Handling Emergency Mode Switch for Component-Based Systems

Software reuse is deemed as an effective technique for managing the growing software complexity of large systems. Software complexity can also be reduced by partitioning the system behavior into different modes. Such a multi-mode system is able to dynamically change its behavior by switching between different modes. When a multi-mode system is developed by reusable software components, a crucial issue is how to achieve a seamless composition of multi-mode components and handle mode switch properly. This is the motivation for the Mode Switch Logic (MSL), supporting the development of component-based multi-mode systems by providing mechanisms for mode switch handling. In this paper, MSL is extended and adapted to systems with emergency triggering of mode switches that must be handled with minimal delay. We propose an Immediate Handling with Buffering (IHB) approach to enable the responsive handling of such an emergency event in the presence of other concurrent non-emergency mode switch events. We present a model checking based verification of IHB and illustrate its benefits by an example.