openImplicit

[Jorn Vernee]

Hi Michael,

I believe on Mac you might need to run with -XstartOnFirstThread [1] to 
get the right thread to run OpenGL applications on.

HTH,
Jorn

[1]: 
https://docs.oracle.com/en/java/javase/20/docs/specs/man/java.html#extra-options-for-macos

On 22/04/2023 02:32, Michael Hall wrote:
>
>> On Apr 21, 2023, at 7:24 PM, Maurizio Cimadamore <maurizio.cimadamore at oracle.com> wrote:
>>
>>
>> On 21/04/2023 22:16, Michael Hall wrote:
>>> I may of misunderstood implicit. I thought that gave you a garbage collection managed memory segment. So heap? I guess I was wrong.
>> With implicit/auto you can create a _native_ memory segment whose lifetime is managed automatically by the garbage collector. So, in a way, you're right that it works like a Java array, in the sense that when the segment becomes unreachable, its backing off-heap memory can be reclaimed (at some unspecified point). This is also the way in which the backing native memory of a direct byte buffer is managed.
>>
>> You can also obtain segments that are backed by on-heap memory, by wrapping a segment around a Java array. E.g. doing MemorySegment.ofArray(new int[200]). If you do that, the resulting segment will have a non-empty array.
>>
>> Since in your case you are working with off-heap memory (otherwise you wouldn't be able to exchange data with native functions), it is normal for the segment backing array to be null/empty, given that the memory segment is backed by a region of memory that resides off the Java heap.
>>
>> I hope this helps.
>>
>> Maurizio
>>
> Very completely explained. Possibly not completely understood yet. But hopefully will be as I continue.
>
> Thanks again.