@noisesmith Right, I forgot channel are mostly wrappers around BlockingQueues. But how would I control the pool of threads? If I use async/thread that always creates a new thread correct? Can I have it use a pool?

the simple way to do this is to always do a park on the result of your thread

that way you never have more threads than you have running go blocks, and it's pretty straightforward to control the number of go blocks running (eg. start N go-loops in a doseq, all reading from the same channel to get tasks)