[lworld] RFR: 8372261: [lworld] Augment vmTestbase array tests with large flat arrays [v2]

[Paul Hübner]

On Fri, 13 Feb 2026 15:48:18 GMT, Leonid Mesnik <lmesnik at openjdk.org> wrote:

>> test/hotspot/jtreg/vmTestbase/nsk/share/gc/Memory.java line 40:
>> 
>>> 38:         private static int objectExtraSize = 0;
>>> 39: 
>>> 40:         private static final boolean previewEnabled =
>> 
>> I think there are some more robust ways to check for preview.
>> * The best way is probably `jdk.internal.misc.PreviewFeatures.isEnabled` which checks if the current VM is preview-enabled. Needs `@modules java.base/jdk.internal.misc`. 
>> * Alternatively, if the above is not possible, `jdk.test.lib.Utils.getTestJavaOpts` which you can check in a Stream for `--enable-preview`. This consolidates all of the `test.vm.opts` and `test.java.opts` for you.
>
> That's an actual problem with these vmTestbase jtreg tests.
> To use jdk.internal.misc.PreviewFeatures.isEnabled it is needed to add `@modules java.base/jdk.internal.misc`to every test. The same for `jdk.test.lib.Utils.getTestJavaOpts`. It is needed to ensure that `/test/lib` is used by every test. 
> 
> This file has `TODO: somehow determine the real value`.
> It would be really great  to find single solution. I wonder if run something like VMProps in external process to obtain data would be better solution. So we don't need to change every single test.

I understand. Maybe we can check both `test.java.opts` and `test.vm.opts` for `--enable-preview` then? I'm not sure we check for `--preview` anywhere else.

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PR Review Comment: https://git.openjdk.org/valhalla/pull/2099#discussion_r2804890326