In this paper, we present a prototype of the real-time Systems Compiler (RTSC). the RTSC is a compiler-based tool that enables the migration from event-triggered to time-triggered real-time systems. this is achieved b...
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In this paper, we present a prototype of the real-time Systems Compiler (RTSC). the RTSC is a compiler-based tool that enables the migration from event-triggered to time-triggered real-time systems. this is achieved by replacing the real-time systems architecture of a given real-time system. the real-time systems architecture governs the structural properties of the white-box view of a real-time system: how are tasks attached to events and how are dependencies between different tasks implemented. the RTSC uses an abstraction called Atomic Basic Blocks (ABBs) to hide the real-time systems architecture and capture all relevant dependencies of an event-triggered system in a global ABB-graph. the RTSC automatically extracts that ABB-graph from an event-triggered real-time system given as source code, transforms that ABB-graph appropriately, and maps it to a statically computed schedule that could be executed by standard time-triggered real-time operating systems. Important temporal properties of the physical environment of the real-time system needed for that transformation are stored in a system model provided as additional input to the RTSC. Furthermore, we demonstrate the applicability of our approach and the operation of our prototype by transforming an event-triggered control application into a time-triggered equivalent. Copyright (C) 2011 John Wiley & Sons, Ltd.
As quality of service (QoS)-enabled component middleware technologies gain widespread acceptance to build distributedreal-time and embedded (DRE) systems, it becomes necessary for these technologies to support real-t...
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As quality of service (QoS)-enabled component middleware technologies gain widespread acceptance to build distributedreal-time and embedded (DRE) systems, it becomes necessary for these technologies to support real-time publish/subscribe services, which is a key requirement of a large class of DRE systems. To date there have been very limited systematic studies evaluating different approaches to integrating real-time publish/subscribe services in QoS-enabled component middleware. this paper makes two contributions in addressing these key research questions. First, we evaluate the pros and cons of three different design alternatives for integrating publish/subscribe services within QoS-enabled component middleware. Second, we empirically evaluate the performance of our container-based design and compare it with mature object-orientedreal-time publish/subscribe implementations. Our studies reveal that boththe performance and scalability of our design and implementation are comparable to its object-oriented counterpart, which provides a key guidance to the suitability of component technologies for DRE systems.
We present a tool-supported approach to the validation of system-level timing properties in formal models of distributedreal-time embedded systems. Our aim is to provide system architects with rapid feedback on the t...
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Many emerging applications operate on continuous unbounded data streams and need real-time data services. Providing deadline guarantees for queries over dynamic data streams is a challenging problem due to bursty stre...
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Many emerging applications operate on continuous unbounded data streams and need real-time data services. Providing deadline guarantees for queries over dynamic data streams is a challenging problem due to bursty stream rates and time-varying contents. this paper presents a prediction-based QoS management scheme for real-time data stream query processing in distributed environments. the prediction-based QoS management scheme features query workload estimators, which predict the query workload using execution time profiling and input data sampling. In this paper, we apply the prediction-based technique to select the proper propagation schemes for data streams and intermediate query results in distributed environments. the performance study demonstrates that the proposed solution tolerates dramatic workload fluctuations and saves significant amounts of CPU time and network bandwidth with little overhead
this paper provides three contributions to the study of quality of service (QoS) configuration in component-based DRE systems. First, we describe the challenges associated with mapping the platform-independent QoS pol...
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this paper provides three contributions to the study of quality of service (QoS) configuration in component-based DRE systems. First, we describe the challenges associated with mapping the platform-independent QoS policies of an application into platform-dependent values of QoS parameters used to configure the behavior of QoS-enabled component middleware. Second, we describe a novel approach that uses model-transformation to map these QoS policies onto component middleware QoS configuration parameters. third, we demonstrate the use of model-checking to verify the properties of the transformation and automate the synthesis of configuration parameters required to tune the QoS-enabled component middleware. Our results indicate that model-transformation and model-checking provide significant benefits with respect to automation, reusability, verifiability, and scalability of the QoS mapping process compared with conventional middleware configuration techniques
Nowadays, there are many protocols able to cope with process crashes, but, unfortunately, a process crash represents only a particular faulty behavior. Handling tougher failures (e.g. sending omission failures, receiv...
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Nowadays, there are many protocols able to cope with process crashes, but, unfortunately, a process crash represents only a particular faulty behavior. Handling tougher failures (e.g. sending omission failures, receive omission failures, arbitrary failures) is a real practical challenge due to malicious attacks or unexpected software errors. this paper proposes a component-based methodology allowing to take a protocol A resilient to crash failures and to add software components, namely liveness and safety failure detectors, in order to adapt the protocol A to be resilient to more general failures than crashes, without changing the code of A. then, the feasibility of this approach is shown, by providing an implementation of liveness failure detectors and of safety failure detectors for a protocol solving the problem of global data computation
In many software development projects, performance requirements are not addressed until after the application is developed or deployed, resulting in costly changes to the software or the acquisition of expensive high-...
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In many software development projects, performance requirements are not addressed until after the application is developed or deployed, resulting in costly changes to the software or the acquisition of expensive high-performance hardware. To remedy this, researchers have developed model-driven performance analysis techniques for assessing how well performance requirements are being satisfied early in the software lifecycle. In some cases, companies may not have the expertise to perform such analysis on their software; therefore they have an independent assessor perform the analysis. this paper describes an approach for conducting independent model-driven software performance assessments of UML 2.0 designs and illustrates this approach using a real-time signal generator as a case study
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