I can assure you that I did not spend a full semester making graphs. I know it's not the first deterministic concurrency model. Thank you for making me realize that the concurrency model described can be modeled using CSP. That's neat, considering all the analysis tools available for it. Determinism is not enough, however. The space of all thread state combinations need to be reined in, not least because while deadlocks & co. can be found using automated tools, subtler errors can't. Additionally, threads compete for resources, and you need to account for hidden sources of indeterminism like that one. Two logically independent threads that can be modelled and trivially shown to not interfere with each other will definitely interfere with each other on a single-core system.

I realize that this is an unusually strict approach. I'm also terribly embarrassed if there's something I haven't considered.