feat(runtime): implement thread affinity for runtime and dispatcher

[numinnex]

This PR adds an extra field to both Runtime and Dispatcher builder that allows user to set thread affinity.

[Berrysoft]

I suggest using core_affinity (or other equivalents) rather than nix, to support more platforms.

@George-Miao Do you think we need a feature gate for this PR?

[numinnex]

I think given that core_affinity is an extra dependency, feature gate wouldn't hurt. I just used nix because I am not big of a fan of slapping extra deps.

Will take a look into core_affinity guarantees about other platforms support.

[numinnex]

One more question tho, what behavior should we expose given an input that exceeds number of available CPUs ?

[numinnex]

I have pushed changes that replace nix with core_affinity, but the question from above still stands.

[George-Miao]

One more question tho, what behavior should we expose given an input that exceeds number of available CPUs ?

I think an error won't hurt.

[numinnex]

I have changed the implementation from using Vec to use HashSet, the vec implementation was wrong and convoluted.

[numinnex]

I don't understand why this test fails on MacOS and sadly I don't own one to test it locally :( but running those on my Linux setup works fine.

[Berrysoft]

It's not successful to get the error with last_os_error because the macOS method thread_policy_set doesn't set errno.

I think bind_to_cpu_set is OK to fail. We may just log the error (through compio_log::error!) and return silently.

[Berrysoft]

LGTM

[Berrysoft]

@AsakuraMizu help wanted: test_cmsg on Windows failed, but it should not be related to this PR.

[numinnex]

Maybe it's just a flaky test. Let me re-run those.

[numinnex]

Doesn't seem like that was the issue...

windows-sys got recently updated, maybe this is what causes this test to fail ?

But it was failing already, before merging the latest commit from master... So I doubt it.

[Berrysoft]

The test failure has been fixed in #449 and merged just now. Could you rebase this PR?

[Berrysoft]

I rebased it for you :)

[Berrysoft]

Oh no seems I didn't update the branch before rebase

[numinnex]

Thanks, I am away from my PC right now

[Berrysoft]

Thank you very much!