[foreign-memacces] RFR 8224993: Add Unsafe support for MemoryAddress

[Maurizio Cimadamore]

Fixed and pushed thanks!

Maurizio

On 29/05/2019 18:31, Jorn Vernee wrote:
> Hi,
>
> This looks good!
>
> But, there's 1 conversion from a jlong to a jint in libNativeAccess.c, 
> which causes a warning, which then causes an error when building (due 
> to -Werror). The conversion happens in Java_TestNative_getCapacity. 
> Note that GetDirectBufferCapacity returns a jlong.
>
> After changing the return type of Java_TestNative_getCapacity to 
> jlong/long as well I'm seeing all tests green.
>
> Cheers,
> Jorn
>
> Maurizio Cimadamore schreef op 2019-05-29 18:17:
>> Hi,
>> after adding byte buffer interop support, I think it's worth looking
>> at another avenue of migration - that is, translating a MemoryAddress
>> into a base/offset coordinate pair, used by the Unsafe class.
>>
>> http://cr.openjdk.java.net/~mcimadamore/panama/8224993/
>>
>> In addition to add the trivial Unsafe capabilities, this patch also
>> fixes some issues that were left unaddressed after the addition of
>> ByteBuffer support - more specifically, the wrapped 'scoped' buffers
>> do not have the 'address' , 'hb' and the 'capacity' fields set -
>> unfortunately, these fields are accessed in a raw fashion to implement
>> JNI functionalites such as GetDirectBufferAddress and
>> GetDirectBufferCapacity.
>>
>> I've also removed the bit-swapping from the
>> VarHandleMemoryAddressAsBytes class - after all, NativeOrder deals
>> with _byte_ swapping, so there's nothing meaningful we can do at the
>> byte level (and that's also consistent with what ByteBuffer does).
>>
>> Cheers
>> Maurizio