Abstract
The widespread use of multi-CPU computers is challenging programming languages, which need to adapt to be able to express potential parallelism at the language level. In this paper we propose a new model for fine grained parallelism in Ada, putting forward a syntax based on aspects, and the corresponding semantics to integrate this model with the existing Ada tasking capabilities. We also propose a standard interface and show how it can be extended by the user or library writers to implement their own parallelization strategies. © 2013 Springer-Verlag.

Abstract

Abstract
The second session on the topic of Multiprocessor Issues reviewed and evaluated the efficacy of the Ada 2012 support in the area of multiprocessor resource control. Andy Wellings, the Chair presented a proposal of an API that allowed controlling and extending the queue locks, and implementing the access control protocols. In the second part of the session, Miguel Pinho started by presenting an overview of Transactional Memory (TM), providing a quick overview of how in this approach atomic sections are executed concurrently and speculatively, in isolation. In the third topic of the session, the Chair started by providing an overview of the Reference Manual wordings concerning the access and control protocols for Protected Objects, noting that both the RM and the Annotated Reference Manual (ARM) do not fully define the access protocol for a protected object on a multiprocessor system. Finally, in the last topic (parallel barriers in Protected Objects), the workshop concluded that this would be a good mechanism to have, but that a suitable approach needs further investigation.

Abstract

Abstract
Designing cost-efficient multi-core real-time systems requires efficient techniques to allocate applications to cores while satisfying their timing constraints. However, existing approaches typically allocate using a First-Fit algorithm, which does not consider the execution time and potential parallelism of paths in the applications, resulting in over-dimensioned systems. This work addresses this problem by proposing a new heuristic algorithm, Critical-Path-First, for the allocation of real-time streaming applications modeled as dataflow graphs on 2D mesh multi-core processors. The main criteria of the algorithm is to allocate paths that have the highest impact on the execution time of the application first. It is also able to exploit parallelism in the application by allocating parallel paths on different cores. Experimental evaluation shows that the proposed heuristic improves the resource utilization by allocating up to 7% more applications and it minimizes the average end-to-end worst-case response time of the allocated applications by up to 31%.

Abstract
Preemptions via virtual channels have been proposed as a means to introduce the notion of priorities and real-time concepts in wormhole-switched NoC-based architectures. This work presents a holistic approach, which utilises a novel three-staged mapping method in order to assess what should be the physical characteristics of the platform (and its interconnect), such that real-time guarantees can be provided, assuming a given workload. We estimate the "gap" between platform characteristics required for the real-time analysis and those of currently available many-core platforms and propose to employ the existing feature of many-core platforms in order to significantly reduce this gap. The experiments demonstrate that virtual channels, an essential prerequisite for the real-time analysis, are not the bottle-neck. The approach presented in this paper can help system designers to select/design the most suitable platform for a given workload, such that all temporal constraints are met and over-dimensioning is avoided. © 2013 ACM.