8275277: assert(dest_attr.is_in_cset() == (obj->forwardee() == obj)) failed: Only evac-failed objects must be in the collection set here but <addr> is not

[tschatzl]

Hi all,

can I have reviews for this fix of an incomplete assert?

When checking whether the forwardee equals the object, we first need to check whether the object is already forwarded, otherwise we might get false positives. See CR for more details (example).

Testing: gha, failing tests do not fail after 2k repetitions

Thanks,
Thomas

---

Progress

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Issue

• JDK-8275277: assert(dest_attr.is_in_cset() == (obj->forwardee() == obj)) failed: Only evac-failed objects must be in the collection set here but is not

Reviewers

• Albert Mingkun Yang (@albertnetymk - Reviewer)
• Roman Kennke (@rkennke - Reviewer)

Reviewing

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[mlbridge]

Webrevs

• 00: Full (979d25f5)

[albertnetymk]

Ofc obj could be outside cset, and it's dangerous to call forwardee directly... Thank you for the analysis and the fix.

[openjdk]

@tschatzl 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:

8275277: assert(dest_attr.is_in_cset() == (obj->forwardee() == obj)) failed: Only evac-failed objects must be in the collection set here but <addr> is not

Reviewed-by: ayang, rkennke

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 3 new commits pushed to the master branch:

• 172aed1: 8274338: com/sun/jdi/RedefineCrossEvent.java failed "assert(m != __null) failed: NULL mirror"
• ced7909: 8275286: Check current thread when calling JRT methods that expect it
• c0f3e1d: 8271071: accessibility of a table on macOS lacks cell navigation

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.

[rkennke]

I've stumbled over the same thing, and came up with same solution. Looks good!

[tschatzl]

Thanks @albertnetymk @rkennke for your reviews.

/integrate

[openjdk]

Going to push as commit bfcf6a2.
Since your change was applied there have been 12 commits pushed to the master branch:

• 96fef40: 8189591: No way to locally suppress doclint warnings
• 7fc3a8d: 8275149: (ch) ReadableByteChannel returned by Channels.newChannel(InputStream) throws ReadOnlyBufferException
• 831802d: 8275163: Deflater::deflate methods omit javadoc for ReadOnlyBufferException
• ad9e234: 8275145: file.encoding system property has an incorrect value on Windows
• f178185: 8275249: Suppress warnings on non-serializable array component types in jdk.jlink
• ee64ce9: 8274937: Revert the timeout setting for DynamicLoaderConstraintsTest
• 8c4da9c: 8275013: Improve discussion of serialization method declarations in java.io.Object{Input, Output}Stream
• da8da3a: 8269698: Specification for methods of java.awt.im.InputContext should mention that they do nothing
• 8e02064: 8049520: FileCredentialsCache loads cache once and is never refreshed
• 172aed1: 8274338: com/sun/jdi/RedefineCrossEvent.java failed "assert(m != __null) failed: NULL mirror"
• ... and 2 more: https://git.openjdk.java.net/jdk/compare/4cb7124c1e9c5fd1d3a82fd8933cc63fefde9531...master

Your commit was automatically rebased without conflicts.

[openjdk]

@tschatzl Pushed as commit bfcf6a2.

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