RFR: 8287073: NPE from CgroupV2Subsystem.getInstance() [v2]

[Maxim Kartashev]

On Thu, 26 May 2022 15:25:32 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> Maxim Kartashev has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Removed unnecessary null checks
>
> src/java.base/linux/classes/jdk/internal/platform/CgroupSubsystemFactory.java line 113:
> 
>> 111:             CgroupInfo anyController = infos.values().iterator().next();
>> 112:             CgroupSubsystem subsystem = CgroupV2Subsystem.getInstance(anyController);
>> 113:             return new CgroupMetrics(subsystem);
> 
> Should add `Objects.requireNonNull(anyController)` and `Objects.requireNonNull(subsystem)`.

I added the first, but not the second as that looks like an overkill; see the definition of the constructor:

    CgroupMetrics(CgroupSubsystem subsystem) {
        this.subsystem = Objects.requireNonNull(subsystem);
    }

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

PR: https://git.openjdk.java.net/jdk/pull/8803