[foreign-memaccess] RFR: Memory access implementation rewrite - post cleanup

[Jorn Vernee]

On Wed, 15 Apr 2020 13:46:16 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

> * Fix access modes not preserved in AbstractMemorySegmentImpl.ofBuffer
> * Add check to ensure that Foreign::withSize and Foreign::asMallocSegment are called with unchecked address

Besides testing whether read-only would be preserved for round trips, I think it would be nice to also test that lack
of CLOSE and ACQUIRE are preserved. How about:

    @Test
    public void testRoundTripAccess() {
        try(MemorySegment ms = MemorySegment.allocateNative(4)) {
            MemorySegment msNoAccess = ms.withAccessModes(MemorySegment.READ); // READ is required to make BB
            MemorySegment msRoundTrip = MemorySegment.ofByteBuffer(msNoAccess.asByteBuffer());
            assertEquals(msNoAccess.accessModes(), msRoundTrip.accessModes());
        }
    }
(tested locally)

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Otherwise looks good. Thanks for fixing!

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Marked as reviewed by jvernee (Committer).

PR: https://git.openjdk.java.net/panama-foreign/pull/111