Remove ConcurrentDictionary lookups from Unix socket event loop

[MihaZupan]

Running a bunch of different scenarios, this appears to be a slight improvement (<= 1%) on average, but that's below the run-to-run variance for these benchmarks.

@sebastienros is something like scenarios/platform.benchmarks.yml --scenario plaintext --profile aspnet-gold-lin reasonable for ASP.NET these days?

cc: @tmds @benaadams

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[MihaZupan]

/azp run runtime-libraries-coreclr outerloop

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[sebastienros]

@MihaZupan

scenarios/platform.benchmarks.yml --scenario plaintext --profile aspnet-gold-lin

When working on overall perf gains we should use the gold machines now, correct. I would suggest to use JsonPlatform however for generic changes. Plaintext can be useful if you want to reduce the impact of networking (pipelining). I don't think we want that here.

[liveans]

Thanks for the offline chat about it!

[MihaZupan]

The most consistent improvement I see is for platform json on citrine of just over 2%.
Other benchmarks are much closer to noise/within 1% diffs.

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[MihaZupan]

I switched the implementation from the non-standard use of "leaked" GCHandles to simply use an index into a global table as the data passed to epoll.

Running more benchmarks, this is showing a consistent ~3 % RPS improvement for platform Json on citrine.

[sebastienros]

Running more benchmarks, this is showing a consistent ~3 % RPS improvement for platform Json on citrine.

There were recent changes in the runtime that triggered a similar improvement on JSON benchmark, please make sure you are only comparing your changes, ideally by rebasing on main or using the latest with your own builds of the changed and unchanged dlls.

[MihaZupan]

I did, just manually replacing Sockets dlls

[antonfirsov]

LGTM