8325587: Shenandoah: ShenandoahLock should allow blocking in VM

[mmyxym]

Clean backport of fixing rare long hand shake while mutator threads in heavy contention on ShenandoahLock.

Additional testing:

• Linux aarch64 server fastdebug, hotspot/jtreg/tier1 with +UseShenandoahGC

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8325587 needs maintainer approval

Issue

• JDK-8325587: Shenandoah: ShenandoahLock should allow blocking in VM (Bug - P3 - Approved)

Reviewing

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Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/560/head:pull/560
$ git checkout pull/560

Update a local copy of the PR:
$ git checkout pull/560
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/560/head

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Checkout this PR locally:
$ git pr checkout 560

View PR using the GUI difftool:
$ git pr show -t 560

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https://git.openjdk.org/jdk21u-dev/pull/560.diff

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[bridgekeeper]

👋 Welcome back lmao! 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]

@mmyxym 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:

8325587: Shenandoah: ShenandoahLock should allow blocking in VM

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 223 new commits pushed to the master branch:

• 8c00900: 8315969: compiler/rangechecks/TestRangeCheckHoistingScaledIV.java: make flagless
• d7db5c5: 8320608: Many jtreg printing tests are missing the @printer keyword
• 9a4da24: 8329103: assert(!thread->in_asgct()) failed during multi-mode profiling
• 153accc: 8330849: Add test to verify memory usage with recursive locking
• 99b50b3: 8332248: (fc) java/nio/channels/FileChannel/BlockDeviceSize.java failed with RuntimeException
• 8c6ad58: 8317372: Refactor some NumberFormat tests to use JUnit
• 98cfde4: 8222884: ConcurrentClassDescLookup.java times out intermittently
• 2c3a40b: 8328647: TestGarbageCollectorMXBean.java fails with C1-only and -Xcomp
• c0050ca: 8322062: com/sun/jdi/JdwpAllowTest.java does not performs negative testing with prefix length
• 4be1a02: 8328697: SubMenuShowTest and SwallowKeyEvents tests stabilization
• ... and 213 more: https://git.openjdk.org/jdk21u-dev/compare/93d091ad35cccc9c7010ae6481a61feee7830e92...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.

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➡️ 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]

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

[openjdk]

⚠️ @mmyxym 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.

[mlbridge]

Webrevs

• 00: Full (cb87b771)

[mmyxym]

/approval request Clean backport of fixing rare long hand shake while mutator threads in heavy contention on ShenandoahLock. Risk is quite low.

[openjdk]

@mmyxym
8325587: The approval request has been created successfully.

[GoeLin]

Please backport to 22 first.

[shipilev]

Too early for 21u-dev anyway; there are follow-up improvements that we want to resolve first, and then backport all of them at once, so that JDK 21 is not in some intermediate state.

[RealCLanger]

Too early for 21u-dev anyway; there are follow-up improvements that we want to resolve first, and then backport all of them at once, so that JDK 21 is not in some intermediate state.

Rampdown for 21.0.4 started. So, @shipilev, is it time now to approve this for 21.0.5 or shall we wait?

[shipilev]

Rampdown for 21.0.4 started. So, @shipilev, is it time now to approve this for 21.0.5 or shall we wait?

We are working on JDK-8331411, I would instead prefer wait for that to complete and then backport both back to back.

[RealCLanger]

Rampdown for 21.0.4 started. So, @shipilev, is it time now to approve this for 21.0.5 or shall we wait?

We are working on JDK-8331411, I would instead prefer wait for that to complete and then backport both back to back.

OK, then I'll remove the fix-request label for now. Please re-request when this is ready.

[shipilev]

Hey @mmyxym! I think we are completing our rework of Shenandoah lock, and can therefore proceed with building out the backports. Feel free to re-request this one. We will pile on more backports on top of it.

[mmyxym]

/approval request Clean backport of fixing rare long hand shake while mutator threads in heavy contention on ShenandoahLock. Risk is quite low.

[openjdk]

@mmyxym
8325587: The approval request was already up to date.

[mmyxym]

/integrate

[openjdk]

@mmyxym
Your change (at version cb87b77) is now ready to be sponsored by a Committer.

[shipilev]

/sponsor

[openjdk]

Going to push as commit ad5e16f.
Since your change was applied there have been 228 commits pushed to the master branch:

• 03a7176: 8333099: Missing check for is_LoadVector in StoreNode::Identity
• f9f11d7: 8334867: Add back assertion from JDK-8325494
• 65cf18a: 8328896: Fontmetrics for large Fonts has zero width
• e257ae5: 8051959: Add thread and timestamp options to java.security.debug system property
• 4dceb87: 8321176: [Screencast] make a second attempt on screencast failure
• 8c00900: 8315969: compiler/rangechecks/TestRangeCheckHoistingScaledIV.java: make flagless
• d7db5c5: 8320608: Many jtreg printing tests are missing the @printer keyword
• 9a4da24: 8329103: assert(!thread->in_asgct()) failed during multi-mode profiling
• 153accc: 8330849: Add test to verify memory usage with recursive locking
• 99b50b3: 8332248: (fc) java/nio/channels/FileChannel/BlockDeviceSize.java failed with RuntimeException
• ... and 218 more: https://git.openjdk.org/jdk21u-dev/compare/93d091ad35cccc9c7010ae6481a61feee7830e92...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev @mmyxym Pushed as commit ad5e16f.

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