8366035: Simplify CPUTimeCounters::publish_gc_total_cpu_time

[hgqxjj]

This change refactors CPUTimeCounters::publish_gc_total_cpu_time() to use Atomic::xchg instead of a CAS (cmpxchg) loop.
Please review it. Thanks

---

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-8366035: Simplify CPUTimeCounters::publish_gc_total_cpu_time (Enhancement - P4)

Reviewers

• Albert Mingkun Yang (@albertnetymk - Reviewer)
• Kim Barrett (@kimbarrett - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/26921/head:pull/26921
$ git checkout pull/26921

Update a local copy of the PR:
$ git checkout pull/26921
$ git pull https://git.openjdk.org/jdk.git pull/26921/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 26921

View PR using the GUI difftool:
$ git pr show -t 26921

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/26921.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back ghan! 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]

@hgqxjj 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:

8366035: Simplify CPUTimeCounters::publish_gc_total_cpu_time

Reviewed-by: ayang, kbarrett

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 17 new commits pushed to the master branch:

• 68abf76: 8366105: Update link to the external RuleBasedBreakIterator documentation
• 5013d69: 8365633: Incorrect info is reported on hybrid CPU
• e38c6f9: 8365656: [ubsan] G1CSetCandidateGroup::liveness() reports division by 0
• ... and 14 more: https://git.openjdk.org/jdk/compare/57434c73eac9bd6557b09d4a057e3a2a18f382b4...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.

As you do not have Committer status in this project an existing Committer must agree to sponsor your change. Possible candidates are the reviewers of this PR (@albertnetymk, @kimbarrett) but any other Committer may sponsor as well.

➡️ To flag this PR as ready for integration with the above commit message, type /integrate in a new comment. (Afterwards, your sponsor types /sponsor in a new comment to perform the integration).

[openjdk]

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

• hotspot-runtime

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

• 01: Full - Incremental (6dd9ff83)
• 00: Full (0b66b63c)

[albertnetymk]

/cc hotspot-gc

[openjdk]

@albertnetymk
The hotspot-gc label was successfully added.

[kimbarrett]

Looks good.

[hgqxjj]

/integrate

[openjdk]

@hgqxjj
Your change (at version 6dd9ff8) is now ready to be sponsored by a Committer.

[hgqxjj]

@albertnetymk @kimbarrett Thanks for your reviews! I’ve integrated this PR. Could you please sponsor it?

[albertnetymk]

/sponsor

[openjdk]

Going to push as commit 2ae3ea2.
Since your change was applied there have been 17 commits pushed to the master branch:

• 68abf76: 8366105: Update link to the external RuleBasedBreakIterator documentation
• 5013d69: 8365633: Incorrect info is reported on hybrid CPU
• e38c6f9: 8365656: [ubsan] G1CSetCandidateGroup::liveness() reports division by 0
• ... and 14 more: https://git.openjdk.org/jdk/compare/57434c73eac9bd6557b09d4a057e3a2a18f382b4...master

Your commit was automatically rebased without conflicts.

[openjdk]

@albertnetymk @hgqxjj Pushed as commit 2ae3ea2.

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