Abstract Rockwell's Ada symbolic debugging system (ASDS) is designed especially for use in debugging and testing embedded system software. ASDS uses a combination of software and special hardware to support unobtrusive monitoring, breakpoint and display facilities that can be applied during the development of an embedded system and during the ‘downstream’ stages of the embedded system life cycle associated with production and field unit testing. The ASDS software kernel executes on a stand‐alone monitor processor with modest computational power (e.g. a personal computer), connected to the embedded target system via a target interface that allows the monitor to observe transactions on the target bus in real‐time. The use of a monitor processor with modest power limits the degree of ‘high level’ monitoring support—though ASDS can detect the execution of a particular line of source code or access to a particular variable it contains no facilities for monitoring interactions between high‐level dynamic objects such as tasks. However, the modest power required for the monitor also reduces its costs, with the result that ASDS debugging and test stations have been readily available to engineers working on system development, in production and in the field. Our description of the ASDS design and implementation focuses on its practical solutions to the problems associated with building and maintaining a symbolic debugging system to support embedded system development.

Performance is a high-priority consideration when designing concurrent or distributed systems. The process of designing such a system is complicated by two factors: (1) the current state-of-the-art in concurrent system design is very ad hoc — software design principles for concurrent systems are still in their infancy, and (2) performance evaluation of concurrent systems is quite difficult and it is especially difficult to relate aspects of the design to aspects of the implementation. This paper reports on work with a performance modeling technique for concurrent or distributed systems that allows structured design to be related to the implementation of the concurrency control component of the system. First, a General Process Model (GPM) is used to organize system design information into a six level hierarchy. The abstract performance properties of each level in the hierarchy have been established using concurrency control theory. Next, we describe how to translate the structured system design into efficient concurrency control techniques, using elements of this theory. Finally, a prototype automated design evaluation tool which serves as a central component of the design methodology is described.

The PSEP System represents a novel approach to incremental compilation for block structured languages. PSEP implements a very fine grain, “greedy” approach as a highly concurrent system of two processes: an editor and a code generator. The design allows the two processes to execute without locking their shared data objects, utilizing semantic information about the concurrent system to guarantee the consistency of the shared objects. This design is compared with the more common “demand” approach to incremental compilation.

Data abstraction is an effective tool in the design of complex systems, and the representation independence it provides is a key factor in the maintenance and adaptation of software systems. This paper describes a system development methodology based on the development of hierarchies of abstract data types (ADT's). The methodology preserves a high degree of representation independence throughout both the design and implementation of complex systems. The methodology is illustrated with examples from the design and implementation of a Vision Research Programming System. These examples include ADT specifications, ADT interface specifications, and partial implementation code for the system in two different programming languages, Ada1 and Fortran.

Article Free Access Share on Concurrency control mechanisms and the serializability of concurrent tree algorithms Authors: Ray Ford The University of Iowa, Iowa City, IA The University of Iowa, Iowa City, IAView Profile , Jim Calhoun The University of Iowa, Iowa City, IA The University of Iowa, Iowa City, IAView Profile Authors Info & Claims PODS '84: Proceedings of the 3rd ACM SIGACT-SIGMOD symposium on Principles of database systemsApril 1984 Pages 51–60https://doi.org/10.1145/588011.588020Online:02 April 1984Publication History 9citation387DownloadsMetricsTotal Citations9Total Downloads387Last 12 Months8Last 6 weeks2 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF