We strive to address the challenge of constructing a modeling language to write software which can take advantage of recent hardware developments (multicore, cloud) without compromising in its... Show moreWe strive to address the challenge of constructing a modeling language to write software which can take advantage of recent hardware developments (multicore, cloud) without compromising in its abstraction levels. Our language is based on top of the Abstract Behavioral Specification (ABS), which is an executable modeling language with a focus on cooperative-multitasking concurrency. We translate programs written in ABS to Haskell, an established functional programming language, since Haskell supports both cooperative concurrency in the form of coroutines, and multicore parallelism through lightweight threads of execution. Further, we formally prove the correctness as well as the resource-consumption preservation of the translation of a subset of our language to Haskell.To enable software models take control of their computing resources, we extend our language with certain constructs that abstract over the hardware. This resource-aware language extension is packaged in a tool-suite for human-in-the-loop simulation of Cloud services; such a live simulation can be used for training DevOps to the cloud environment of IT companies.Finally, we provide an implementation of distributed communication to the Cloud infrastructure, so that software models written in ABS can be executed as distributed applications, which can programmatically monitor and control their own Cloud deployment. Show less
The core contributions of this thesis target the intersection of object orientation, actor model, and concurrency. We choose Java as the main target programming language and as one of the... Show more The core contributions of this thesis target the intersection of object orientation, actor model, and concurrency. We choose Java as the main target programming language and as one of the mainstream object-oriented languages. We formalize a subset of Java and its concurrency API to facilitate formal verification and reasoning about it. We create an abstract mapping from a concurrent-object modeling language, ABS, to the programming semantics of concurrent Java. We provide the formal semantics of the mapping and runtime properties of the concurrency layer including deadlines and scheduling policies. We provide an implementation of the ABS concurrency layer as a Java API library and framework utilizing the latest language additions in Java 8. Show less
This work contributes to the field of coordination, in particular to Reo, by improving existing approaches to execute synchronisation models in three major ways. First, this work supports decoupled... Show moreThis work contributes to the field of coordination, in particular to Reo, by improving existing approaches to execute synchronisation models in three major ways. First, this work supports decoupled execution and lightweight reconfiguration. We developed a prototype Dreams engine to test our distributed protocol, using an actor library for the Scala language. Reconfiguration of a small part of the system is independent of the execution or behaviour of unrelated parts of the same system. Second, Dreams outperforms previous Reo engines by using constraint satisfaction techniques. In each round of the execution of the Dreams framework, descriptions of the behaviour of all building blocks are combined and a coordination pattern for the current round is chosen using constraint satisfaction techniques. This approach requiring less time than previous attempts that collect all patterns before selecting one. Third, our work improves scalability by identifying synchronous regions. We statically discover regions of the coordination layer that can execute independently, thus achieving a truly decoupled execution of connectors. Consequently, the constraint problem representing the behaviour at each round is smaller and more easily solved. Show less
The software today is distributed over several processing units. At a large scale this may span over the globe via the internet, or at the micro scale, a software may be distributed on several... Show moreThe software today is distributed over several processing units. At a large scale this may span over the globe via the internet, or at the micro scale, a software may be distributed on several small processing units embedded in one device. Real-time distributed software and services need to be timely and respond to the requests in time. The Quality of Service of real time software depends on how it schedules its tasks to be executed. The state of the art in programming distributed software, like in Java, the scheduling is left to the underlying infrastructure and in particular the operating system, which is not anymore in the control of the applications. In this thesis, we introduce a software paradigm based on object orientation in which real-time concurrent objects are enabled to specify their own scheduling strategy. We developed high-level formal models for specifying distributed software based on this paradigm in which the quality of service requirements are specified as deadlines on performing and finishing tasks. At this level we developed techniques to verify that these requirements are satisfied. This research has opened the way to a new approach to modeling and analysis of a range of applications such as continuous planning in the context of logistics software in a dynamic environment as well as developing software for multi-core systems. Industrial companies (DEAL services) and research centers (the Uppsala Programming for Multicore Architectures Resrearch Center UPMARC) have already shown interest in the results of this thesis. Show less
