HARNESS is an experimental metacomputing system based upon the principle of dynamically reconfigurable, object-oriented, networked computing frameworks. HARNESS supports reconfiguration not only in terms of the comput...
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HARNESS is an experimental metacomputing system based upon the principle of dynamically reconfigurable, object-oriented, networked computing frameworks. HARNESS supports reconfiguration not only in terms of the computers and networks that comprise the virtual machine, but also in the capabilities of the VM itself. These characteristics allow the construction of modular programming environments that can be plugged into the HARNESS system on demand. As a proof of concept exercise, and also with an intent to provide a flexible coordination facility for the HARNESS system, Sun's JAVASPACE interface was implemented as a HARNESS plug-in. The JAVASPACES model is part of the JAVA distributed computing effort and is essentially an object-oriented tuple-space. JAVASPACES technology is a simple unified mechanism for dynamic communication, coordination, and sharing of objects between JAVA technology-based network resources. This paper introduces the HARNESS system and discusses design, implementation, and preliminary experiences with the JAVASPACE for HARNESS. (C) 2000 Academic Press.
Increasing numbers of software developers are using the Unified Modeling Language (UML) and associated visual modeling tools as a basis for the design and implementation of their distributed, component-based applicati...
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ISBN:
(纸本)9781581132663
Increasing numbers of software developers are using the Unified Modeling Language (UML) and associated visual modeling tools as a basis for the design and implementation of their distributed, component-based applications. At the same time, it is necessary to test these components, especially during unit and integration *** Siemens Corporate Research, we have addressed the issue of testing components by integrating test generation and test execution technology with commercial UML modeling tools such as Rational Rose; the goal being a design-based testing environment. In order to generate test cases automatically, developers first define the dynamic behavior of their components via UML Statecharts, specify the interactions amongst them and finally annotate them with test requirements. Test cases are then derived from these annotated Statecharts using our test generation engine and executed with the help of our test execution tool. The latter tool was developed specifically for interfacing to components based on COM/DCOM and CORBA *** this paper, we present our approach to modeling components and their interactions, describe how test cases are derived from these component models and then executed to verify their conformant behavior. We outline the implementation strategy of our TnT environment and use it to evaluate our approach by means of a simple example.
A dynamic system is one which changes its configuration as it runs. It is a system two which, we can drop new components which then cooperate with the existing ones. Such systems are necessarily built from reusable co...
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ISBN:
(纸本)0818683775
A dynamic system is one which changes its configuration as it runs. It is a system two which, we can drop new components which then cooperate with the existing ones. Such systems are necessarily built from reusable components, since as soon as the system is reconfigured to use some new components, those new components must reuse the existing, still running, ones. Design of reusable components in this context is an important problem. We suggest three laws which such reusable components might be required to obey, if dynamic systems are to be effective and to be economically built. We illustrate our conjecture that the laws are effective by describing a generic architecture based on the familiar registry services of COM/OLE or CORBA and by describing a simple point-of-sale system built according to this architecture. We conclude, of course, that some interesting open questions remain. Bur we suggest that an approach to reuse based on refining the three laws is a promising direction for system architecture to take.
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