[11u] RFR: 8255908: ExceptionInInitializerError due to UncheckedIOException while initializing cgroupv1 subsystem

[Severin Gehwolf]

Hi!

Could I please get a review of this bugfix which improves error
checking in the Java Metrics container detection code? The patch is
basically a rewrite, since there is no cgroups v2 in JDK 11, and places
where UncheckedIOException need to be handled are different enough for
the JDK head patch to not apply properly.

The gist is to handle UncheckedIOException, possibly thrown because of
interrupts, and exit gracefully rather than failing to initialize and
crash.

Bug: https://bugs.openjdk.java.net/browse/JDK-8255908
webrev: https://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8255908/01/webrev/

Testing: Container tests on x86_64 Linux (cgroups v1) and tier 1.

Thoughts?

Thanks,
Severin