RFR: 8332105: Exploded JDK does not include CDS

[David Holmes]

On Sat, 11 May 2024 06:13:29 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> An exploded JDK cannot be used with either -Xshare:on or -Xshare:auto. That causes tests like runtime/CompressedOops/CompressedCPUSpecificClassSpaceReservation.java to fail when running on an exploded JDK.
> 
> Since an exploded JDK cannot use CDS, we should - for tests - treat it as if CDS had not been included.
> 
> 
> ----
> 
> Note that I was torn between two ways to fix this:
> 
> - either this fix, which is rather simple and automatically updates the "vm.cds" `@requires` property
> - or to expose "exploded-ness" as a boolean property via `WhiteBox` and `VMProps`(`jdk.exploded`). See this draft PR: https://github.com/openjdk/jdk/pull/19178 . 
> 
> The latter is cleaner and clearer, conveying the message of exploded-ness without muddling it with the CDS aspect. But OTOH the complexity may not be required. 
> 
> I can go either way, though I have a slight preference for this PR, which is why I posted it.

Seems okay. This test should have had  `requires vm.cds` anyway.

Just out of curiosity why is CDS not compatible with an exploded build?

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Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/19188#pullrequestreview-2080060349