RFR: 8371956: Convert OopStorage to use Atomic<T>

[Stefan Karlsson]

On Sun, 16 Nov 2025 06:10:54 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

> Please review this change to OopStorage to use Atomic<T> rather than directly
> applying AtomicAccess to volatile members.
> 
> Testing: mach5 tier1-5

Looks like a good change.

There's one load_acquire below that isn't clear to me why it was used. I also noticed that we use `volatile` with `_owner_address`, is that because of the SafeFetch usage?

test/hotspot/gtest/gc/shared/test_oopStorage.cpp line 50:

> 48: 
> 49:   static ActiveArray& active_array(const OopStorage& storage) {
> 50:     return *storage._active_array.load_acquire();

Is there a reason why this was changed to `load_acquire` instead of `load_relaxed`?

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Marked as reviewed by stefank (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/28338#pullrequestreview-3472054244
PR Review Comment: https://git.openjdk.org/jdk/pull/28338#discussion_r2533544999