Using C#, I have been doing multithreaded development for about 5 years, and consider myself quite proficient (I wrote my own lock-free queue and task parallel framework before Microsoft made TPF).
However, I find it incredibly difficult to find information on practical multithreaded system design patterns anywhere. There are some good resources on low-level algorithms and collections, but not much on system design.
So to the question, anyone know where this information can be found?