8382242: JFR: Metadata reconstruction invalidates ConstantMap for java.lang.String

[mgronlun]

Greetings,

JFR Metadata reconstruction invalidates the existing ConstantMap for java.lang.String.

The effect of this is that JFR StringPool data is discarded, and so subsequent references from events to strings supposed to exist in the string pool, via string id lookup, fail (return null).

The existing ConstantLookup for java.lang.String should be reused when creating a new StringParser.

Testing: jdk_jfr

Thanks
Markus

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Issue

• JDK-8382242: JFR: Metadata reconstruction invalidates ConstantMap for java.lang.String (Bug - P2)

Reviewers

• Erik Gahlin (@egahlin - Reviewer)

Reviewing

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

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After integration, the commit message for the final commit will be:

8382242: JFR: Metadata reconstruction invalidates ConstantMap for java.lang.String

Reviewed-by: egahlin

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At the time when this comment was updated there had been 85 new commits pushed to the master branch:

• 26df25e: 8382045: Increase AOT C strings table size in not product VM
• 04bb3a9: 8381176: Utilities.expectedNegoAppProtocol chooses client ALPN protocol over server's
• 8688c0b: 8379129: C2 crash in LoadNode::can_split_through_phi_base during Escape Analysis (JDK 25.0.1+8)
• ... and 82 more: https://git.openjdk.org/jdk/compare/d471f474994b868bbfb2d18a10f6996c900a59bc...master

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[mlbridge]

Webrevs

• 02: Full - Incremental (032cb898)
• 01: Full - Incremental (137dfdd6)
• 00: Full (af6aa1a9)

[arouel]

@mgronlun thank you for proposing a patch

[mgronlun]

Thank you @egahlin for your review and @arouel for contributing.

[mgronlun]

/integrate

[openjdk]

Going to push as commit ca64301.
Since your change was applied there have been 101 commits pushed to the master branch:

• 15a7eab: 8381924: Fix include guard in lambdaProxyClassDictionary.hpp
• 5c403a8: 8380912: "Trailing white space will be removed" incorrectly triggered with \u2028
• 2999731: 8382295: Shenandoah: wrong denominator in full gc summary
• ... and 98 more: https://git.openjdk.org/jdk/compare/d471f474994b868bbfb2d18a10f6996c900a59bc...master

Your commit was automatically rebased without conflicts.

[openjdk]

@mgronlun Pushed as commit ca64301.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

[mgronlun]

/backport :jdk26

[openjdk]

@mgronlun the backport was successfully created on the branch backport-mgronlun-ca643010-jdk26 in my personal fork of openjdk/jdk. To create a pull request with this backport targeting openjdk/jdk:jdk26, just click the following link:

➡️ Create pull request

The title of the pull request is automatically filled in correctly and below you find a suggestion for the pull request body:

Hi all,

This pull request contains a backport of commit ca643010 from the openjdk/jdk repository.

The commit being backported was authored by Markus Grönlund on 17 Apr 2026 and was reviewed by Erik Gahlin.

Thanks!

If you need to update the source branch of the pull then run the following commands in a local clone of your personal fork of openjdk/jdk:

$ git fetch https://github.com/openjdk-bots/jdk.git backport-mgronlun-ca643010-jdk26:backport-mgronlun-ca643010-jdk26
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$ git commit --message 'Describe additional changes made'
$ git push https://github.com/openjdk-bots/jdk.git backport-mgronlun-ca643010-jdk26

[mgronlun]

/backport :jdk26u

[openjdk]

@mgronlun The target branch jdk26u does not exist
List of valid branches: master, jdk26, jdk25, jdk24, jdk23.

[mgronlun]

/backport jdk26u

[openjdk]

@mgronlun the backport was successfully created on the branch backport-mgronlun-ca643010-master in my personal fork of openjdk/jdk26u. To create a pull request with this backport targeting openjdk/jdk26u:master, just click the following link:

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The title of the pull request is automatically filled in correctly and below you find a suggestion for the pull request body:

Hi all,

This pull request contains a backport of commit ca643010 from the openjdk/jdk repository.

The commit being backported was authored by Markus Grönlund on 17 Apr 2026 and was reviewed by Erik Gahlin.

Thanks!

If you need to update the source branch of the pull then run the following commands in a local clone of your personal fork of openjdk/jdk26u:

$ git fetch https://github.com/openjdk-bots/jdk26u.git backport-mgronlun-ca643010-master:backport-mgronlun-ca643010-master
$ git checkout backport-mgronlun-ca643010-master
# make changes
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$ git commit --message 'Describe additional changes made'
$ git push https://github.com/openjdk-bots/jdk26u.git backport-mgronlun-ca643010-master

⚠️ @mgronlun You are not yet a collaborator in my fork openjdk-bots/jdk26u. An invite will be sent out and you need to accept it before you can proceed.