How to model "OR" in activity diagram

[RainerQ]

What would be the correct way to model
-- ServiceBase.Run(new MyService()); --
in a UML2.1 activity diagram:

First "action" would be to instantiate "MyService" but what then? There is a variaty of possible flows to reach the activity final:
- Service.OnStart , Service.OnStop
- Service.OnStart, Service.OnShutdown
- Service OnStop
- Serivice OnSutdown
- ......

I think the "receive signal" with follow up actions are part of the solution, but how to I model the "OR" possibilities form the "intatniate" action on?

Thanks for hints and help.

Regards
Rainer

[philchudley]

How about a decision with three outgoing flows?