[foreign-memaccess+abi] RFR: 8294986: Possible mismatched acquire/release in binding specializer

[Maurizio Cimadamore]

On Tue, 11 Oct 2022 14:47:31 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

> We acquire sessions of address parameters before a downcall, and release them afterwards. However, if acquire fails with an exception, we still call release in the finally block.
> 
> Fixing this is a simple case of switching 2 lines: when acquire fails, we don't store the session in a local, and so the cleanup in the finally block will not call release on it either.
> 
> For testing, I doesn't seem possible to make this bug result in an error with the current code. So, I've added an assert to the implementation that checks whether release was called too many times.

Looks good. Not super sure about the `assert`, which will only fire with assertion enabled. Historically I've been using `assert` keywords sparingly and using `throw new AssertError` more (especially in the javac code base), as that is guaranteed to fail. But that is subjective.

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Marked as reviewed by mcimadamore (Committer).

PR: https://git.openjdk.org/panama-foreign/pull/739