RFR: 8367014: Rename class Atomic to AtomicAccess [v2]

[Kim Barrett]

On Wed, 10 Sep 2025 07:34:09 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

>> Please review this change that renames the all-static class `Atomic` to
>> `AtomicAccess`. The reason for this name change is to allow the introduction
>> of the new type `Atomic<T>` ([JDK-8367013](https://bugs.openjdk.org/browse/JDK-8367013)).
>> 
>> The PR has several commits, according to the specific category of change being
>> made. It may be easier to review the PR by studying these individual commits.
>> 
>> Although the file "atomic.hpp" is being renamed to "atomicAccess.hpp", I chose
>> to not rename the various "atomic_<cpu>.*" and "atomic_<os>_<cpu>.*" files.
>> 
>> There are a number of comments containing the word "Atomic" that I didn't
>> change. They are generically about atomic operations, and will just as well
>> serve as referring to the future `Atomic<T>`.
>> 
>> Testing: mach5 tier1, GHA sanity tests.
>> This is one of those changes where successful builds indicate the change is good.
>
> Kim Barrett has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 12 commits:
> 
>  - rename recently added Atomic:: => AtomicAccess::
>  - Merge branch 'master' into atomic-access
>  - fix prefiously missed arg misalignments
>  - rename test_atomic.cpp
>  - update copyrights
>  - misc cleanups
>  - fix indentation from rename
>  - rename Atomic => AtomicAccess in gtests
>  - rename Atomic => AtomicAccess
>  - change includes of atomic.hpp in gtests
>  - ... and 2 more: https://git.openjdk.org/jdk/compare/af9b9050...11007c45

Needs re-review because of updates to deal with merge conflicts and to update newly merged code that needed
the renamings applied. @stefank @theRealAph @dholmes-ora

Hm, now says there is a new merge conflict. Guess you folks should hold off on re-review.

src/hotspot/cpu/aarch64/gc/shared/barrierSetNMethod_aarch64.cpp line 118:

> 116:   }
> 117: 
> 118:   void set_value(int value, int bit_mask) {

This and similar changes for arm and riscv came from a merged changeset.
I took that new version and updated it for `Atomic::` => `AtomicAccess::` renaming.

src/hotspot/share/jfr/periodic/sampling/jfrCPUTimeThreadSampler.cpp line 394:

> 392:       last_recompute_check = os::javaTimeNanos();
> 393:     }
> 394:     DEBUG_ONLY(if (AtomicAccess::load_acquire(&_out_of_stack_walking_enabled)) {)

Another case of taking a merge update and then adjusting for `Atomic::` => `AtomicAccess::`.

src/hotspot/share/runtime/basicLock.inline.hpp line 32:

> 30: #include "runtime/objectMonitor.inline.hpp"
> 31: 
> 32: inline markWord BasicLock::displaced_header() const {

These functions were removed by a merge update.

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PR Comment: https://git.openjdk.org/jdk/pull/27135#issuecomment-3277397927
PR Comment: https://git.openjdk.org/jdk/pull/27135#issuecomment-3277401578
PR Review Comment: https://git.openjdk.org/jdk/pull/27135#discussion_r2338471419
PR Review Comment: https://git.openjdk.org/jdk/pull/27135#discussion_r2338472405
PR Review Comment: https://git.openjdk.org/jdk/pull/27135#discussion_r2338473094