We present a novel 2-approximation algorithm for deploying stream graphs on multicore computers and a stream graph transformation that eliminates bottlenecks. The key technical insight is a data rate transfer model that enables the computation of a "closed form", i.e., the data rate transfer function of an actor depending on the arrival rate of the stream… (More)
We have devised an algorithm for minimal placement of bank selections in partitioned memory architectures. This algorithm is parameterizable for a chosen metric, such as speed, space, or energy. Bank switching is a technique that increases the code and data memory in microcontrollers without extending the address buses. Given a program in which variables… (More)
The computing landscape has shifted towards multicore architectures. To learn about software development, it is increasingly important for students to gain hands-on parallel programming experience in multicore environments. This experience will be significantly different from programming for uniprocessors, because it involves a profound understanding of how… (More)
It is well accepted that designing and analyzing concurrent software-components are tedious tasks. Assuring the quality of such software requires formal methods, which can statically detect deadlocks. This paper presents a symbolic data ow analysis framework for detecting deadlocks in Ada programs with tasks. The symbolic data ow framework is based on… (More)
In this paper we present data flow frameworks that are able to detect access anomalies in Ada multi-tasking programs. In particular , our approach finds all possible non-sequential accesses to shared non-protected variables. The algorithms employed are very efficient. Our approach is conservative and may find false positives.
The tree width of a graph G measures how close G is to being a tree or a series-parallel graph. Many well-known problems that are otherwise NP-complete can be solved efficiently if the underlying graph structure is restricted to one of fixed tree width. In this paper we prove that the tree width of goto-free Ada programs without labeled loops is ≤ 6. In… (More)
Energy-efficient implementation techniques for virtual machines (VMs) have received little attention yet: conventional wisdom claims that VMs have a diametrical effect on energy consumption and sensor network applications on VMs are therefore short-lived. In this paper we argue that bytecode interpretation is affordable for sensor networks if we synthesize… (More)
We present a generic symbolic analysis framework for imperative programming languages. Our framework is capable of computing all valid variable bindings of a program at given program points. This information is invaluable for domain-specific static program analyses such as memory leak detection, program parallelisation, and the detection of superfluous… (More)