On Fri, 31 Jul 2026 06:57:56 GMT, Per Minborg <[email protected]> wrote:
>> This PR proposes to improve the handling of the fields in >> `LazyCollections.Mutexes` so that it becomes more evident that there are no >> races. It is also proposed to add a defensive check of `mutexes` so that it >> is obvious to a reader that the `Unsafe` operation does not operate on >> `null`. Furthermore, it is proposed to remove the extra `AtomicInteger` >> object and use an `int` field directly. >> >> Please note that there is no (known) error in how the class `Mutexes` works. >> This PR only makes it more explicit and efficient. So, for example, we do >> not have to backport this PR. >> >> --------- >> - [x] I confirm that I make this contribution in accordance with the >> [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). > > Per Minborg has updated the pull request with a new target base due to a > merge or a rebase. The incremental webrev excludes the unrelated changes > brought in by the merge/rebase. The pull request contains six additional > commits since the last revision: > > - Clarify rational for memory semantics > - Merge branch 'master' into bug-race-in-mutexes > - Fix comment > - Improve comments > - Add comments and add explicit semantics > - Rework how Mutexes works src/java.base/share/classes/java/util/LazyCollections.java line 611: > 609: if (mutex != null) { > 610: return mutex; > 611: } What if `mutex == TOMB_STONE`? (Or if that can never occur, might make sense to document and/or assert that it never is) ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/32070#discussion_r3703100932
