurizio

On 03/05/2019 17:46, Maurizio Cimadamore wrote:
> Here's a new revision based on some comments from Jorn:
>
> * revised VarHandle templating logic - now there's a single 
> VarHandleMemoryAddressBase declared in j.l.i package
>
> * added more carrier checks to VarHandles::makeMemoryAddressViewHandle 
> (and test)
>
> * made layout lookup logic uniform between values and group (before, 
> group lookup would not check if the group itself matched the condition)
>
> http://cr.openjdk.java.net/~mcimadamore/panama/8222765_v3/webrev/
>
> Maurizio
>
>
> On 19/04/2019 21:48, Maurizio Cimadamore wrote:
>> Fixed the template:
>>
>> http://cr.openjdk.java.net/~mcimadamore/panama/8222765_v2/
>>
>> I'd prefer to address the API issues in follow up issues, as we keep 
>> going through the API (also with Brian and others).
>>
>> Cheers
>> Maurizio
>>
>> On 19/04/2019 20:07, Jorn Vernee wrote:
>>> AFAIK it ensures that there is a unique name for the variables used 
>>> in the macro.
>>>
>>> e.g. if t = Byte then $1_Type expands to 
>>> VAR_HANDLE_BYTE_ARRAY_Byte_Type, as variable name. But, this 
>>> currently conflicts with the GenerateVarHandleByteArray macro for 
>>> some types.
>>>
>>> Jorn
>>>
>>> Maurizio Cimadamore schreef op 2019-04-19 19:55:
>>>> After a closer look, it seems like the first parameter to the macro is
>>>> not used. The macro GenerateVarHandleXYZ does, as its first thing:
>>>>
>>>> $1_Type := $2
>>>>
>>>> And then keeps using $1_Type after that.
>>>>
>>>> Maybe the $1 parameter is some remains of older code.
>>>>
>>>> Maurizio
>>>> On 19/04/2019 17:42, Maurizio Cimadamore wrote:
>>>>
>>>>> On 19/04/2019 16:46, Jorn Vernee wrote:
>>>>>
>>>>>> - In GensrcVarHandles.gmk you seem to have a mistake in the
>>>>>> generation command:
>>>>>>
>>>>>> 274 # List the types to generate source for, with capitalized
>>>>>> first letter
>>>>>> 275 VARHANDLES_MEMORY_ADDRESS_TYPES := Byte Short Char Int Long
>>>>>> Float Double
>>>>>> 276 $(foreach t, $(VARHANDLES_MEMORY_ADDRESS_TYPES), \
>>>>>> 277   $(eval $(call
>>>>>> GenerateVarHandleMemoryAddress,VAR_HANDLE_BYTE_ARRAY_$t,$t)))
>>>>>>
>>>>>> You still have to change the name VAR_HANDLE_BYTE_ARRAY_ to
>>>>>> something else (probably forgotten when copy pasting?)
>>>>> Good point, I wonder why it  still works??? I'll take another look.
>>>>> The right classes are definitively generated.