8314551: More generic way to handshake GC threads with monitor deflation

[shipilev]

Clean backport to to complement JDK-8307236 that is already in JDK 21. There is no bugtail in JDK 22 so far. Attn @rkennke.

Additional testing:

• macos-aarch64-server-fastdebug, hotspot:tier1

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8314551 needs maintainer approval

Issue

• JDK-8314551: More generic way to handshake GC threads with monitor deflation (Bug - P4 - Approved)

Reviewers

• Roman Kennke (@rkennke - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u.git pull/222/head:pull/222
$ git checkout pull/222

Update a local copy of the PR:
$ git checkout pull/222
$ git pull https://git.openjdk.org/jdk21u.git pull/222/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 222

View PR using the GUI difftool:
$ git pr show -t 222

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Download this PR as a diff file:
https://git.openjdk.org/jdk21u/pull/222.diff

Webrev

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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.

[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.

[mlbridge]

Webrevs

• 00: Full (e883f385)

[rkennke]

Looks good to me!

[shipilev]

/approval request Clean backport to to complement JDK-8307236 that is already in JDK 21. There is no bugtail in JDK 22 so far

[openjdk]

@shipilev The approval request has been created successfully.

[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:

8314551: More generic way to handshake GC threads with monitor deflation

Reviewed-by: rkennke

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 no new commits pushed to the master branch. If another commit should be pushed before you perform the /integrate command, your PR will be automatically rebased. If you prefer to avoid any potential 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 6000176.
Since your change was applied there have been 13 commits pushed to the master branch:

• f455049: 8316710: Exclude java/awt/font/Rotate/RotatedTextTest.java
• 6a4e492: 8316879: RegionMatches1Tests fails if CompactStrings are disabled after JDK-8302163
• 915892d: 8313779: RISC-V: use andn / orn in the MD5 instrinsic
• c1f13ea: 8316514: Better diagnostic header for VtableStub
• 69af26c: 8316859: RISC-V: Disable detection of V through HWCAP
• 9ffec67: 8316566: RISC-V: Zero extended narrow oop passed to Atomic::cmpxchg
• 90d4ff6: 8312440: assert(cast != nullptr) failed: must have added a cast to pin the node
• 610f164: 8301247: JPackage app-image exe launches multiple exe's in JDK 17+
• 67d2836: 8315377: C2: assert(u->find_out_with(Op_AddP) == nullptr) failed: more than 2 chained AddP nodes?
• bbfbc7b: 8308103: Massive (up to ~30x) increase in C2 compilation time since JDK 17
• ... and 3 more: https://git.openjdk.org/jdk21u/compare/b12961d94d71c2a06dc1e44ae9c46aaec817e863...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 6000176.

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