[jdk8u-dev] RFR: 8245543: Cgroups: Incorrect detection logic on some systems (still reproducible)

[Severin Gehwolf]

On Mon, 7 Nov 2022 10:30:16 GMT, Jonathan Dowland <jdowland at openjdk.org> wrote:

> A backport of 8245543 to jdk8u-dev for cgroups v2 support.
> 
> Not clean: needed minor adjusting for 8u approach to log output.

Tests will need adjustment for this one.

hotspot/test/runtime/containers/cgroup/CgroupSubsystemFactory.java line 178:

> 176: 
> 177:             cgroupv1MntInfoSystemdOnly = Paths.get(existingDirectory.toString(), "mnt_info_cgroupv1_systemd_only");
> 178:             Files.writeString(cgroupv1MntInfoSystemdOnly, mntInfoCgroupsV1SystemdOnly);

`s/Files.writeString/Files.write`

jdk/test/jdk/internal/platform/cgroup/TestCgroupSubsystemFactory.java line 127:

> 125: 
> 126:             cgroupv1MntInfoSystemdOnly = Paths.get(existingDirectory.toString(), "mountinfo_cgroupv1_systemd_only");
> 127:             Files.writeString(cgroupv1MntInfoSystemdOnly, mntInfoCgroupsV1SystemdOnly);

Same here. Adjust to 8u API (`Files.writeString` not available).

jdk/test/jdk/internal/platform/cgroup/TestCgroupSubsystemFactory.java line 148:

> 146:         Optional<CgroupTypeResult> result = CgroupSubsystemFactory.determineType(mountInfo, cgroups);
> 147: 
> 148:         assertTrue("zero hierarchy ids with no *relevant* controllers mounted", result.isEmpty());

`Optional.isEmpty()` not available in 8u.

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

Changes requested by sgehwolf (Reviewer).

PR: https://git.openjdk.org/jdk8u-dev/pull/159