[crac] RFR: 8373687: [CRaC] Add metrics through jcmd [v5]

[Timofei Pushkin]

On Mon, 22 Dec 2025 19:28:56 GMT, Radim Vansa <rvansa at openjdk.org> wrote:

>> src/hotspot/share/services/diagnosticCommand.cpp line 1092:
>> 
>>> 1090:   const char *metrics = _metrics.value();
>>> 1091:   if (metrics != nullptr) {
>>> 1092:     LocaleGuard lg;
>> 
>> What is the problem with locales? Why is this needed for metrics but not labels?
>
> The problem I've faced with my (czech) locale is that we use comma `,` for decimal point, rather than `.`. Printing and parsing `double` values was using my locale, then, despite from the info I found JDK should setup the C locale at boottime and use that....

Thanks, a comment here would be nice (I see there's one in `image_score.cpp‎` but it won't be trivial to find)

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PR Review Comment: https://git.openjdk.org/crac/pull/281#discussion_r2642214680