8320707: Virtual thread test updates

[shipilev]

Test-only backport that simplifies Loom maintenance. The original commit applies cleanly, but it does not work out of the box, because VThreadPinner uses FFM, which is a preview feature in JDK 21, made final in JDK 22. My attempts to soft-touch FFM into working in JDK 21 with these tests failed: x86_32's fallback linker does not work properly in JDK 21, so tests cannot complete there.

Therefore, I made a side-ways move here: rewrote VThreadPinner to use synchronized, which still pins the thread in JDK 21, and would likely continue doing so. It is unlikely we would backport the runtime changes required to avoid pinning on synchronized blocks. This is what the old tests did anyway.

This would also make subsequent backports clean.

Additional testing:

• MacOS AArch64 server fastdebug, jdk_loom hotspot_loom

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• JDK-8320707 needs maintainer approval
• Commit message must refer to an issue

Issue

• JDK-8320707: Virtual thread test updates (Enhancement - P4 - Approved)

Reviewers

• Volker Simonis (@simonis - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/328/head:pull/328
$ git checkout pull/328

Update a local copy of the PR:
$ git checkout pull/328
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/328/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 328

View PR using the GUI difftool:
$ git pr show -t 328

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u-dev/pull/328.diff

Webrev

Link to Webrev Comment

[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.

[mlbridge]

Webrevs

• 01: Full - Incremental (17752923)
• 00: Full (fc6dd1fa)

[shipilev]

GHA x86_32 tests are failing, I think we need #330 first.

[shipilev]

Grr, the x86_32 thing does not work. Getting back to draft until I can figure it out.

[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:

8320707: Virtual thread test updates

Reviewed-by: simonis

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 29 new commits pushed to the master branch:

• 031acf1: 8327096: (fc) java/nio/channels/FileChannel/Size.java fails on partition incapable of creating large files
• 324cef1: 8327971: Multiple ASAN errors reported for metaspace
• ac402fb: 8293850: need a largest_committed metric for each category of NMT's output
• febbf35: 8316242: Opensource SwingGraphics manual test
• 1861655: 8316154: Opensource JTextArea manual tests
• a36d3de: 8328957: Update PKCS11Test.java to not use hardcoded path
• bb046b7: 8320525: G1: G1UpdateRemSetTrackingBeforeRebuild::distribute_marked_bytes accesses partially unloaded klass
• ffdde9c: 8320331: G1 Full GC Heap verification relies on metadata not reset before verification
• d11a065: 8187759: Background not refreshed when painting over a transparent JFrame
• 5880551: 8318854: [macos14] Running any AWT app prints Secure coding warning
• ... and 19 more: https://git.openjdk.org/jdk21u-dev/compare/7743b6ca05b8486eeb38cbbe74569401ce62fe2a...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.

[shipilev]

@jerboaa, @GoeLin -- good for 21u, or?

[jerboaa]

Seems fine to me.

[jerboaa]

Being a good citizen would need a 22u backport first.

[shipilev]

Seems fine to me.

Thanks!

Being a good citizen would need a 22u backport first.

Not sure we want to do tests maintenance in a soon-to-be-dead release, but here it is: openjdk/jdk22u#160

[shipilev]

/approval request Test-only backport that simplifies Loom maintenance. The original commit applies cleanly, but does not work, because tests use FFM that are not stable in JDK 21, rewritten back to synchronized. See 21u PR for more details. Loom tests pass. Low risk, test-only change.

[openjdk]

@shipilev
8320707: The approval request has been created successfully.

[simonis]

Looks good!

Nice idea to use synchronized (runner).

[shipilev]

/integrate

[openjdk]

Going to push as commit 41237fc.
Since your change was applied there have been 30 commits pushed to the master branch:

• 955fcc1: 8310355: Move the stub test from initialize_final_stubs() to test/hotspot/gtest
• 031acf1: 8327096: (fc) java/nio/channels/FileChannel/Size.java fails on partition incapable of creating large files
• 324cef1: 8327971: Multiple ASAN errors reported for metaspace
• ac402fb: 8293850: need a largest_committed metric for each category of NMT's output
• febbf35: 8316242: Opensource SwingGraphics manual test
• 1861655: 8316154: Opensource JTextArea manual tests
• a36d3de: 8328957: Update PKCS11Test.java to not use hardcoded path
• bb046b7: 8320525: G1: G1UpdateRemSetTrackingBeforeRebuild::distribute_marked_bytes accesses partially unloaded klass
• ffdde9c: 8320331: G1 Full GC Heap verification relies on metadata not reset before verification
• d11a065: 8187759: Background not refreshed when painting over a transparent JFrame
• ... and 20 more: https://git.openjdk.org/jdk21u-dev/compare/7743b6ca05b8486eeb38cbbe74569401ce62fe2a...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 41237fc.

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