Performance of NetworkInterface methods on Windows

[DiCroce, Richard]

Okay, so based on the various replies I've gotten, it sounds like we want a patch that:

1) Completely rewrites the native code using newer APIs, and gets rid of the dual implementations that exist today (per Daniel Jelinski)
2) Gets rid of the homebrew interface naming scheme in favor of what the Windows API returns (per Alan Bateman)

Do we care about backwards compatibility for NetworkInterface#getByIndex() and getByName()? Based on my experiments, I don't think the indexes will actually change, but I can't 100% guarantee that. The names will definitely change though, per #2 above. How do we want to handle that? Do we just put something in the release notes saying there's a change that's not backwards-compatible? Or do we want to do a fallback to the existing naming scheme if the Windows API doesn't recognize a name? Or something else entirely, like a system property to toggle the behavior?


Rich DiCroce
Senior Advanced Solutions Architect

Scientific Games


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-----Original Message-----
From: Daniel Fuchs <daniel.fuchs at oracle.com> 
Sent: Wednesday, February 8, 2023 7:44 AM
To: DiCroce, Richard <Rich.DiCroce at scientificgames.com>; net-dev at openjdk.org
Subject: Re: Performance of NetworkInterface methods on Windows

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Hi Richard,

On 07/02/2023 21:04, DiCroce, Richard wrote:
> Hi Daniel,
> I'm not proposing to add any caching, or change anything about the Java side of NetworkInterface, for exactly the reasons you state. This first patch is purely a change to the native code to make it so that getAll only calls the Windows API once instead of N + 1 times.

Oh, OK - good to hear. That sounds interesting then, sorry for assuming!
:-)

> createNetworkInterface actually already had parameters for passing the previously fetched list of interfaces. getAll just doesn't currently do that.
>
> This would probably be easier to discuss if you could actually see the changes I'm proposing. Should I attach a patch to an email, or is there a better way of doing that?

Jaikiran replied with a good suggestion for that. But please take into account Daniel Jelinski's comments first.

best regards,

-- daniel

>
> Thanks,
>
> Rich DiCroce