[jdk11u-dev] RFR: 8231111: Cgroups v2: Rework Metrics in java.base so as to recognize unified hierarchy [v8]

[Zhengyu Gu]

> This is a followup backport for Cgroup v2 support.
> 
> The original patch does not apply cleanly, due to context differences and some of out-of-order backports, conflicts were resolved manually.
> 
> In additional:
> 
> 1) Include partial backport of JDK-8250627.
>     - Renamed `Metrics.c` =>  `CgroupMetrics.c`
>     - Added native method `isUseContainerSupport()` to `CgroupMetrics.java`
>     - Return instance only if `isUseContainerSupport()` is enabled.
>    
> 2) Add `createTempDirectory()` method to `test/lib/jdk/test/lib/Utils.java` for `TestCgroupSubsystemController.java` test
> 
> 3) Add `import jdk.test.lib.process.OutputAnalyzer;` to `TestDockerMemoryMetrics.java`
> 
> Test:
> 
> - [x] jtreg containers/docker test on Ubuntu 20.04.4 LTS
> - [x] jdk/internal/platform/cgroup on Ubuntu 20.04.4 LTS
> - [x] jdk/internal/platform/docker on Ubuntu 20.04.4 LTS

Zhengyu Gu has updated the pull request incrementally with eight additional commits since the last revision:

 - Merge
 - Merge branch 'master' into backport-8230305-cgroup-v2
 - 8223396: [TESTBUG] several jfr tests do not clean up files created in /tmp
   
   Using test utils to create temp files and directories
   
   Reviewed-by: sgehwolf
   Backport-of: 7d3aebccc0b90aa2ca2f656c683fa5931fd0ed3a
 - 8247592: refactor test/jdk/tools/launcher/Test7029048.java
   
   Reviewed-by: phh
   Backport-of: 8b87402a4409b345b820207dcd2aec720a23325b
 - 8166727: javac crashed: [jimage.dll+0x1942]  ImageStrings::find+0x28
   
   Backport-of: a8005efde388821e39e6464dbb17fbeac3c9830a
 - 8279356: Method linking fails with guarantee(mh->adapter() != NULL) failed: Adapter blob must already exist!
   
   Reviewed-by: phh
   Backport-of: 6d7db4b0b3e9172645cef12c36fbeb41a6d38d83
 - 8199874: [TESTBUG] runtime/Thread/ThreadPriorities.java fails with "expected 0 to equal 10"
   
   Backport-of: 0d9f615e9214ed6f1f69f6e7969e966005948eb3
 - 8207364: nsk/jvmti/ResourceExhausted/resexhausted003 fails to start
   
   Backport-of: 31cf8b1c65fb0b19e093547fc557fff55d7213bd

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

Changes:
  - all: https://git.openjdk.java.net/jdk11u-dev/pull/863/files
  - new: https://git.openjdk.java.net/jdk11u-dev/pull/863/files/7d276fe6..3e4a0b42

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=863&range=07
 - incr: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=863&range=06-07

  Stats: 211 lines in 18 files changed: 92 ins; 64 del; 55 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/863.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/863/head:pull/863

PR: https://git.openjdk.java.net/jdk11u-dev/pull/863