Single Writer Principle
mechanical-sympathy.blogspot.com
mechanical-sympathy.blogspot.com
BTW, Java seems rather poor choice for a blog post about threading performance issues. It goes to great length trying to optimize stuff but it seems to me that switching programming language would be much more efficient and less time consuming.
That said, I agree that it is strange to see that they keep using Java for the main loop if they don't allow for garbage collection during operation. If they had used C for the main loop, the worker threads for the business logic could have been restarted on the fly.