8373120: Virtual thread stuck in BLOCKED state

[shipilev]

Fixes another Virtual Thread issue that manifests in JDK 25.

Unfortunately, JDK-8369238 adjusted the same block (added interruptible flag). That issue is too large to backport at this time. We might backport it later. But we can fix this particular issue by carefully dealing with interruptible conflict. The code shape looks to be the same and fixes the reproducer.

Additional testing:

• New regression test fails without the fix, passes with it; 1000x iterations
• Linux x86_64 server fastdebug, jdk_loom hotspot_loom, 100x
• Linux x86_64 server fastdebug, java/lang/Thread/virtual/stress/, 500x
• Linux AArch64 server fastdebug, all

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Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• JDK-8373120 needs maintainer approval
• Commit message must refer to an issue

Issue

• JDK-8373120: Virtual thread stuck in BLOCKED state (Bug - P3)

Reviewers

• Patricio Chilano Mateo (@pchilano - no project role)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk25u-dev.git pull/379/head:pull/379
$ git checkout pull/379

Update a local copy of the PR:
$ git checkout pull/379
$ git pull https://git.openjdk.org/jdk25u-dev.git pull/379/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 379

View PR using the GUI difftool:
$ git pr show -t 379

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk25u-dev/pull/379.diff

Using 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.

[shipilev]

@pchilano, would be happy to hear what you think here :)

[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

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

[mlbridge]

Webrevs

• 00: Full (a2a0d68c)

[pchilano]

Looks good, thanks for backporting!

[shipilev]

Thank you for looking! I'll stress test it a bit more and then request approval for 25u.

[shipilev]

Stress tests pass, see PR body. Oh, but we should do JDK 26 first: openjdk/jdk26u#111