Code generation from hybrid system models is a promising approach to producing reliable embedded systems. this approach presents new challenges as the precise semantics of the model are hard to capture in the code. A ...
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ISBN:
(纸本)0769523560
Code generation from hybrid system models is a promising approach to producing reliable embedded systems. this approach presents new challenges as the precise semantics of the model are hard to capture in the code. A framework for generating code was introduced for single threaded/processor environments. Here, we extend it by considering code generation for distributed environments. We also define criteria for faithful implementation of the model. To this end, we define faulty and missed transitions. For preventing faulty transitions, we build on the idea of instrumentation we have developed for sound simulation of hybrid systems. Finally, we present sufficient conditions to avoid missed transitions and provide examples.
Leasing is a very effective way to improve the performance of distributed algorithms without hampering their fault-tolerance. the notion of lease has traditionally been defined using a global notion of realtime and w...
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ISBN:
(纸本)0769515762
Leasing is a very effective way to improve the performance of distributed algorithms without hampering their fault-tolerance. the notion of lease has traditionally been defined using a global notion of realtime and was hence strongly tied to synchronous system models. this paper introduces a notion of lease devised for an asynchronous system model. We give precise properties of our lease abstraction, and show how it can be implemented in an asynchronous system model with a logical notion of time. We then illustrate its use by showing how it significantly improves the performance of a consensus-based total order broadcast algorithm.
Application programs are performed on clients and issue requests to object servers. the object servers then send responses to the clients. On the other hand, programs named agents move to object servers where the agen...
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For future applications, it is important to develop Systems using small objects. Such systems must be able to provide uninterrupted services even when some small objects stop. Replicating such objects is one way to do...
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ISBN:
(纸本)0769510892
For future applications, it is important to develop Systems using small objects. Such systems must be able to provide uninterrupted services even when some small objects stop. Replicating such objects is one way to do this. However introducing some type of redundancy into systems generally adds some overhead. Our proposed model reduces this overhead. It is implemented with multi-threaded execution for applications in actual systems. We measured the performance of an implementation for applications connected to databases. the results show that the overhead for ordinary execution and the time required to switch the replicas are both acceptably small. this technique will therefore play an important role in future systems.
Static cache analysis for data allocated on the heap is practically impossible for standard data caches. We propose a distinct object cache for heap allocated data. the cache is highly associative to track symbolic ob...
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In this paper we present a new approach to distribute tasks connected by causal dependencies within a heterogeneous environment, e.g. several resources communicating with each other or a processor grid. Our approach u...
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this paper provides a series of lessons learned with respect to using performance modeling and analysis techniques on designs of object-oriented software systems. Specifically it focuses on the application of the Unif...
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Sensor networks introduce a new application domain and set of challenges in distributedcomputing including new network-level programming languages, global system abstractions, and general-purpose communication protoc...
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ISBN:
(纸本)9780769527659
Sensor networks introduce a new application domain and set of challenges in distributedcomputing including new network-level programming languages, global system abstractions, and general-purpose communication protocols. these challenges are brought about by the tight integration of computation, communication, and distributedreal-time interaction withthe physical world. Withthe growing interest in interconnecting different sensor networks across a wide-area communication infrastructure, an overarching challenge becomes one of arriving at an agreed-upon global sensor network architecture that ensures interoperability. Unlike the Internet, where a layered communication stack (namely, the TCP/IP stack) defines the network architecture, a sensor network architecture must unify not only communication interfaces but also programming interfaces, sit-ice network communication and computation functions are tightly intertwined. In that sense, the sensor network architecture refers to a layered stack of distributedcomputing abstractions. this paper presents an architecture and key considerations in designing and interconnecting local and global sensor networks. Candidate protocols and middleware instantiations are described from the authors' ongoing work that meet the discussed considerations.
Developers of mission-critical distributedreal-time and embedded (DRE) systems face a fundamental tension between (1) the performance gains achievable with hand-crafted optimizations to systems built largely from scr...
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ISBN:
(纸本)0769515762
Developers of mission-critical distributedreal-time and embedded (DRE) systems face a fundamental tension between (1) the performance gains achievable with hand-crafted optimizations to systems built largely from scratch and (2) the development cost and cycle-time reductions offered by common off-the-shelf (COTS) middleware. this paper describes how the Kokyu portable middleware scheduling framework,, which is built using standards-based COTS middleware and OS primitives, can be used both to (1) maintain the flexibility and reuse offered by COTS middleware and (2) provide opportunities for domain-specific optimizations that are needed to meet stringent real-time performance requirements.
this paper presents a method to analyze the timing behavior of an event-based real-time protocol composition framework. the framework, called RT-Appia, allows the development and implementation of configurable real-ti...
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ISBN:
(纸本)0769515762
this paper presents a method to analyze the timing behavior of an event-based real-time protocol composition framework. the framework, called RT-Appia, allows the development and implementation of configurable real-time protocol stacks. the method performs the schedulability analysis for events flowing in a real-time channel and is based on the holistic theory for distributedreal-time systems. To illustrate the use of the model, a stack of modular reliable group communication protocols for the CAN field-bus is analyzed and the collected results are compared with previous work.
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