It uses also tracing GC to handle RC loops. I guess doing it this way allows to have mostly deterministic collection (that is then just an implementation featu

It uses also tracing GC to handle RC loops. I guess doing it this way allows to have mostly deterministic collection (that is then just an implementation feature, not language semantics) while needing the actual tracing GC to not be that efficient, as it presumably needs to be executed less rarely.