multithreading - Is there an inituitive UML approach to depict threads

Question

I'm fond of using UML diagrams to describe my software. In the majority of cases the diagrams are for my own use and I use them for more involved pieces of code, interactions etc. where I'll benefit from being able to look back over them in the future.

One thing I've found myself doing a few different ways is diagramming threads. Threads by their nature tend to pop up in the more involved pieces of code and keeping track of them is often a primary purpose of my design documents.

In the past I've used a symbol in a sequence diagram to show the creation of a new thread but looking back at some diagrams doing that it's sometimes ambiguous between an object's lifetime - which sequence diagrams are for - and a thread's lifetime. Is there a better approach for incorporating threads into UML?

Answer 1

I managed to produce a diagram that makes sense to me at the time of drawing it. The basic premise is that I've overlaid grey boxes representing class instances with blue boxes representing thread lifetimes. The main thing it lets me keep track of is knowing which thread I will be executing on when I call certain methods.

No doubt there's better and more intuitive ways to do thread and class modeling. The measure of success for me is whether my own diagram still gives me the same level of understanding 6 months down the track.