We propose a new, minimal specification for real-time Java,for safety critical applications. the intention is to provide a profile that supports programming of applications that can be validated against safety critica...
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ISBN:
(纸本)9780769527659
We propose a new, minimal specification for real-time Java,for safety critical applications. the intention is to provide a profile that supports programming of applications that can be validated against safety critical standards such as DO-178B[15]. the proposed profile is in line withthe Java specification request JSR-302: Safety Critical Java Technology, which is still under discussion. In contrast to the current direction of the expert group for the JSR-302 we do not subset the rather complex real-time Specification for Java (RTSJ). Nevertheless, our profile can be implemented on top of an RTSJ compliant JVM.
the stringent performance requirements of distributedreal-time embedded systems often require highly optimized implementations of middleware services. Performing such optimizations manually can be tedious and error-p...
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ISBN:
(纸本)0769523560
the stringent performance requirements of distributedreal-time embedded systems often require highly optimized implementations of middleware services. Performing such optimizations manually can be tedious and error-prone. this paper proposes a model-driven approach to generate customized implementations of event ordering services in the context of component based systems. Our approach is accompanied by a number of tools to automate the customization. Given an application App, an event ordering service Order and a middleware platform P, we provide tools to analyze high-level specifications of App to extract information relevant to event ordering and to use the extracted application information to obtain a customized service, Order(App), with respect to the application usage.
Requirements of High Integrity systems now encompass distribution mechanisms along with strong functional and non-functional features (run-time support for hardware, dependability, safety, analyzability). In this pape...
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ISBN:
(纸本)9780769527659
Requirements of High Integrity systems now encompass distribution mechanisms along with strong functional and non-functional features (run-time support for hardware, dependability, safety, analyzability). In this paper, we show how model processing help addressing such needs. We present a generic distribution model suitable for High Integrity systems, and demonstrate how a high-level modeling deployment view allows one to greatly reduce the model complexity. Finally, we conclude by assessing a case study.
EarlGray is a component-based Java virtual machine (JVM) that can be configured to satisfy various kinds of requirements for building future information appliances and embedded systems. While the modification and exte...
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ISBN:
(纸本)0769523560
EarlGray is a component-based Java virtual machine (JVM) that can be configured to satisfy various kinds of requirements for building future information appliances and embedded systems. While the modification and extension on an existing JVM tend to be done in an ad-hoe manner, EarlGray allows developers to customize the JVM in a systematic manner by decomposing it into components and the explicit descriptions of the relationship between the components. We also examine three case studies on the customization of the EarlGray: exchanging a scheduler, memory management, and class file verifier components. these case studies shows the benefits and drawbacks of the current component-based technologies.
Modular component-based robot systems require not only an infrastructure for component management, but also scalability as well as real-time properties. Robot Technology (RT)-Middleware is a software platform for such...
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ISBN:
(纸本)9780769535739
Modular component-based robot systems require not only an infrastructure for component management, but also scalability as well as real-time properties. Robot Technology (RT)-Middleware is a software platform for such component-based robot systems. Each component in the RT-Middleware, so-called "RT-component" supporting particular robot functions, is based on Common object Request Broker Architecture (CORBA). Unfortunately, the RT-Middleware lacks the mechanism for real-time control. In this paper, we extend the framework of the RT-components to take care of timing constraints. We first enable tasks to have different periods within each RT-component. We then modify the packet format of the General Inter-ORB Protocol (GIOP) to transfer the information of timing constraints over RT-components. the performance evaluation on ART-Linux shows that the extended RT-component framework improves the schedulability of distributedreal-time tasks, without causing critical overheads in unmarshaling the modified GIOP packets.
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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ISBN:
(纸本)9780769527659
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 safer failure detectors for a protocol solving the problem of global data computation.
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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ISBN:
(纸本)9780769527659
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.
Many emerging embedded systems consist of multiple embedded nodes, which are connected through an internal small area network. In such systems, the synchronization between the embedded nodes is essential to provide re...
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ISBN:
(纸本)9780769535739
Many emerging embedded systems consist of multiple embedded nodes, which are connected through an internal small area network. In such systems, the synchronization between the embedded nodes is essential to provide real-time cooperation environment. On small area networks, the severe obstacle for achieving real-time synchronization is the unpredictable overhead of the system software running on the embedded nodes. this is true especially if a traditional operating system has been installed. Despite of these drawbacks, it is quite common to run traditional operating systems on some of the embedded nodes to utilize various existing applications. In this paper, we propose a novel design of communication primitives called RTDiP-Sync for real-timedistributed synchronization over small area networks. Experiment results show that the suggested design can minimize the communication overhead and provide better overhead prediction.
Quality and risk concerns currently, limit the application of commercial off-the-shelf (COTS) software components to non-critical applications. Software metrics can quantify factors contributing to the overall quality...
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ISBN:
(纸本)0769519288
Quality and risk concerns currently, limit the application of commercial off-the-shelf (COTS) software components to non-critical applications. Software metrics can quantify factors contributing to the overall quality, of a component-based system, and models for tradeoffs between cost and various aspects of quality can guide quality and risk management by identifying and eliminating sources of risk. this paper discusses metrics and models that can be used to alleviate quality concerns for COTS-based systems, enabling the use of COTS components in a broader range of applications.
Almost a year ago, Microsoft has introduced the .NET architecture as a new component-based programming environment, which allows for easy integration of classical distributed programming techniques with Web computing....
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ISBN:
(纸本)0769515584
Almost a year ago, Microsoft has introduced the .NET architecture as a new component-based programming environment, which allows for easy integration of classical distributed programming techniques with Web computing. NET defines a type system and introduces notions such as component, object, and interface, which are building blocks for distributed multi-language component-based applications. As many other component frameworks, NET mainly focuses on functional interfaces of components. Nonfunctional aspects of components, such as resource usage (CPU, memory), timing behavior, fault-tolerance, or security requirements are currently not expressed in NET's component interfaces. Within this paper, we discuss the usage of aspect-oriented programming techniques in context of the NET framework. We focus on the fault-tolerance aspect and discuss the expression of non-functional component properties (aspects) as C# custom attributes. Our approach uses reflection to generate replicated objects based on settings of a special "fault-tolerance" attribute for C# components(perpendicular to). We have implemented an aspect-weaver for integration of aspect-code and component-code, which uses the mechanisms of the language-neutral NET type system. therefore, our approach is not restricted to the C# language but works for an), of the NET programming languages.
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