Specifying Contractual Use, Protocols and Quality Attributes for Software Components

We discuss the specification of signatures, protocols (behaviour) and quality of service within software component specification frameworks. In particular we focus on (a) contractually used components, (b) the specification of components with variable contracts and interfaces, and (c) of quality of service. Interface descriptions including these aspects allow powerful static interoperability checks. Unfortunately, the specification of constant component interfaces hinders the specification of quality attributes and impedes automated component adaptation. This is because, especially quality attributes heavily depend on the components context. To enable the specification of quality attributes, we demonstrate the inclusion of parameterised contracts within a component specification framework. These parameterised contracts compute adapted, context-dependent component interfaces (including protocols and quality attributes). This allows to take context dependencies into account while allowing powerful static interoperability checks.