1. Scenario Based Resolution of Aspect Interactions with Aspect Interaction Charts Shubhanan Bakre, Tzilla Elrad Illinois Institute of Technology

2. Overview Goals Background – Live Sequence Charts (LSC) and Play Engine Motivating example Aspect Interaction Charts Based on LSC and the Play Engine

3. Goals Modular specification for aspect interactions Executable specification Tools for ease of specification & refinement

4. Goals … Synchronization Data/State sharing Access control AspectAAspectB precedes AspectAAspectB AspectA AspectB AspectC Aspect D

5. Live Sequence Charts & the Play Engine Pre chart, main chart, messages, conditions, sub charts … Play Engine - Play in, play out UML Sequence diagrams Vs LSC Aspect scenarios using LSC

6. Motivating Example The user opens the flap of the cell phone. The system checks if enough battery power is available. If the keypad is locked, the display shows the unlock screen. The system communicates with the base station in order to establish a network in case a call is being received. Depending upon the context, speakers/mic or both are turned on. The display is updated according to the context.

7. Open Flap – Display Update

8. Open Flap – Power Control

9. Open Flap – Display Update with Power Control

10. Open Flap – Display Update with Security

11. Open Flap – Network Connection Management

12. Open Flap – Device Control

13. Open Flap – What We Want Power ControlDisplay Update Security is ON Network Connection Manager Device ControlDisplay Update Security

14. Aspect Interaction Charts (AIC) Higher level abstraction Adopts LSC constructs like pre chart, main chart, message, condition, forbidden section & elements. LSC instances ‘before’ message event LSC Instance

15. Open Flap – Aspect Interaction Chart Solution

16. AIC – Foreseeable Benefits Modularizes aspect interactions Improves modularity of the aspect specification LSC & Play Engine enables Tool support for specification Execution of the model Possibility of translating model into platform specific model Rich language constructs

17. AIC – Challenges Adoption under UML standard Language constructs for specifying state sharing between aspects Language constructs for specifying access control for aspects at join points

18. References – LSC & Play Engine D. Harel and R. Marelly. Come, Let’s Play: Scenario-Based Programming Using LSC’s and the Play-Engine. Springer-Verlag, 2003.

19. Questions?