RFR: 8271242: Add Arena regression tests

[Mikhailo Seledtsov]

On Tue, 27 Jul 2021 06:06:40 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> May I please have reviews for these test additions. These are new regression tests for hotspot arenas. We don't have any and it makes sense to have them since this code is fragile and we work on it.
> 
> It also contains some new gtest utility functions which I will use to consolidate some more test coding, mainly in the metaspace gtests (in a future rfe).
> 
> It also comes with a new jtreg gtest launcher for arena tests to test UseMallocOnly mode. As long as we support that, we should test it.
> 
> ---
> 
> tests: 
> - gtests, manually with 32/64 bit and with/without UseMallocOnly
> - GHAs

Thank you for adding these tests. These new tests look good to me (from HotSpot test engineer POV). Someone who is an expert in Arena allocation should review this change as well.

test/hotspot/jtreg/gtest/ArenaGtests.java line 38:

> 36:  * @modules java.base/jdk.internal.misc
> 37:  *          java.xml
> 38:  * @requires vm.flagless

Style comment: Please group all at-requires together in the same or neighboring lines.

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

Marked as reviewed by mseledtsov (Committer).

PR: https://git.openjdk.java.net/jdk/pull/4909