uml – Diagram about concurrency, flags, mutexes

In my studies I got taught a specific type of diagrams, containing the following:

  • Controllers
  • Flags
  • Mutexes
  • Queues
  • Pools

The goal of this type of diagram is to show which controllers communicate with which other controllers, and through which concurrency mechanisms.

Now I’m trying to explain certain mechanics to co-workers, which would be a lot easier if I could make a diagram like this. But I’ve completely forgotten the name of the diagram, which makes googling about it a lot harder.

What is this type of diagram called?