[chadaustin]

I'm sorry, I had a whole section on amortized allocation in a draft version of the post but I deleted it, thinking it was tangential. You're not the first person to ask: https://www.reddit.com/r/rust/comments/1gbqy6c/comment/ltonq...

And my response: https://www.reddit.com/r/rust/comments/1gbqy6c/comment/ltpv0...

One typical approach is double-buffering the allocation but it doesn't work here because you need to pull out the waker list to call `wake()` outside of the mutex. You could try to put the allocation back, but you have to acquire the lock again.

I had an implementation that kept a lock-free waker pool around https://docs.rs/wakerpool/latest/wakerpool/ but now you're paying for atomics too, and it felt like this was all a workaround for a deficiency in the language.

Intrusive lists are the "correct" data structure, so I kept pushing.