[foreign-memaccess+abi] RFR: 8263018: Improve API for lifecycle of native resources [v10]

[Paul Sandoz]

On Mon, 15 Mar 2021 17:34:10 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

> One option which I still find kind of appealing, is to add _instance_ methods to connect the various APIs. E.g. instead:
> 
> SegmentAllocator.of(scope) -> scope.toAllocator();
> SegmentAllocator.of(segment) -> segment.toSegment();
>

I think that works very well for `SegmentAllocator.of(segment)`, and implementation it could be quite efficient (same concrete class if need be).

Less sure about `SegmentAllocator.of(scope)` -> `ResourceScope.toAllocator()`, FWIW I noticed this is a subset of `malloc`:

ResourceScope scope = ...
SegmentAllocator fixedScopeAllocator = SegmentAllocator.malloc(() -> scope);

There might also be some interconnections with `ScopedSegmentAllocator`? Seems like we either want to compose through inheritance or have some bi-direction between the two abstractions.

-------------

PR: https://git.openjdk.java.net/panama-foreign/pull/466