Concurrency in general is hard. You'll find that most uses of concurrency in production systems is restricted to very specific patterns. This is probably not

Concurrency in general is hard. You'll find that most uses of concurrency in production systems is restricted to very specific patterns. This is probably not a conscious decision, rather it's just very likely that straying too far from very simple models of interaction between concurrent processes is actually just beyond the intellectual scope of most people. I do concurrency theory for a living, and concurrency primitives in Java still give me nightmares.