Question regarding concurrently running a service

Unless you are using the Threading library, your code always runs in the main thread (libraries code can run in different threads). This means that there could only be a single event running at any time.

Thanks Erel,
I did not want to go into threading at this stage since i am still a newbie and i think it might overcomplicate the solution

I solved the problem in this way:
-I have Service A that starts Service B after receiving event "X" (lets say event is SMS received)
- Service A also has a global boolean : FLAG
--- Service B has a timer in it and does Task B

SOLUTION: Check if Timer.Enabled = true - then wait till Timer.Enabled = false
This way i am making sure that the timer always runs...

---- Service B then changes status of FLAG to false
-------If Flag is false - service B does nothing

Now no error is caused with concurrent events - since i am waiting for the events to be processed sequentially.
My app is not mission critical - so this solution seems to work ok. Also my timer is only 5 seconds so not really an issue...

Thank you!