RFR: 8367013: Add Atomic<T> to package/replace idiom of volatile var plus AtomicAccess:: operations [v4]

[David Holmes]

On Tue, 21 Oct 2025 14:54:22 GMT, Kim Barrett <kbarrett at openjdk.org> wrote:

>> src/hotspot/share/runtime/atomic.hpp line 84:
>> 
>>> 82: // Default construction of an atomic integer or atomic byte initializes the
>>> 83: // value to zero. Default construction of an atomic pointer initializes the
>>> 84: // value to null.
>> 
>> Suggestion:
>> 
>> // value to nullptr.
>> 
>> Optional, and total nit-pick. Reason: we are in C++ and not Java.
>
> We generally use "null" in comments, unless it's part of a code snippet.

Yes the convention is that we can talk generally about the concept of null-ness and of a value being null, and only use `nullptr` when referring to actual code.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27539#discussion_r2450390239