Inspired by reading go-cache and reading about core.async I was interested how well sending functions over a channel can work, here is the quick hacky result.
Clojure with its access to a very concise way to construct functions lends itself very nicely to the idea of using CSP with first class functions as messages passed over a channel.
(let [c (chan)] (>!! c #(zero? %)))
Given that a channel is only consumed by one thread, this provides an interesting way to sync on a data structure without the need for explicit locking as the channel with by itself serialize the operations. This could be quite performant depending on the consumer as multiple operations could be pipelined for example by polling the channel for a batch of operations to be dispatched to different workers.
This is mainly an idea taken from playing with go-lang and implemented in clojure, for access to a basic data structure like a map, even so it can now be a transient map, the built in transactions will provide much better performance.