[stcredzero]

While I agree that generational GC can perform spectacularly well, what you're describing is close to the case it's optimized for, not close to its worst case

Here's the thing: Most of the rest of the app was rather close to the case it's optimized for.

I don't know what you mean by "something like LINT but for the runtime reference graph."

Something that tells you that you've created a reference graph with a cycle, you have a memory leak, or that you're using references in some other stupid or suboptimal way. I'm not even sure if there's a way to automatically detect anything like the last category, though the first two are certainly detectable. Basically, you take most of the infrastructure of GC, and you just turn it into a runtime advisor to warn devs and testers of mistakes.

[kragen]

Great Circle commercialized the Boehm collector back in the 1990s, and I seem to recall that most of their customers were using it to tell them when they had a memory leak or reused freed memory, not to remove the need for reference counting altogether. But it didn't tell you about cyclic references, unless they resulted in a memory leak.