On Wed, 10 Apr 2024 12:49:11 GMT, Per Minborg <pminb...@openjdk.org> wrote:
> This PR proposes to add two overloads `MemorySegment::reinterpretate` to
> allow aligned reinterpretation.
src/java.base/share/classes/jdk/internal/foreign/SegmentFactories.java line 72:
> 70: sessionImpl.addCloseAction(action);
> 71: }
> 72: return new NativeMemorySegmentImpl(Utils.alignUp(min,
> byteAlignment), byteSize, false, sessionImpl);
This is not correct. The base address of the segment should not change after a
call to reinterpret. The alignment constraint should just be used for checking
that the base address is somewhat sane. Instead, I think `reinterpretInternal`
or the overloads that take a memory layout should do the check of the alignment
of `addres()` with the given alignment constraint.
test/jdk/java/foreign/TestSegments.java line 396:
> 394: AtomicInteger counter = new AtomicInteger();
> 395: try (Arena arena = Arena.ofConfined()){
> 396: var segment =
> MemorySegment.ofAddress(41).reinterpret(JAVA_INT);
i.e. this call (and the one below) should throw an exception.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/18717#discussion_r1559643107
PR Review Comment: https://git.openjdk.org/jdk/pull/18717#discussion_r1559649552
