Comment by zbentley

I have some questions and requests for clarification/suspicious behavior I noticed after reviewing the results and the benchmark code, specifically:

- If slotted attribute reads and regular attribute reads are the same latency, I suspect that either the regular class may not have enough "bells on" (inheritance/metaprogramming/dunder overriding/etc) to defeat simple optimizations that cache away attribute access, thus making it equivalent in speed to slotted classes. I know that over time slotting will become less of a performance boost, but--and this is just my intuition and I may well be wrong--I don't get the impression that we're there yet.

- Similarly "read from @property" seems suspiciously fast to me. Even with descriptor-protocol awareness in the class lookup cache, the overhead of calling a method seems surprisingly similar to the overhead of accessing a field. That might be explained away by the fact that property descriptors' "get" methods are guaranteed to be the simplest and easiest to optimize of all call forms (bound method, guaranteed to never be any parameters), and so the overhead of setting up the stack/frame/args may be substantially minimized...but that would only be true if the property's method body was "return 1" or something very fast. The properties tested for these benchmarks, though, are looking up other fields on the class, so I'd expect them to be a lot slower than field access, not just a little slower (https://news.ycombinator.com/item?id=46056895) and not representative. To benchmark "time it takes for the event loop to spin once and produce a result"/the python equivalent of process.nextTick, it'd be better to use low-level loop methods like "call_soon" or defer completion to a Task and await that.