RFR: 8325937: runtime/handshake/HandshakeDirectTest.java causes "monitor end should be strictly below the frame pointer" assertion failure on AArch64 [v2]

[Andrew Haley]

On Thu, 3 Oct 2024 17:33:49 GMT, Robbin Ehn <rehn at openjdk.org> wrote:

> The old implementation cleary had this as it specification (before we switched to pthread):
> 
> ```
> // See orderAccess.hpp.  We assume throughout the VM that mutex lock and
> // try_lock do fence-lock-acquire, and that unlock does a release-unlock,
> // *in that order*.  If their implementations change such that these
> // assumptions are violated, a whole lot of code will break.
> ```

Aha! I've never seen that.

> This code is written for that documented behavior. Hence I instead suggest to create a stricter mutex which follows the old semantics.

That seems rather brutal, but I follow your logic.

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

PR Comment: https://git.openjdk.org/jdk/pull/21295#issuecomment-2393238505