Research And Implementation Of A COP-Based Approach To Control Software System Reliability

With the continuous development of software technology, control software system is widely used in home, office, medical and other fields, while the software reliability requirements are also increasing. Context has become a central notion in designing and developing control software, for this feature of control software development, context oriented programming provide good support for it. However, requirements to the control software may be enhanced with the changes of software context environment. Context oriented programming makes it possible to change the software behavior at specified context environment by defining new behavior variation. However, there are some inadequacies of such traditional approach as followed:1) Behavior variation definition conflict problem. The new behavior variations defined by reliability enhancement component may conflict with the existing behavior variation. Operations of different behavior variations to same shared resources may lead to inconsistency of the resources’ states, so there are conflict relations between such behavior variations definitions. For instance, two behavior variations definition in vehicle control software, one makes the motor forward while another makes it stop; such two behavior variations are conflict with each other. Conflict relation need to be detected to coordinate their concurrent execution. However, there is no syntax element in current context oriented programming languages, which is used to detect conflict relations.2) Problem of behavior variation concurrency. If new behavior variations conflict with the existing behavior variations, it’s necessary to coordinate their concurrent execution, including execution sequence and execution interruption. Current context oriented programming languages do not have explicit and convenient support to such problem. Context oriented programming languages use the mechanisms provided by host-language to manage behavior variation’s concurrency, for example, Java multi-thread mechanism. While this method is always useful but not straightforward and efficient enough. What’s more, the users need to provide corresponding source codes, while this makes user cannot concentrate to design the features of reliability enhancement.In order to solve the problems described above and provide good support for control software development and its reliability expansion, we reviewed existing research results of context oriented programming, and proposed a new framework to the reliable control software development and reliability expansion. The main work is summarized as follows:1) We designed a framework and implemented prototype system for reliable control software development. The framework imported behavior variation conflict detection approach to EventCJ, and provided the management mechanism of behavior variation concurrent execution to solve the lack in EventCJ. A prototype system was developed based the framework. It used the MaC tool to monitor and check the context information at software execution.2) We proposed approaches to detect and process the conflict in behavior variation definition. In order to solve the behavior variation definition constraints lack problem, we defined conflict relation between behavior variations and designed a conflict detection approach, we also proposed an approach which could generate maximum conflict set from conflict detection result.3) We introduced a coordination mechanism to manage the behavior variation concurrent execution. According to the conflict relation and relative priority of behavior variation, the mechanism was used to manage the execution order. We also provide an approach to maintain the software’s concurrency based on the interruption and the context save and restore mechanism.