RFR: 8371629: Add diagnostic output IPSupport.printPlatformSupport(System.out) to tests in java/nio/channels directory -- part I

[Mark Sheppard]

On Thu, 20 Nov 2025 11:57:35 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:

>> Add diagnostic output IPSupport.printPlatformSupport(System.out) to tests in java/nio/channels directory -- part I
>
> Hello Serhiy, my opinion is that we shouldn't be adding this change to every single test file.
> When a test is run, typically in CI or locally, it runs as part of several other tests on a specific host. The `IPSupport.printPlatformSupport(...)` prints host specific details and not test specific details, so calling this in every single test would generate redundant output and would require update and future additions to every single test within the networking area. 
> 
> If this information isn't already captured in the jtreg failure handlers of the JDK, then I think we should enhance those failure handlers so that this same information gets collected just once when there is a test failure or a timeout. That I think should avoid all these test updates.

@jaikiran This is not just about test failures in IPv6 environments, but also that the test that pass are also correctly passing.
It will also assist in diagnosing failures in the CI pipelines. It is to assist is determining if anomalous behaviour is due to a dynamic configuration change in a test environment. It is to ensure that there is a consistent configuration and setup during the execution of the networking tests in an IPv6 only env.
Ask yourself why there are so many TCP4 connections rather than TCP4,6 connections in the failures associated with https://bugs.openjdk.org/browse/JDK-8273158 ?

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PR Comment: https://git.openjdk.org/jdk/pull/28420#issuecomment-3557926075