UML Modeling Techniques > Concurrency modeling > Concurrency primitives
  
Concurrency primitives
You can add the following concurrency primitives to your Concurrency Model:
Pool
Mailbox
Semaphore
Channel
Synchronizer
Monitor
Event flag group
You attach an event or operation message to a link with a concurrency primitive, but to attach an operation message the primitive must first be associated with a class.
Use the appropriate icon on the Concurrency Diagram toolbar to add a concurrency primitive to the diagram, or you can drag a concurrency primitive from the dictionary.
When you have added a concurrency primitive, you can change it through the concurrency primitive's Property pages, including linking it to a class.