Boosting Ruby Ractor Performance: Tackling the `object_id` Bottleneck

Ruby's Ractor concurrency model suffers from performance limitations due to global locks. This post dives deep into a performance bottleneck caused by the `object_id` method, stemming from historical design choices and improvements to garbage collection. By optimizing `object_id`'s implementation, storing it directly within objects instead of using a global hash table lookup, the author significantly improves Ractor performance, resulting in a two-fold speed increase in JSON benchmarks. While challenges remain, such as handling special object types, this work represents a crucial step towards making Ractors truly parallel.