8290234: [JVMCI] use JVMCIKlassHandle to protect raw Klass* values from concurrent G1 scanning

[dougxc]

JVMCI Java code must never read a raw Klass* value from memory (using Unsafe) that is not already known to be wrapped in a HotSpotResolvedObjectTypeImpl without going through a VM call. The VM call is necessary so that the Klass* is handlized in a JVMCIKlassHandle to protect it from the concurrent scanning done by G1. This PR re-introduces the VM calls that were mistakenly optimized away in JDK-8289094.

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Progress

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Issue

• JDK-8290234: [JVMCI] use JVMCIKlassHandle to protect raw Klass* values from concurrent G1 scanning

Reviewers

• Vladimir Kozlov (@vnkozlov - Reviewer)
• Tom Rodriguez (@tkrodriguez - Reviewer)

Reviewing

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$ git checkout pull/9480

Update a local copy of the PR:
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$ git pull https://git.openjdk.org/jdk pull/9480/head

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$ git pr checkout 9480

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[bridgekeeper]

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[openjdk]

@dougxc The following label will be automatically applied to this pull request:

• hotspot-compiler

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[mlbridge]

Webrevs

• 00: Full (9c6f9f79)

[vnkozlov]

Good.

[openjdk]

@dougxc 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:

8290234: [JVMCI] use JVMCIKlassHandle to protect raw Klass* values from concurrent G1 scanning

Reviewed-by: kvn, never

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 4 new commits pushed to the master branch:

• 2583feb: 8290023: Remove use of IgnoreUnrecognizedVMOptions in gc tests
• 44fb92e: 8290197: test/jdk/java/nio/file/Files/probeContentType/Basic.java fails on some systems for the ".rar" extension
• f528124: 8289284: jdk.tracePinnedThreads output confusing when pinned due to native frame
• 572c14e: 8288624: Cleanup CommentHelper.getText0

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.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[dougxc]

Thanks for the reviews.

[dougxc]

/integrate

[openjdk]

Going to push as commit 74ac5df.
Since your change was applied there have been 6 commits pushed to the master branch:

• 5e3ecff: 8290253: gc/g1/TestVerificationInConcurrentCycle.java#id1 fails with "Error. can't find sun.hotspot.WhiteBox in test directory or libraries"
• 5358045: 8066859: java/lang/ref/OOMEInReferenceHandler.java failed with java.lang.Exception: Reference Handler thread died
• 2583feb: 8290023: Remove use of IgnoreUnrecognizedVMOptions in gc tests
• 44fb92e: 8290197: test/jdk/java/nio/file/Files/probeContentType/Basic.java fails on some systems for the ".rar" extension
• f528124: 8289284: jdk.tracePinnedThreads output confusing when pinned due to native frame
• 572c14e: 8288624: Cleanup CommentHelper.getText0

Your commit was automatically rebased without conflicts.

[openjdk]

@dougxc Pushed as commit 74ac5df.

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