Use fastbarriers

[ibraheemdev]

Implements the light/heavy barriers using membarrier.

[jonhoo]

Can you rebase onto master?

[codecov-commenter]

Codecov Report

Merging #25 (ed27d5b) into main (ba8ffcc) will not change coverage. The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main      #25   +/-   ##
=======================================
  Coverage   84.08%   84.08%           
=======================================
  Files           8        9    +1     
  Lines         817      817           
=======================================
  Hits          687      687           
  Misses        130      130           

Impacted Files	Coverage Δ
src/lib.rs	30.37% <ø> (-3.36%)	:arrow_down:
src/record.rs	100.00% <ø> (ø)
src/domain.rs	85.71% <100.00%> (ø)
src/hazard.rs	73.43% <100.00%> (ø)
src/sync.rs	100.00% <100.00%> (ø)

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[jonhoo]

Oh, I just pushed a change that re-adds the Miri isolation to make debugging easier. But I suppose we may have to re-disable it for this :thinking:

[ibraheemdev]

Hmmm, miri doesn't support the membarrier syscall. I guess it should just use a regular fence under cfg(miri) then?

[jonhoo]

Ah, yes, let's do that instead! I'd rather keep Miri's isolation if we can :+1:

[jonhoo]

It's arguably something that could be fixed in membarriers actually — consider Miri a platform that doesn't support other barrier types.

[ibraheemdev]

Error: | = note: the thumbv7m-none-eabi target may not support the standard library = note: std is required by winapi because it does not declare #![no_std]

This is odd, because winapi is no_std :thinking:

[ibraheemdev]

It seems membarrier is using an older winapi interface that presumably required std: https://github.com/jeehoonkang/membarrier-rs/issues/21. membarrier seems to be unmaintained... maybe we should just inline it? cc @jeehoonkang

[jeehoonkang]

Hi! Thanks for your interest in the membarrier crate. I think I don't have enough bandwidth to address this issue myself, but I'm happy to accept PRs.

[Pesky01]

This is an old thread, but I did submit a PR for the membarrier crate to update the windows api used. We can wait to see if it gets merged, or we can do what DataDog did and just have a membarrier.rs with the relevant code since it's pretty small and I believe the licenses are compatible.

Edit: PR has been merged into master! Is there anything stopping this from getting merged/is it worth merging?

[jonhoo]

That's awesome! I'd still like to see this land, and I believe the change is pretty much good as-is and would just need a rebase + an update to the version number listed in Cargo.toml to capture that change. @ibraheemdev you up for a quick touch-up of this PR?