RFR: JDK-8327769: jcmd GC.heap_dump without options should write to location given by -XX:HeapDumpPath, if set [v10]

[Chris Plummer]

On Thu, 28 Mar 2024 15:08:27 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> Wouldn't this just be a case of changing a flag description? As luck has it, the flag already has a generic name that is not tied to OOMs.

One of the issues with this PR is that there are 7 places where some sort of doc/help update is needed.  The help output for the `filename` option does not work well, because currently it is required option and has no default. This PR sort of gives it a default, but not always, so the default needs to be given in descriptive way , but jcmd help is not really setup to handle descriptive defaults, so we end up with this:

_filename("filename","Name of the dump file", "STRING", false, "if no filename was specified, but -XX:HeapDumpPath=hdp is set, path hdp is taken"),

And even this is not complete. HeapDumpPath can be a directory, in which case a filename is generated using the PID and a dump sequence number. Probably all this belongs in the argument description, which currently just says "Name of dump file", but you still need to put something in for the default. If the description is complete, maybe just using "See description" would be better.

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PR Comment: https://git.openjdk.org/jdk/pull/18190#issuecomment-2026614466