8317262: LockStack::contains(oop) fails "assert(t->is_Java_thread()) failed: incorrect cast to JavaThread"

[shipilev]

Clean backport to fix the trivial bug in new light-weight locking. This code path is disabled by default in JDK 21u, but the bug would manifest if any user experimentally enables it.

Additional testing:

• New regression test fails without the patch, passes with it (needs explicit -XX:LockingMode=2 to reproduce)

---

Progress

• Change must not contain extraneous whitespace
• JDK-8317262 needs maintainer approval
• Commit message must refer to an issue

Issue

• JDK-8317262: LockStack::contains(oop) fails "assert(t->is_Java_thread()) failed: incorrect cast to JavaThread" (Bug - P3 - Approved)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk21u.git pull/262/head:pull/262
$ git checkout pull/262

Update a local copy of the PR:
$ git checkout pull/262
$ git pull https://git.openjdk.org/jdk21u.git pull/262/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 262

View PR using the GUI difftool:
$ git pr show -t 262

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk21u/pull/262.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.

[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.

[shipilev]

/approval request Clean backport to fix the trivial bug in new light-weight locking. This code path is disabled by default in JDK 21u, but the bug would manifest if any user experimentally enables it.

[mlbridge]

Webrevs

• 00: Full (8e2bb563)

[openjdk]

@shipilev
8317262: 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:

8317262: LockStack::contains(oop) fails "assert(t->is_Java_thread()) failed: incorrect cast to JavaThread"

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 18 new commits pushed to the master branch:

• e796082: Merge
• 060c4f7: 8317121: vector_masked_load instruction is moved too early after JDK-8286941
• 587a7ca: Merge
• 9ebc5ac: 8314649: Enhanced archival support redux
• 86a1699: 8309966: Enhanced TLS connections
• 5f5061f: 8312248: Enhanced archival support redux
• 091ebfa: 8311682: Change milestone to fcs for all releases
• b293106: 8286503: Enhance security classes
• 8b58728: Merge remote-tracking branch 'jdk21u/master'
• 0ca350d: 8297856: Improve handling of Bidi characters
• ... and 8 more: https://git.openjdk.org/jdk21u/compare/65941f8d31094511a5bf8dff110645f83cfc07ef...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]

/integrate

[openjdk]

Going to push as commit 94bb191.
Since your change was applied there have been 21 commits pushed to the master branch:

• 7b4ab28: 8295068: SSLEngine throws NPE parsing CertificateRequests
• 87ca293: 8309663: test fails "assert(check_alignment(result)) failed: address not aligned: 0x00000008baadbabe"
• 55d0c79: 8316929: Shenandoah: Shenandoah degenerated GC and full GC need to cleanup old OopMapCache entries
• e796082: Merge
• 060c4f7: 8317121: vector_masked_load instruction is moved too early after JDK-8286941
• 587a7ca: Merge
• 9ebc5ac: 8314649: Enhanced archival support redux
• 86a1699: 8309966: Enhanced TLS connections
• 5f5061f: 8312248: Enhanced archival support redux
• 091ebfa: 8311682: Change milestone to fcs for all releases
• ... and 11 more: https://git.openjdk.org/jdk21u/compare/65941f8d31094511a5bf8dff110645f83cfc07ef...master

Your commit was automatically rebased without conflicts.

[openjdk]

@shipilev Pushed as commit 94bb191.

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