8295124: Atomic::add to pointer type may return wrong value

[shipilev]

Clean backport to improve Atomics support. Important to get it right to avoid future backporting accidents.

Additional testing:

• New testcases fail without the fix, pass with it
• Checked there are no current uses of Atomic::add with pointer types of size > 1
• Linux x86_64 server fastdebug, tier1
• Linux AArch64 server fastdebug, tier1

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8295124 needs maintainer approval

Issue

• JDK-8295124: Atomic::add to pointer type may return wrong value (Bug - P4 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk17u-dev.git pull/2043/head:pull/2043
$ git checkout pull/2043

Update a local copy of the PR:
$ git checkout pull/2043
$ git pull https://git.openjdk.org/jdk17u-dev.git pull/2043/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 2043

View PR using the GUI difftool:
$ git pr show -t 2043

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk17u-dev/pull/2043.diff

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[bridgekeeper]

👋 Welcome back shade! 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]

This backport pull request has now been updated with issue from the original commit.

[shipilev]

/approval request Clean backport to improve Atomics support. Important to get it right to avoid future backporting accidents. Applies cleanly. Testing passes.

[openjdk]

⚠️ @shipilev This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[openjdk]

@shipilev
8295124: The approval request has been created successfully.

[mlbridge]

Webrevs

• 00: Full (20f97015)

[openjdk]

@shipilev 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:

8295124: Atomic::add to pointer type may return wrong value

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 4 new commits pushed to the master branch:

• fb950fa: 8316415: Parallelize sun/security/rsa/SignedObjectChain.java subtests
• 3a2bf8e: 8225377: type annotations are not visible to javac plugins across compilation boundaries
• 9596656: 8271118: C2: StressGCM should have higher priority than frequency-based policy
• f8e54a9: 8316929: Shenandoah: Shenandoah degenerated GC and full GC need to cleanup old OopMapCache entries

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

[shipilev]

/integrate

[openjdk]

Going to push as commit 519fd89.
Since your change was applied there have been 5 commits pushed to the master branch:

• 5bc2302: 8271616: oddPart in MutableBigInteger::mutableModInverse contains info on final result
• fb950fa: 8316415: Parallelize sun/security/rsa/SignedObjectChain.java subtests
• 3a2bf8e: 8225377: type annotations are not visible to javac plugins across compilation boundaries
• 9596656: 8271118: C2: StressGCM should have higher priority than frequency-based policy
• f8e54a9: 8316929: Shenandoah: Shenandoah degenerated GC and full GC need to cleanup old OopMapCache entries

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 519fd89.

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