On Mon, 26 Feb 2024 13:24:11 GMT, Jorn Vernee <jver...@openjdk.org> wrote:
> This patch changes the alignment for `JAVA_LONG` and `JAVA_DOUBLE` to 8, > regardless of the underlying platform. This means that atomic access modes > work on memory segments wrapping `long[]` or `double[]`, as they already do > when using `MethodHandless::arrayAccessVarHandle`. > > After discussion, we came to the conclusion that it is reasonable for the JDK > to require the elements of a `long[]` and `double[]` to be 8 byte aligned. It > is ultimately up to the JDK to set these requirements, which are for the VM > to implement. > > I was seeing a stack overflow when running > test/jdk/java/foreign/stackwalk/TestReentrantUpcalls.java on x86, so I've > lowered the recursion to 50 (which is still more than enough I think). > > Testing: `jdk_foreign` on x64 Windows, x64 Windows + fallback linker, and x86 > Linux (uses fallback linker) This pull request has now been integrated. Changeset: 2372aba6 Author: Jorn Vernee <jver...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/2372aba6a21c569d4d724396e59b9fd1bec90682 Stats: 67 lines in 10 files changed: 18 ins; 23 del; 26 mod 8326172: Dubious claim on long[]/double[] alignment in MemorySegment javadoc Reviewed-by: mcimadamore ------------- PR: https://git.openjdk.org/jdk/pull/18007
