Chapter 21, Problem 21.1E

Explanation of Solution

Real-time systems using concurrent processes:

A real-time system is one where it has to respond within certain time limits.

Real time systems usually have to be implemented using concurrent processes due to the different types of stakeholder concern and the aspects supporting their implementation.

The different types of stakeholder concern and the aspects supporting their implementation are:

• Functional concerns are related to the specific functionality to be included in a system. The base system should implement core functionality and extensions implemented as aspects that can implement secondary functionality.
• Quality of service concern is related to non-functional behaviour of the system and aspects may be used to implement cross-cutting functionality such as cache which helps to meet these requirements.
•  Policy concerns are related to overall policies that govern the use of system and by representing cross-cutting concerns as aspects which can be implemented.
• System concerns are related to attributes of the system as a whole and aspects may be used to implement monitoring that checks system attributes.
• Organizational concerns are related to organizational goals and priorities, aspects have limited usefulness in implementing these types of concerns.