Independent AND-parallel implementation of narrowing

We present a parallel graph narrowing machine, which is used to implement a functional logic language on a shared memory multiprocessor. It is an extensión of an abstract machine for a purely functional language. The result is a programmed graph reduction machine which integrates the mechanisms of unification, backtracking, and independent and-parallelism. In the machine, the subexpressions of an expression can run in parallel. In the case of backtracking, the structure of an expression is used to avoid the reevaluation of subexpressions as far as possible. Deterministic computations are detected. Their results are maintained and need not be reevaluated after backtracking

A Model-Driven Cross-Platform App Development Process for Heterogeneous Device Classes

App development has gained importance since the advent of smartphones to enable the ubiquitous access to information. Until now, multi- or cross-platform approaches are usually limited to different platforms for smartphones and tablets. With the recent trend towards app-enabled mobile devices, a plethora of heterogeneous devices such as smartwatches and smart TVs continues to emerge. For app developers, the situation resembles the early days of smartphones but worsened by the widely differing hardware, platform capabilities, and usage patterns. In order to tackle the identified challenges of app development beyond the boundaries of individual device classes, a systematic process built on the model-driven paradigm is presented. In addition, we demonstrate its applicability using the MAML framework to create interoperable business apps for both smartphones and smartwatches from a common, platform-independent model

The Integration of Task and Data Parallel Skeletons

We describe a skeletal parallel programming library which integrates task and data parallel constructs within an API for C++. Traditional skeletal requirements for higher orderness and polymorphism are achieved through exploitation of operator overloading and templates, while the underlying parallelism is provided by MPI. We present a case study describing two algorithms for the travelling salesman problem

Muggl: The Muenster Generator of Glass-box Test Cases

Testing is a task that requires much effort, yet it is essential for developing software. Automated test case generation (TCG) promises to relieve humans of manual work. We introduce Muggl (the Muenster generator of glass-box test cases), which is developed at our institute. Muggl generates test cases for Java bytecode. It symbolically executes code and uses constraint solving techniques. While papers on Muggl have already been published, no comprehensive introduction of the tool exist. This working paper fills this gap

Achieving Business Practicability of Model-Driven Cross-Platform Apps

Due to the incompatibility of mobile device platforms such as Android and iOS, apps have to be developed separately for each target platform. Cross-platform development approaches based on Web technology have significantly improved over the last years. However, since they do not lead to native apps, these frameworks are not feasible for all kinds of business apps. Moreover, the way apps are developed is cumbersome. Advanced cross-platform approaches such as MD2, which is based on model-driven development (MDSD) techniques, are a much more powerful yet less mature choice. We discuss business implications of MDSD for apps and introduce MD2 as our proposed solution to fulfill typical requirements. Moreover, we highlight a business-oriented enhancement that further increases MD2's business practicability. We generalize our findings and sketch the path towards more versatile MDSD of apps

A Symbolic Java Virtual Machine for Test Case Generation

Quality management is becoming a more and more important part of the software development process. As software testing is currently understood as the core function of the quality managment, developers start using software testing tools to facilitate their work. However most existing tools just manage given sets of test cases and check them against pre-defined testing criteria. The necessary test case discovery is usually up to user, who has to generate the test cases in an ad-hoc approach with only minimal support from the software. GlassTT, the tool we present in this paper, faces this problem by creating the needed test cases for a given criterion for a Java class file. It uses a symbolic Java virtual machine to generate constraints representing the conditions for the control flow under consideration. The system can employ a parameterizeable test criterion such as data-flow coverage. The constraint solvers embedded in the tool are capable of solving linear and non-linear constraints, which is sufficient for almost all constraints encountered in the execution of Java programs. They are encapsulated in an incremental constraint solver manager, which dynamically chooses an appropriate constraint solver and enables the efficient communication between constraint solvers and symbolical virtual machine

The Münster Skeleton Library ‚Muesli‘:A Comprehensive Overview

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