From ARTEMIS Requirements to a Cross-Domain Embedded System Architecture

International audienceThis paper gives an overview of the cross-domain component-based architecture GENESYS for embedded systems. The development of this architecture has been driven by key industrial challenges identified within the ARTEMIS Strategic Research Agenda (SRA) such as composability, robustness and integrated resource management. GENESYS is a platform architecture that provides a minimal set of core services and a plurality of optional services that are predominantly implemented as self-contained system components. Choosing a suitable set of these system components that implement optional services, augmented by application specific components, can generate domain-specific instantiations of the architecture (e.g., for automotive, avionic, industrial control, mobile, and consumer electronics applications). Such a cross-domain approach is needed to support the coming Internet of Things, to take full advantage of the economies of scale of the semiconductor industry and to improve productivity

AMADEOS SysML Profile for SoS Conceptual Modeling

International audienc

Flexible and dynamic replication control for interdependent distributed real-time embedded systems

Replication is a proven concept for increasing the availability of distributed systems. However, actively replicating every software component in distributed embedded systems may not be a feasible approach. Not only the available resources are often limited, but also the imposed overhead could significantly degrade the system’s performance. This paper proposes heuristics to dynamically determine which components to replicate based on their significance to the system as a whole, its consequent number of passive replicas, and where to place those replicas in the network. The activation of passive replicas is coordinated through a fast convergence protocol that reduces the complexity of the needed interactions among nodes until a new collective global service solution is determined

Proving Determinacy of the PharOS Real-Time Operating System

International audienceExecutions in the PharOS real-time system are deterministic in the sense that the sequence of local states for every process is independent of the order in which processes are scheduled. The essential ingredient for achieving this property is that a temporal window of execution is associated with every instruction. Messages become visible to receiving processes only after the time window of the sending message has elapsed. We present a high-level model of PharOS in TLA+ and formally state and prove determinacy using the TLA+ Proof System

basic concepts on systems of systems

A System of System (SoS) stems from the integration of existing systems (legacy systems), normally operated by different organizations, and new systems that have been designed to take advantage of this integration

A Byzantine-Fault Tolerant Self-Stabilizing Protocol for Distributed Clock Synchronization Systems

Embedded distributed systems have become an integral part of safety-critical computing applications, necessitating system designs that incorporate fault tolerant clock synchronization in order to achieve ultra-reliable assurance levels. Many efficient clock synchronization protocols do not, however, address Byzantine failures, and most protocols that do tolerate Byzantine failures do not self-stabilize. Of the Byzantine self-stabilizing clock synchronization algorithms that exist in the literature, they are based on either unjustifiably strong assumptions about initial synchrony of the nodes or on the existence of a common pulse at the nodes. The Byzantine self-stabilizing clock synchronization protocol presented here does not rely on any assumptions about the initial state of the clocks. Furthermore, there is neither a central clock nor an externally generated pulse system. The proposed protocol converges deterministically, is scalable, and self-stabilizes in a short amount of time. The convergence time is linear with respect to the self-stabilization period. Proofs of the correctness of the protocol as well as the results of formal verification efforts are reported

Going Beyond Deadline-Driven Low-level Scheduling in Distributed Real-Time Computing Systems

Abstract: In real-time computing systems, timing-requirement specifications coming from the application designer are the obvious primary driver for resource allocation. Deadline-driven scheduling of computation-segments has been studied as an advanced mode of scheduling devised to meet the timing requirement specifications. However, it does not reflect additional concerns of the application designer, the damaging impacts of various timing violations on the application. The notion of risk-incursion function (RIF) as a framework for specification of such damaging impacts has been established by the first co-author. In this paper, a concrete implementation approach of the RIFdriven resource allocation scheme is discussed first. Then two RIF-based scheduling algorithms are discussed. The results of the experiment conducted to compare the performance of RIF-based scheduling algorithms against that of deadline-driven scheduling algorithms are also provided