http://repub.eur.nl/res/aut/8970/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/464/ 2003-06-26T00:00:00Z This report contains a non-formal motivation and description of ADL-d, a graphical design technique for parallel and distributed software. ADL-d allows a developer to construct an application in terms of communicating processes. The technique distinguishes itself from others by its use of highly orthogonal concepts, and support for automated code generation. Without being committed to one particular design method, ADL-d as a technique can be used from the early phases of application design through phases that concentrate on algorithmic design, and final implementation on some target platform. In this report, we discuss and motivate all ADL-d components, including recently incorporated features such as support for connection-oriented communication, support for modeling dynamically changing communication structures, and a formal semantical basis for each ADL-d component. Also, we discuss our ADL-d implementation, and place ADL-d in context by discussing some related work. http://repub.eur.nl/res/pub/1453/ 1994-01-01T00:00:00Z We have compared three graphical design techniques, OMT, ADL, and PARSE, on their suitability for the development of parallel/distributed applications. Our method has been to use all three of them in modeling one, existing, application: a backup facility running within the Andrew File System. We compare and analyze the outcomes on a number of important design aspects. Based on this, we draw conclusions on each individual technique and on graphical design techniques for parallel/distributed software in general. http://repub.eur.nl/res/pub/1457/ 1994-01-01T00:00:00Z The graphical Hamlet Application Design Language (ADL) has been developed to support the construction of parallel applications. The language is based on a notion of processes communicating by means of message-passing. One of the goals of ADL is that its implementation should allow for automated parallel code generation. However, not every communication construct in ADL has an evident counterpart in present-day target languages. In this report, attention is paid to the implementation of synchronous message-passing between multiple senders and multiple receivers. It is shown how an arbitrary (sender,receiver) pair can be selected in the form of centralized algorithms. The main part of the report, however, focusses on an efficient distributed solution. http://repub.eur.nl/res/pub/1458/ 1994-01-01T00:00:00Z Exploiting parallelism for industrial real-time applications has not received much attention compared to scientific applications. The available real-time design methods do not adequately address the issue of parallelism, resulting still in a strong need for low-level tools such as debuggers and monitors. This need illustrates that developing parallel real-time applications is indeed a difficult and tedious task. In this paper we show how problems can be alleviated if an approach is followed that allows for experimentation with designs and implementations. In particular, we discuss a development system that integrates design, implementation, execution, and analysis of real-time applications, putting emphasis on exploitation of parallelism. In the paper we primarily concentrate on the support for application *design*, as we feel that parallelism should essentially be addressed at this level. http://repub.eur.nl/res/pub/1459/ 1993-01-01T00:00:00Z This report provides an introduction to the definition of the Hamlet Application Design Language (ADL). ADL is a graphical-based language and notation supporting the design of parallel real-time applications. Designs expressed in ADL are based on a model of processes that communicate by message-passing. Communication can either be synchronous or asynchronous, and orthogonally, may be subject to blocking, delaying, or nonblocking timing constraints. The language has been devised in such a way that automated (skeletal) code generation can be supported. To this aim, structural aspects are expressed in a notation somewhat similar to data-flow diagrams, whereas behavioral aspects are expressed as state-transition machines following a syntax similar to that of SDL. Exploitation of parallelism is obtained by annotating a design with process replication specifications. http://repub.eur.nl/res/pub/1460/ 1993-01-01T00:00:00Z The topic of how to exploit parallelism for performance enhancement has already received considerable attention. However, relatively less attention has been paid to practical development techniques for parallel real-time applications. In this paper we propose a graphical design language for supporting the technical design phase in the process of parallel real-time application development. This design language is based on a model of Communicating Sequential Processes and Data Flow Diagrams and supports exploitation of task-oriented and data parallelism. Novel features include, besides support for exploitation of parallelism for real-time applications, a strict separation of behavior and communication specification, specification of timing constraints, integration of control flow and data transformations, and support for automated source code generation The paper also briefly pays attention to the current implementation of the language. http://repub.eur.nl/res/pub/1463/ 1993-01-01T00:00:00Z Designing parallel applications is generally experienced as a tedious and difficult task, especially when hard real-time performance requirements have to be met. This paper discusses on-going work concerning the construction of a Design Entry System which supports the design phase of parallel real-time industrial application development. In particular, in this paper we pay attention to the development and implementation of a graphical Application Design Language. The work is part of the ESPRIT project Hamlet which focuses on industrial application of transputer-based systems for commercially strategic real-time applications.