8374328: Convert simple AtomicAccess uses in gc/shared to use Atomic<T>

[kimbarrett]

Please review these fairly simple changes to code in gc/shared to use
Atomic<T> instead of directly using AtomicAccess.

This change doesn't eliminate all remaining direct uses of AtomicAccess in
that directory; there are still a few uses that seem less simple, and maybe
some that should stay with direct AtomicAccess.

The changes are grouped into a series of commits, as a potential aid to reviewers.

Testing: mach5 tier1-5

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8374328: Convert simple AtomicAccess uses in gc/shared to use Atomic<T> (Enhancement - P4)

Reviewers

• David Holmes (@dholmes-ora - Reviewer)
• Thomas Schatzl (@tschatzl - Reviewer) Review applies to ad121490

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/28987/head:pull/28987
$ git checkout pull/28987

Update a local copy of the PR:
$ git checkout pull/28987
$ git pull https://git.openjdk.org/jdk.git pull/28987/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 28987

View PR using the GUI difftool:
$ git pr show -t 28987

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/28987.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back kbarrett! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@kimbarrett This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8374328: Convert simple AtomicAccess uses in gc/shared to use Atomic<T>

Reviewed-by: dholmes, tschatzl

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 9 new commits pushed to the master branch:

• e6abf98: 8374434: Several JShell tests report JUnit discovery warnings
• 9513758: 8374662: Remove unused type check functions from javaClasses.hpp
• 70669d0: 8374712: AOTMappedHeapWriter::relocate_field_in_buffer should use CompressedOops::narrow_oop_cast
• ... and 6 more: https://git.openjdk.org/jdk/compare/da14813a5bdadaf0a1f81fa57ff6e1b103eaf113...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[openjdk]

@kimbarrett The following label will be automatically applied to this pull request:

• hotspot

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

[mlbridge]

Webrevs

• 02: Full - Incremental (c07dae40)
• 01: Full - Incremental (ad121490)
• 00: Full (0abdb185)

[dholmes-ora]

This all looks fine to me. Thanks.

[tschatzl]

All good.

[kimbarrett]

Fixed merge conflict in copyright header date in gcLocker.hpp. Needs re-review @tschatzl and @dholmes-ora

[kimbarrett]

Thanks for reviews @dholmes-ora and @tschatzl

[kimbarrett]

/integrate

[openjdk]

Going to push as commit c5159fc.
Since your change was applied there have been 14 commits pushed to the master branch:

• 904ba5f: 8374718: Generation of CompilerProperties can fail in subtle ways
• 067fd3c: 8374768: S390X builds are failing after JDK-8372754
• 08ff16f: 8374576: Disable MemoryEaterMT for VirtualThread
• ... and 11 more: https://git.openjdk.org/jdk/compare/da14813a5bdadaf0a1f81fa57ff6e1b103eaf113...master

Your commit was automatically rebased without conflicts.

[openjdk]

@kimbarrett Pushed as commit c5159fc.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.