8373944: ObjectMonitor::ExitOnSuspend can call java_lang_VirtualThread::set_onWaitingList() while in safepoint

[pchilano]

This pull request contains a backport of commit 4b99aef1 from the openjdk/jdk repository.

Thanks,
Patricio

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8373944 needs maintainer approval

Issue

• JDK-8373944: ObjectMonitor::ExitOnSuspend can call java_lang_VirtualThread::set_onWaitingList() while in safepoint (Bug - P2 - Approved)

Reviewing

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Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk26u.git pull/91/head:pull/91
$ git checkout pull/91

Update a local copy of the PR:
$ git checkout pull/91
$ git pull https://git.openjdk.org/jdk26u.git pull/91/head

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$ git pr checkout 91

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https://git.openjdk.org/jdk26u/pull/91.diff

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[bridgekeeper]

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[openjdk]

@pchilano This change is no longer ready for integration - check the PR body for details.

[openjdk]

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

[pchilano]

/approval request This fixes a bug where oops might be touched by a JavaThread while a safepoint is in progress. The fix is simple and only touches method ObjectMonitor::ExitOnSuspend::operator(), where a safepoint poll is added, plus an extra assert in ObjectMonitor::exit_epilog. The fix applies cleanly. It includes a new test which reliably reproduces the issue.

[openjdk]

@pchilano
8373944: The approval request has been created successfully.

[mlbridge]

Webrevs

• 00: Full (a7e87c67)