RFR: 8365057: Add support for java.util.concurrent lock information to Thread.dump_to_file [v2]

[David Holmes]

On Wed, 24 Sep 2025 19:59:55 GMT, Alex Menkov <amenkov at openjdk.org> wrote:

>> The fix updates `jcmd Thread.dump_to_file`/`HotSpotDiagnosticMXBean.dumpThreads` implementation to report thread which owns parkBlocker.
>> 
>> Testing: tier1..4,hs-tier5-svc
>
> Alex Menkov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   feedback

Looks good.

src/jdk.management/share/classes/com/sun/management/doc-files/threadDump.schema.json line 83:

> 81:                           "owner": {
> 82:                             "type": "string",
> 83:                             "description": "The thread identifier of the owner when the parkBlocker is an AbstractOwnableSynchronizer."

Is it possible for there to not be an owner? If so what does this report?

test/jdk/com/sun/management/HotSpotDiagnosticMXBean/DumpThreads.java line 696:

> 694: 
> 695:     /**
> 696:      * Finds the line of plain text thread dump containing the given text.

Suggestion:

     * Finds the line of a plain text thread dump containing the given text.

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PR Review: https://git.openjdk.org/jdk/pull/27457#pullrequestreview-3265266068
PR Review Comment: https://git.openjdk.org/jdk/pull/27457#discussion_r2377469785
PR Review Comment: https://git.openjdk.org/jdk/pull/27457#discussion_r2377472831