RFR: 8302659: Modernize Windows native code for NetworkInterface [v3]

[Alan Bateman]

On Wed, 22 Feb 2023 17:40:31 GMT, Rich DiCroce <duke at openjdk.org> wrote:

>> Improves performance and correctness, as discussed on the net-dev mailing list.
>
> Rich DiCroce has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - Forgot to add file
>  - Resolve review comments

Overall I think this is a very contribution. It's good to modernize this code and remove the cruft that dates from before many of the new APIs were added.

I suspect we will need a release document any behaviour changes that may be observed when upgrading the JDK. In particular, the network interface names will look different. The synthesized names were names like "lo" and "eth0" whereas the new names come from Windows (names like "lookup_0" and "ethernet_0"). I haven't found tools that show the names that ConvertInterfaceLuidToNameW returns but if there are then the RN could mention it. On other platforms, it would be was easy for configuration to name the interface to be used for multicasting, it doesn't seem easy to do the same on Windows and application might have to resort to configuration by IP address.

I'm not too concerned that interfaces without IP addresses are enumerated. They aren't useful for multicasting applications but maybe they are useful for informational purposes, e.g. programs that collect system environment. I'm also not too concern about the ordering of the IP addresses. I'll defer to @djelinski on whether some JDK tests or test infra needs to be updated in advance to ensure that tests that choose interfaces will continue to work.

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PR: https://git.openjdk.org/jdk/pull/12593