8321270: Virtual Thread.yield consumes parking permit

[AlanBateman]

When a virtual thread continues after Thread.yield it currently consumes thread's parking permit. This is an oversight, the parking permit should only be consumed when continuing after park.

The changes are straight-forward. The internal "RUNNABLE" state is replaced with UNPARKED and YIELDED state, effectively encoding the previous state. So for the most part, it's just replacing the usages of RUNNABLE. The additional states require refactoring tryGetStackTrace, this is the method that is used for Thread::getStackTrace when the virtual thread is unmounted. It is also changed to not not swallow the REE if the reesubmit fails (tryStackTrace has to resubmit as the task for the thread may run, or the thread unparked, while "suspended" and sampling its stack trace). The changes are a subset of larger changes in the loom repo, future PRs will propose to bring in other changes to get main line up to date.

For testing the existing ThreadAPI has new test cases.

Testing: test1-5. This includes the JVMTI tests as it maps the thread states to JVMTI thread states.

---

Progress

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

Issue

• JDK-8321270: Virtual Thread.yield consumes parking permit (Bug - P4)

Reviewers

• Serguei Spitsyn (@sspitsyn - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/16953/head:pull/16953
$ git checkout pull/16953

Update a local copy of the PR:
$ git checkout pull/16953
$ git pull https://git.openjdk.org/jdk.git pull/16953/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 16953

View PR using the GUI difftool:
$ git pr show -t 16953

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/16953.diff

Webrev

Link to Webrev Comment

[bridgekeeper]

👋 Welcome back alanb! 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]

@AlanBateman The following labels will be automatically applied to this pull request:

• core-libs
• hotspot-runtime

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing lists. If you would like to change these labels, use the /label pull request command.

[AlanBateman]

/label add serviceability
/label remove hotspot-runtime

[openjdk]

@AlanBateman
The serviceability label was successfully added.

[openjdk]

@AlanBateman
The hotspot-runtime label was successfully removed.

[mlbridge]

Webrevs

• 01: Full - Incremental (057c9a57)
• 00: Full (45c6072a)

[sspitsyn]

The fix looks good to me.
Also, it can be more safe to run mach5 tier6 as well.

[openjdk]

@AlanBateman 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:

8321270: Virtual Thread.yield consumes parking permit

Reviewed-by: sspitsyn

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 23 new commits pushed to the master branch:

• 9e57010: 8315149: Add hsperf counters for CPU time of internal GC threads
• b0d1450: 8321053: Use ByteArrayInputStream.buf directly when parameter of transferTo() is trusted
• acaf2c8: 8318590: JButton ignores margin when painting HTML text
• d3df3eb: 8294699: Launcher causes lingering busy cursor
• fddc02e: 8321225: [JVMCI] HotSpotResolvedObjectTypeImpl.isLeafClass shouldn't create strong references
• 640d7f3: 8314327: Issues with JShell when using "local" execution engine
• db5613a: 8317288: [macos] java/awt/Window/Grab/GrabTest.java: Press on the outside area didn't cause ungrab
• b1cb374: 8320349: Simplify FileChooserSymLinkTest.java by using single-window testUI
• 18c7922: 8321224: ct.sym for JDK 22 contains references to internal modules
• 83ffc1a: 8320303: Allow PassFailJFrame to accept single window creator
• ... and 13 more: https://git.openjdk.org/jdk/compare/aec386596d531345b46be4f674b775df71df1eee...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.

[dholmes-ora]

Sorry I've deleted my earlier embarassingly stupid comment. The key point of this change is to split RUNNABLE into two states to indicated "runnable after yielding" and "runnable after being unparked".

[AlanBateman]

The key point of this change is to split RUNNABLE into two states to indicated "runnable after yielding" and "runnable after being unparked".

That's right. This comes up with upcoming changes for monitors too - in that case it is important that a virtual thread that continues after blocking on monitorenter doesn't consume its parking permit.

[AlanBateman]

/integrate

[openjdk]

Going to push as commit 29d7a22.
Since your change was applied there have been 59 commits pushed to the master branch:

• 0b0fa47: 8319925: CSS.BackgroundImage incorrectly uses double-checked locking
• 0048f1d: 8263256: Test java/net/Inet6Address/serialize/Inet6AddressSerializationTest.java fails due to dynamic reconfigurations of network interface during test
• 49fff01: 8211238: @deprecated JFR event
• 656b446: 8320969: Shenandoah: Enforce stable number of GC workers
• 9a87e52: 8320538: Obsolete CSS styles in collection framework doc-file
• 03c4595: 8321164: javac with annotation processor throws AssertionError: Filling jrt:/... during JarFileObject[/...]
• 632a3c5: 8305825: getBounds API returns wrong value resulting in multiple Regression Test Failures on Ubuntu 23.04
• 75a7c19: 8315827: Kitchensink.java and RenaissanceStressTest.java time out with jvmti module errors
• 91ffdfb: 8320365: IPPPrintService.getAttributes() causes blanket re-initialisation
• 50baaf4: 8321013: Parallel: Refactor ObjectStartArray
• ... and 49 more: https://git.openjdk.org/jdk/compare/aec386596d531345b46be4f674b775df71df1eee...master

Your commit was automatically rebased without conflicts.

[openjdk]

@AlanBateman Pushed as commit 29d7a22.

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