On Fri, 3 Apr 2026 01:55:56 GMT, Chris Plummer <[email protected]> wrote:
> com/sun/jdi/EATests.java synchronizes on an Integer instance. Although this > currently works, it is discouraged. See the following doc on value based > classes: > > https://docs.oracle.com/en/java/javase/24/docs/api/java.base/java/lang/doc-files/ValueBased.html > > "Synchronization on instances of value-based classes is strongly discouraged, > because the programmer cannot guarantee exclusive ownership of the associated > monitor. > > Identity-related behavior of value-based classes may change in a future > release. For example, synchronization may fail." > > That second part is realized by Valhalla. The synchronization fails with: > > `java.lang.IdentityException: Cannot synchronize on an instance of value > class java.lang.Integer` > > Valhalla CR [JDK-8372831](https://bugs.openjdk.org/browse/JDK-8372831) covers > that failure, but I thought it best to address this in mainline first. > > Tested with all of CI tier1, tier2 svc, and tier5 svc. > > --------- > - [x] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). > > --------- > - [ ] I confirm that I make this contribution in accordance with the [OpenJDK > Interim AI Policy](https://openjdk.org/legal/ai). This pull request has now been integrated. Changeset: f2289d84 Author: Chris Plummer <[email protected]> URL: https://git.openjdk.org/jdk/commit/f2289d84d3b99686e90756921738d406f543337f Stats: 42 lines in 1 file changed: 1 ins; 41 del; 0 mod 8381609: com/sun/jdi/EATests.java should not synchronize on an Integer instance Reviewed-by: rrich, phubner, lmesnik, sspitsyn ------------- PR: https://git.openjdk.org/jdk/pull/30560
