Diagram type for visualising threads and synchronization among them

The other day I was writing a sequence diagram on the blackboard, which is really good for visualising interaction between different components. However I realised that we had several different threads interacting (synchr开发者_Go百科onizing and signalling), and I had no good way to visualise that.

Do you know a diagram type that is good for visualising interactions between different threads?

I am not looking for a drawing program or anything, just a diagram type I can memorize and use on the blackboard.

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Have you looked at Activity Diagrams? They have specific syntax for showing parallel activities, including messaging and synchronisation. You can use swimlanes (or partitions) to show different threads if required.

hth.