The Graph Layout Toolkit is a family of portable graph drawing and layout libraries designed for integration into graphical user interface application programs. When visualizing graphs, it becomes essential to communi...
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XML users can make their own document structure and tagsets by freely defining the DTD with their intention. This freedom of defining tagsets and the structures, however, prevents the interchange of an XML document be...
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A multidatabase system provides integrated access to heterogeneous, autonomous component databases in a distributed system. In order to gain integrated access to a multidatabase system, semantic heterogeneities have t...
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Recently, object-oriented (OO) frameworks have been known to be highly effective and practical for software reuse;as shown in San Francisco project, a large-scaled industry project for framework development. However, ...
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One of the most attractive features of computer-controlled systems should be the ease with which they can be modified to incorporate improvements and new capabilities. It would be desirable to make the software change...
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One of the most attractive features of computer-controlled systems should be the ease with which they can be modified to incorporate improvements and new capabilities. It would be desirable to make the software changes in a safe and reliable fashion while the system is running. The Simplex architecture, a real-time software technology developed at the Carnegie Mellon University softwareengineering Institute, is designed for this purpose. We introduce the basic structure of the Simplex architecture and describe the types of faults it can handle. We describe the fault detection mechanism based on the trajectories of the physical system in its state space, and derive the control switching logic that determines which controller is chosen to control the physical system in each sampling period.
This paper addresses how domain analysis served to help create reusable architectures and components in the development of a real-time embedded system. The resulting product is Motorola's FLEX™ Kernel, a set of co...
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We describe a system that supports source-level integration of ML-like functional language code with ANSI C or Ada83 code. The system works by translating the functional code into type-correct, 'vanilla' C or ...
We describe a system that supports source-level integration of ML-like functional language code with ANSI C or Ada83 code. The system works by translating the functional code into type-correct, 'vanilla' C or Ada;it offers simple, efficient, type-safe inter-operation between new functional code components and 'legacy' third-generation-language components. Our translator represents a novel synthesis of techniques including user-parameterized specification of primitive types and operators;removal of polymorphism by code specialization;removal of higher-order functions using closure datatypes and interpretation;and aggressive optimization of the resulting first-order code, which can be viewed as encoding the result of a closure analysis. Programs remain fully typed at every stage of the translation process, using only simple, standard type systems. Target code runs at speeds comparable to the output of current optimizing ML compilers, even though handicapped by a conservative garbage collector.
We describe a language for defining term rewriting strategies, and its application to the production of program optimizers. Valid transformations on program terms can be described by a set of rewrite rules; rewriting ...
ISBN:
(纸本)9781581130249
We describe a language for defining term rewriting strategies, and its application to the production of program optimizers. Valid transformations on program terms can be described by a set of rewrite rules; rewriting strategies are used to describe when and how the various rules should be applied in order to obtain the desired optimization effects. Separating rules from strategies in this fashion makes it easier to reason about the behavior of the optimizer as a whole, compared to traditional monolithic optimizer implementations. We illustrate the expressiveness of our language by using it to describe a simple optimizer for an ML-like intermediate *** basic strategy language uses operators such as sequential composition, choice, and recursion to build transformers from a set of labeled unconditional rewrite rules. We also define an extended language in which the side-conditions and contextual rules that arise in realistic optimizer specifications can themselves be expressed as strategy-driven rewrites. We show that the features of the basic and extended languages can be expressed by breaking down the rewrite rules into their primitive building blocks, namely matching and building terms in variable binding environments. This gives us a low-level core language which has a clear semantics, can be implemented straightforwardly and can itself be optimized. The current implementation generates C code from a strategy specification.
作者：
Frank HoudekKurt SchneiderEva WieserDaimler-Benz AG
Research and Technology P.O. Box 23 60 89013 Ulm Germany and University of Ulm Faculty of Computer Science Dept. Software Engineering 89069 Ulm Germany Daimler-Benz AG
Research and Technology P.O. Box 23 60 89013 Ulm Germany
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