distributed programming is applicable in a wide range of domains such as control systems, These systems are subject to mutable environments and must also provide a time varying adaptive set of functionalities. An adap...
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ISBN:
(纸本)0769515762
distributed programming is applicable in a wide range of domains such as control systems, These systems are subject to mutable environments and must also provide a time varying adaptive set of functionalities. An adaptive system is defined by means of two main features: (i) an approach to specify the correspondence between objects and resources and (ii) the related mechanisms to assure dynamically the right set Of objects running. The conditional dependency concept has proven to be an efficient way to specify this kind of correspondence between resources and objects for adaptive systems in the context of multimedia distributed processing (ServiMidia Project [1]). This paper presents a framework for designing general purpose adaptive systems anchored on the concept of conditional dependencies. As the use of such approach may lead to inconsistent system behaviour when specifying very large systems, we show that it is easy to design verification tools based on the same framework mechanisms.
This paper provides two contributions to the study of mechanisms for reducing the life-cycle costs of distributedreal-time and embedded (DRE) systems. First, we present a mechanism-called a Quality Connector-that ena...
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ISBN:
(纸本)0769515762
This paper provides two contributions to the study of mechanisms for reducing the life-cycle costs of distributedreal-time and embedded (DRE) systems. First, we present a mechanism-called a Quality Connector-that enables applications to specify the qualities of service that they require from their infrastructure, and then manages the operations that optimize the middleware to implement those requirements. Second, we show how Quality Connectors are being applied in practice to allocate communication resources automatically, for real-time CORBA event propagation. Although middleware that configures itself in response to quality of service (QoS) requests has been investigated and applied in general-purpose computing contexts, we believe that the present work, is among the first to put such capabilities into mission-critical DRE systems with stringent QoS requirements.
The distributedreal-time services are developing as a new programming paradigm of the distributedobjectcomputing systems. For supporting these services, we construct a new model of a real-timeobject group (RTOG) p...
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In distributedcomputing environment, there lacks for methodologies on how to model communication mechanisms of distributedobjects and to facilitate the later implementation of the model, In this paper, a solution is...
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ISBN:
(纸本)0780370872
In distributedcomputing environment, there lacks for methodologies on how to model communication mechanisms of distributedobjects and to facilitate the later implementation of the model, In this paper, a solution is presented to describe and model the communication of distributedobjects in an object-oriented enterprise model even with real-time requirements. The steps include the analysis of entities, communication requirements, and communication mechanisms involving UML (Unified Modeling Language) diagrams, while capable of finishing data flow, control flow, object operations and the method definitions at the same time. ne solution is based on and demonstrated by the distributed extension version of UML, in which time control and complex message mechanism are introduced.
This paper presents a lightweight CORBA fault-tolerance service called FTS. The service is based on standard portable features of CORBA, and in that respect is fully CORBA compliant, but does not follow the FT-CORBA s...
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ISBN:
(纸本)0769515762
This paper presents a lightweight CORBA fault-tolerance service called FTS. The service is based on standard portable features of CORBA, and in that respect is fully CORBA compliant, but does not follow the FT-CORBA specifications in areas where the authors felt the latter interfered with their other design goals. The service feat a res a unique architecture, based on a new type Of(172 object adaptor, called Group object Adaptor (GOA). The service is portable, interoperable, and aims for simplicity and high-performance request processing. Moreover, the service supports network, partitions, some aspects of non-deterministic processing, and mixing ORBs of different vendors in the same fault-tolerance infrastructure. The paper also presents an analysis of the differences between the service design and FT-CORBA, With the hope Of stimulating a discussion about future improvements to the FT-CORBA standard.
object-oriented programming languages are extensively used in real-time systems. When calculating the worst case execution time for object-oriented programs one needs flow information, such as loop bounds and informat...
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object-oriented programming languages are extensively used in real-time systems. When calculating the worst case execution time for object-oriented programs one needs flow information, such as loop bounds and information on infeasible paths. In most cases, the programmer is expected to supply these as manual annotations. This paper presents a prototype tool which calculates this information automatically for realtimeTalk (RTT) programs. KIT is a real-time version of the object-oriented language Smalltalk. We also show the analysis of a number of example programs.
The emerging distributed applications require end-to-end support for various quality-of-service (QoS) aspects, including bandwidth, latency, jitter, and dependability. The Common object Request Broker Architecture (CO...
Although high-level real-timedistributedcomputingobjects are generally written in forms independent of execution platforms, input and output (I/O) activities involving peripherals are inherently platform-dependent....
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Although high-level real-timedistributedcomputingobjects are generally written in forms independent of execution platforms, input and output (I/O) activities involving peripherals are inherently platform-dependent. Yet, writing parts of real-timeobjects for controlling peripherals should be done in forms compatible with the adopted real-timeobject programming styles. Basic issues are discussed in the context of an object-orientedreal-time programming scheme called the time-triggered message-triggered object (TMO) programming scheme. A desirable goal here is to facilitate both commanding and reactive control of peripherals in TMOs in general forms while enabling relatively easy analysis of the timing behavior of such TMOs. This paper presents several techniques to meet these requirements.
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