8371474: Wrong object class or methodID passed to JNI call in TestSharedCloseJvmti with -Xshare:off

[JornVernee]

The existing test uses the JVMTI VMStart callback to look up a class. This works when using CDS, because the class is already available, but because VMStart is called while the VM is still being initialized, it fails to find the target class when CDS is turned off.

Instead, the VMInit callback should be used, which runs after the VM has been initialized. This patch does this. Additionally, it delays the call to allocate OTHER_SEGMENT. If we call FindClass during VMInit, the <clinit> of the class will run, which then ends up calling checkValidStateRaw as a result of allocating OTHER_SEGMENT, and we get to our method exit event code before the target class and method ID have been initialized.

As a side note: I had know about the difference between VMInit and VMStart, and had actually intended to use VMInit in the first place, but I seem to have gotten the two confused, because they are listed in reverse chronological order in the list under 'Set Event Notification Mode' in the JVMTI spec (https://docs.oracle.com/en/java/javase/25/docs/specs/jvmti.html#SetEventNotificationMode).

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Issue

• JDK-8371474: Wrong object class or methodID passed to JNI call in TestSharedCloseJvmti with -Xshare:off (Bug - P4)

Reviewers

• Alan Bateman (@AlanBateman - Reviewer)
• Martin Doerr (@TheRealMDoerr - Reviewer)

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[openjdk]

@JornVernee This change now passes all automated pre-integration checks.

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8371474: Wrong object class or methodID passed to JNI call in TestSharedCloseJvmti with -Xshare:off

Reviewed-by: alanb, mdoerr

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At the time when this comment was updated there had been 23 new commits pushed to the master branch:

• 98f40e4: 8371425: Include folder names in vscode workspace virtual folders
• 681dab7: 8365972: JFR: ThreadDump and ClassLoaderStatistics events may cause back to back rotations
• 49f51f9: 8370612: Simplify implementation of dark theme
• ... and 20 more: https://git.openjdk.org/jdk/compare/d5803aa78a84caccd5c3f14ac788817c5a3b4725...master

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[AlanBateman]

Yes, using VMInit so the code executes when the VM is fully initialized is right.

[TheRealMDoerr]

LGTM and fixes the issue. Thanks!

[JornVernee]

LGTM and fixes the issue. Thanks!

Thanks for the initial investigation!

[JornVernee]

/integrate

[openjdk]

Going to push as commit 6e838d6.
Since your change was applied there have been 27 commits pushed to the master branch:

• 2d4f2fd: 8349732: Add support for JARs signed with ML-DSA
• 1877ff9: 8331195: Improve com.sun.net.httpserver.HttpExchange usability
• 9d2fa8f: 8371321: Remove unused last arg of BarrierSetAssembler::arraycopy_epilogue
• ... and 24 more: https://git.openjdk.org/jdk/compare/d5803aa78a84caccd5c3f14ac788817c5a3b4725...master

Your commit was automatically rebased without conflicts.

[openjdk]

@JornVernee Pushed as commit 6e838d6.

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