8326761: Lilliput: OMWorld: Fix invalid markWord transition

[xmas92]

PlaceholderSynchronizer::inflate_and_enter currently performs an invalid transition of the markWord away from monitor. This may lead to an ABA issue.

This got opportunistically added at some point to avoid spinning on the deflation thread progress. The issue of guaranteed progress is not something that has been observed as an issue. If guaranteed progress turns out to be required there are solutions which do not have ABA issues, but it requires extra state in the already heavily contested markWord.

The yielding and spinning will be evaluated in a separate issue.

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Progress

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• Commit message must refer to an issue

Issue

• JDK-8326761: Lilliput: OMWorld: Fix invalid markWord transition (Sub-task - P4)

Reviewers

• Roman Kennke (@rkennke - Reviewer)

Reviewing

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$ git fetch https://git.openjdk.org/lilliput.git pull/138/head:pull/138
$ git checkout pull/138

Update a local copy of the PR:
$ git checkout pull/138
$ git pull https://git.openjdk.org/lilliput.git pull/138/head

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Checkout this PR locally:
$ git pr checkout 138

View PR using the GUI difftool:
$ git pr show -t 138

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https://git.openjdk.org/lilliput/pull/138.diff

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[mlbridge]

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[rkennke]

Looks good! Thanks!

[openjdk]

@xmas92 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:

8326761: Lilliput: OMWorld: Fix invalid markWord transition

Reviewed-by: rkennke

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[xmas92]

/integrate

[openjdk]

Going to push as commit ff713d9.

[openjdk]

@xmas92 Pushed as commit ff713d9.

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