Integrating aspect-orientation and structural annotations to support adaptive middleware

To anticipate or not to anticipate — that is the question, re-garding adaptive middleware in the area of ubiquitous com-puting. Anticipation can guarantee that both the adapted and the adapting component work together safely, but it lim-its the scenario space to some predictable well-known cases. This holds even more when statically typed languages are used, as we assume here. A second problem is a seman-tic gap between the business logic that triggers the adapta-tion and the technological demands of the adaptation that must be solved on the implementation level. We discuss current approaches and describe a new approach combining aspect-oriented programming with structural metadata to cope with both problems. An example illustrates how our approach will work in practice

A Statically Typed Logic Context Query Language With Parametric Polymorphism and Subtyping

The objective of this thesis is programming language support for context-sensitive program adaptations. Driven by the requirements for context-aware adaptation languages, a statically typed Object-oriented logic Context Query Language  (OCQL) was developed, which is suitable for integration with adaptation languages based on the Java type system. The ambient information considered in context-aware applications often originates from several, potentially distributed sources. OCQL employs the Semantic Web-language RDF Schema to structure and combine distributed context information. OCQL offers parametric polymorphism, subtyping, and a fixed set of meta-predicates. Its type system is based on mode analysis and a subset of Java Generics. For this reason a mode-inference approach for normal logic programs that considers variable aliasing and sharing was extended to cover all-solution predicates. OCQL is complemented by a service-oriented context-management infrastructure that supports the integration of OCQL with runtime adaptation approaches. The applicability of the language and its infrastructure were demonstrated with the context-aware aspect language CSLogicAJ. CSLogicAJ aspects encapsulate context-aware behavior and define in which contextual situation and program execution state the behavior is woven into the running program. The thesis concludes with a case study analyzing how runtime adaptation of mobile applications can be supported by pure object-, service- and context-aware aspect-orientation. Our study has shown that CSLogicAJ can improve the modularization of context-aware applications and reduce anticipation of runtime adaptations when compared to other approaches

Automatische Performanzoptimierung paralleler Architekturen

Die Parallelisierung von Programmen und deren Optimierung stellen Software-Entwickler vor große Herausforderungen. Diese Arbeit befasst sich daher mit Problemstellungen im Bereich der automatischen Performanzoptimierung (Auto-Tuning) paralleler Architekturen. Hierzu wird ein Verfahren für den Entwurf paralleler optimierbarer Architekturen vorgestellt; das Konzept eines suchbasierten Auto-Tuners rundet die Arbeit ab. Die Evaluationsergebnisse erweisen sich als äußerst vielversprechend