This dissertation presents techniques to achieve predictable execution of coarse-grained software components and for preservation of temporal properties of components during their integration and reuse. The dissertation presents a novel concept runnable virtual node (RVN) which interaction with the environment is bounded both by a functional and a temporal interface, and the validity of its internal temporal behaviour is preserved when integrated with other components or when reused in a new environment. The realization of RVN exploits techniques for hierarchical scheduling to achieve temporal isolation, and the principles from component-based software-engineering to achieve functional isolation. The proof-of-concept case studies executed on a micro-controller demonstrate the preserving of real-time properties within software components for predictable integration and reusability in a new environment, in both hierarchical scheduling and RVN contexts. Further, a multi-resource server (MRS) is proposed and implemented to enable predictable execution when composing multiple real-time components on a COTS multicore platform. MRS uses resource reservation for both CPU-bandwidth and memory-bus bandwidth to bound the interferences between tasks running on the same core, as well as, between tasks running on different cores. The later could, without MRS, interfere with each other due to contention on a shared memory-bus and memory. The results indicated that MRS can be used to "encapsulate" legacy systems and to give them enough resources to fulfill their purpose. In the dissertation, the compositional schedulability analysis for MRS is also provided and an experimental study is performed to bring insight on the correlation between the server budgets. We believe that the proposed approaches enable a faster software integration and support legacy reuse and that this work transcend the boundaries of software engineering and real-time systems. / PPMSched / PROGRESS

This thesis introduces a visual composition approach for JavaBeans components, in compliance with the Component Oriented Software Engineering (COSE) process. The graphical modeling tool, COSECASE, is enhanced with the ability to build a system by integrating domain-specific components. Such integration is implemented by defining connection points and interaction details between components. The event model of the JavaBeans architecture is also added to the capabilities.

Owing to advancements in component re-use technology, component-based software development (CBSD) has come a long way in developing complex commercial software systems while reducing software development time and cost. However, assembling distributed resource-constrained and safety-critical systems using current assembly techniques is a challenge. Within complex systems when there are numerous ways to assemble the components unless the software architecture clearly defines how the components should be composed, determining the correct assembly that satisfies the system assembly constraints is difficult. Component technologies like CORBA and .NET do a very good job of integrating components, but they do not automate component assembly; it is the system developer's responsibility to ensure thatthe components are assembled correctly. In this thesis, we first define a component-based system assembly (CBSA) technique called "Constrained Component Assembly Technique" (CCAT), which is useful when the system has complex assembly constraints and the system architecture specifies component composition as assembly constraints. The technique poses the question: Does there exist a way of assembling the components that satisfies all the connection, performance, reliability, and safety constraints of the system, while optimizing the objective constraint? To implement CCAT, we present a powerful framework called "CoBaSA". The CoBaSA framework includes an expressive language for declaratively describing component functional and extra-functional properties, component interfaces, system-level and component-level connection, performance, reliability, safety, and optimization constraints. To perform CBSA, we first write a program (in the CoBaSA language) describing the CBSA specifications and constraints, and then an interpreter translates the CBSA program into a satisfiability and optimization problem. Solving the generated satisfiability and optimization problem is equivalent to answering the question posed by CCAT. If a satisfiable solution is found, we deduce that the system can be assembled without violating any constraints. Since CCAT and CoBaSA provide a mechanism for assembling systems that have complex assembly constraints, they can be utilized in several industries like the avionics industry. We demonstrate the merits of CoBaSA by assembling an actual avionic system that could be used on-board a Boeing aircraft. The empirical evaluation shows that our approach is promising and can scale to handle complex industrial problems.