RFR: 8314940: Use of NIO in JDKs Metrics implementation causes issues in GraalVM

[Thomas Stuefe]

On Thu, 24 Aug 2023 13:16:16 GMT, Severin Gehwolf <sgehwolf at openjdk.org> wrote:

> Please review this rather trivial fix to not use `nio` in `CgroupUtil`, part of the
> JDK's Metrics API. The primary motivating factor is that it allows one to use the
> JDK's version of `Metrics` in GraalVM. See the bug for details as to why this is
> needed.
> 
> Testing:
> - [x] GraalVM builds with/without the fix and the reproducer (fails before/works after)
> - [x] `jdk/internal/platform` jtreg tests on Linux x86_64 (cgv1).
> - [x] GHA - passed (Failed GHA cross compile on RISCV is unrelated)

Looks good to me. A comment would be nice, possibly above the imports, warning about using nio.

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Marked as reviewed by stuefe (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/15416#pullrequestreview-1598518803