jmx-dev RFR: 8373441: Remove DCmdFactory::_enabled [v2]

[Frederic Parain]

On Fri, 12 Dec 2025 23:37:20 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> The `DCmdFactory::_enabled` is always set to `true` and there doesn't seem to be a reason to set it to `false`.
>> 
>> This PR removes this field and simplified the creation of `DCmdFactory` objects.
>> 
>> The related `_hidden` field is also currently not used, but may be used in the future when deprecating DCmds, so we leave it unchanged.
>> 
>> Note that now `jmm_GetDiagnosticCommandInfo()` always set `dcmdInfo::enabled` to `true` to be compatible with Java code.
>
> Ioi Lam has updated the pull request incrementally with one additional commit since the last revision:
> 
>   @kevinjwalls comments

The "enabled" capability probably fall in the category of features that were initially implemented to emulate JRockit jrcmd  tool but were finally not integrated in HotSpot (I remember another feature like that, to execute an user shell script when some events were triggered).
I don't remember having used or debugged this enable/disable feature. It looks that dead code that have been here for too long. Thank you for having found it and cleaned it up.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/28794#issuecomment-3661116214