8306321: Add an accessor for the top of a PLAB

[earthling-amzn]

The generational mode for Shenandoah needs to know the top of a PLAB when it is retired.

---

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-8306321: Add an accessor for the top of a PLAB

Reviewers

• Aleksey Shipilev (@shipilev - Reviewer)
• Y. Srinivas Ramakrishna (@ysramakrishna - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/13516/head:pull/13516
$ git checkout pull/13516

Update a local copy of the PR:
$ git checkout pull/13516
$ git pull https://git.openjdk.org/jdk.git pull/13516/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 13516

View PR using the GUI difftool:
$ git pr show -t 13516

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/13516.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back wkemper! 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]

@earthling-amzn The following label will be automatically applied to this pull request:

• hotspot-gc

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[mlbridge]

Webrevs

• 00: Full (86c19b70)

[shipilev]

This looks fine to me.

[openjdk]

@earthling-amzn 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:

8306321: Add an accessor for the top of a PLAB

Reviewed-by: shade, ysr

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 129 new commits pushed to the master branch:

• fdb4baf: 8306134: Open source some AWT tests relating to Button and a few other classes
• 4ad3ac6: 8306135: Clean up and open source some AWT tests
• 85de01e: 8306323: Update license files in CLDR v43
• 48fd4f2: 8303431: [JVMCI] libgraal annotation API
• c57af31: 8306038: SystemModulesPlugin generates code that doesn't pop when return value not used
• a31a11f: 8306006: strace001.java fails due to unknown methods on stack
• ddb8646: 8306123: Move InstanceKlass writeable flags
• 1a41e12: 8306310: Move is_shared Klass flag
• c738c8e: 8306278: jvmtiAgentList.cpp:253 assert(offset >= 0) failed: invariant occurs on AIX after JDK-8257967
• 9fb53ad: 8305716: Enhancements for printing age tables
• ... and 119 more: https://git.openjdk.org/jdk/compare/a8871f5d26e5cb42c031c7b736ec30b1b147a2bc...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 (@shipilev, @ysramakrishna) 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).

[earthling-amzn]

/integrate

[openjdk]

@earthling-amzn
Your change (at version 86c19b7) is now ready to be sponsored by a Committer.

[ysramakrishna]

/sponsor

[openjdk]

Going to push as commit ed34e7f.
Since your change was applied there have been 129 commits pushed to the master branch:

• fdb4baf: 8306134: Open source some AWT tests relating to Button and a few other classes
• 4ad3ac6: 8306135: Clean up and open source some AWT tests
• 85de01e: 8306323: Update license files in CLDR v43
• 48fd4f2: 8303431: [JVMCI] libgraal annotation API
• c57af31: 8306038: SystemModulesPlugin generates code that doesn't pop when return value not used
• a31a11f: 8306006: strace001.java fails due to unknown methods on stack
• ddb8646: 8306123: Move InstanceKlass writeable flags
• 1a41e12: 8306310: Move is_shared Klass flag
• c738c8e: 8306278: jvmtiAgentList.cpp:253 assert(offset >= 0) failed: invariant occurs on AIX after JDK-8257967
• 9fb53ad: 8305716: Enhancements for printing age tables
• ... and 119 more: https://git.openjdk.org/jdk/compare/a8871f5d26e5cb42c031c7b736ec30b1b147a2bc...master

Your commit was automatically rebased without conflicts.

[openjdk]

@ysramakrishna @earthling-amzn Pushed as commit ed34e7f.

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