8338745: Intrinsify Continuation.pin() and Continuation.unpin()

[mgronlun]

Greetings,

Please help review this change set that implements C2 intrinsics for jdk.internal.vm.Continuation.pin() and jdk.internal.vm.Continuation.unpin().

This work is a consequence of JDK-8338417, which required us to introduce explicit pin constructs for Virtual threads in a relatively performance-sensitive path.

Testing: jdk_jfr, loom testing

Comment: I changed the type of the ContinuationEntry::_pin_count field from uint to uin32_t to make the size explicit and to access it uniformly from the intrinsic code using T_INT.

Thanks
Markus

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
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• Commit message must refer to an issue

Issue

• JDK-8338745: Intrinsify Continuation.pin() and Continuation.unpin() (Enhancement - P3)

Reviewers

• Vladimir Kozlov (@vnkozlov - Reviewer)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/20664/head:pull/20664
$ git checkout pull/20664

Update a local copy of the PR:
$ git checkout pull/20664
$ git pull https://git.openjdk.org/jdk.git pull/20664/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 20664

View PR using the GUI difftool:
$ git pr show -t 20664

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/20664.diff

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[bridgekeeper]

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[openjdk]

@mgronlun 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:

8338745: Intrinsify Continuation.pin() and Continuation.unpin()

Reviewed-by: kvn

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At the time when this comment was updated there had been 5 new commits pushed to the master branch:

• 6cf7f9c: 8338662: Shenandoah: Remove excessive ShenandoahVerifier::verify_during_evacuation
• 129f527: 8338290: Xcode project generator for hotspot
• 6644dd3: 8338760: Adjust the comment after UseObjectMonitorTable
• 1d05989: 8334357: Use NonInterleavingLogStream for report_metadata_oome
• 47c8a6a: 8333265: De-duplicate method references in java.util.stream.FindOps

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
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.

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[openjdk]

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

• core-libs
• graal
• hotspot

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.

[mlbridge]

Webrevs

• 02: Full - Incremental (ba68f2c2)
• 01: Full - Incremental (fa9a737a)
• 00: Full (ab3af53a)

[vnkozlov]

/label remove hotspot

[vnkozlov]

/cc hotspot-compiler

[openjdk]

@vnkozlov
The hotspot label was successfully removed.

[openjdk]

@vnkozlov
The hotspot-compiler label was successfully added.

[mgronlun]

Thank you for your reviews and comments, @vnkozlov, @dean-long, @TobiHartmann and @mur47x111.

[mgronlun]

/integrate

[openjdk]

Going to push as commit fead3cf.
Since your change was applied there have been 14 commits pushed to the master branch:

• a5e2800: 8338834: Remove unused import declarations in java.compiler
• 9cbf685: 8337658: ZGC: Move soft reference handling out of the driver loop function
• 8e0d019: 8338630: Test java/nio/channels/DatagramChannel/SendReceiveMaxSize.java timeout
• e06652a: 8338810: PPC, s390x: LightweightSynchronizer::exit asserts, missing lock
• ea33709: 8328880: Events::log_exception should limit the size of the logging message
• c89a1c3: 8338696: (fs) BasicFileAttributes.creationTime() falls back to epoch if birth time is unavailable (Linux)
• 813546f: 8338856: [BACKOUT] JDK-8337828: CDS: Trim down minimum GC region alignment
• 0b5c887: 8338380: Update TLSCommon/interop/AbstractServer to specify an interface to listen for connections
• 6041c93: 8335664: Parsing jsr broken: assert(bci>= 0 && bci < c->method()->code_size()) failed: index out of bounds
• 6cf7f9c: 8338662: Shenandoah: Remove excessive ShenandoahVerifier::verify_during_evacuation
• ... and 4 more: https://git.openjdk.org/jdk/compare/ab8071d28027ecbf5e8984c30b35fa1c2d934de7...master

Your commit was automatically rebased without conflicts.

[openjdk]

@mgronlun Pushed as commit fead3cf.

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