snoyberg/conduit — comment on commit 369c2ff6966446a985b0d7d072150c515e86da13
File:  line 0
By snoyberg:

I was curious to see what the actual performance implications would be of making this change, so I put together a Gist:

https://gist.github.com/1628517

The results are a bit shocking: not only is `modifyIORef` twice as fast as `atomicModifyIORef`, but `modifyMVar` is even faster than it! Do you see anything wrong with the test? If not, I think this needs to be mentioned on the cafe.

So yes, I agree that we can get rid of `atomicModifyIORef`. I liked the concept that some operations would still be atomic, but it's actually a bad idea to give a half-guarantee of atomicity anyway.