RFR: 8371923: Update LockFreeStack for Atomic<T> [v2]

[David Holmes]

On Tue, 18 Nov 2025 10:48:57 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

>> Please review this change to the `LockFreeStack` utility to allow clients to
>> use `Atomic<T>` as the type of the "next" member used in the linked-list
>> representation of the stack. It also continues to allow clients to use the old
>> (pre-`Atomic<T>`) form where the "next" member is volatile. This allows
>> clients to be updated incrementally after this change, rather than requiring
>> all clients to be updated in conjunction with the update of this class. Once
>> all clients have been updated, support for the old form can be removed.
>> 
>> The associated gtests have been updated to use `Atomic<T>`, with testing of
>> the old form is no longer being done. The non-updated uses provide some
>> testing, and that's all expected to go away soon. So parameterizing the gtests
>> for both forms seems like a bunch of work that will just be deleted soon, with
>> very little benefit.
>> 
>> Testing: mach5 tier1
>
> Kim Barrett 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 three additional commits since the last revision:
> 
>  - Merge branch 'master' into lock-free-stack-allows-new-atomic
>  - rename next_access to next_accessor
>  - LockFreeStack supports Atomic<T>

Looks good. Thanks

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Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/28329#pullrequestreview-3481585739