RFR: 8372615: Many container tests fail when running rootless on cgroup v1 [v2]

[Casper Norrbin]

On Mon, 1 Dec 2025 04:18:47 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Casper Norrbin has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   reworked check docker/resourcelimit functions
>
> test/lib/jdk/test/lib/containers/docker/DockerTestUtils.java line 142:
> 
>> 140:      *
>> 141:      * @return true if resource limits are supported in the current configuration
>> 142:      * @throws Exception
> 
> I don't like this pattern of making a function seem like it is a query by declaring it returns a boolean when in reality it either returns true or else throws. These should just be void functions with names like `checkCanUseResourceLimits`, and we can elide the fake `if` conditions with unreachable `return` statements in the callers.

I agree that it could be made clearer.

I reworked both `canUseResourceLimits()` and `canTestDocker()` into `void` functions that only throw. So 

```c++
if (!DockerTestUtils.canTestDocker() || !DockerTestUtils.canUseResourceLimits()) {
    return;
}


Instead becomes:

```c++
DockerTestUtils.checkCanTestDocker();
DockerTestUtils.checkCanUseResourceLimits();

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

PR Review Comment: https://git.openjdk.org/jdk/pull/28557#discussion_r2576955639