Andrew M. Lister

A review of Ada tasking

1 Introduction.- 2 The Ada Tasking model.- 3 Formal aspects.- 4 Concurrent programming.- 5 Embedded systems.- 6 Distributed systems.- 7 Implementation issues.- 8 Language changes and extensions.- 9 Conclusion.

The problem of nested monitor calls

The concept o f a moni tor has been developed by }bare [1] and Brincb-Hansen [2, 3, 4] i n to a powerful and u se fu l too l for b u i l d i n g w e l l s t r u c t u r e d and r e l i a b l e ope ra t ing systems. Some expe r i ence of the author in c o n s t r u c t i n g moni to r -based systems [5, 6] has h i g h ] i g h t e d a problem of implementa t ion which does not seem to have been e x p l i c i t l y addressed in the literature. This article describes the problem mld discusses some (inadequate) solutions; its aim is to solicit better solutions from workers in the field.

A comparative study of task communication in ada

A previous paper compared the mechanisms for process communication in Hoares communicating sequential processes and in Brinch Hansens distributed processes, by both qualitative and quantitative analyses. This paper extends these analyses to the corresponding features for communication between tasks in Ada. The similarity between Adas features and Hoares proposals is confirmed, but some limitations on non‐determinism in Ada are noted.

A Comparison of Two Notations for Process Communication

This paper compares the mechanisms for process communication, synchronisation and non-determinism in recent language proposals by Hoare and Brinch Hansen, by both qualitative and quantitative analyses. A significant variation in effectiveness with program class is shown.

An Experiment in Software Science

This paper describes an experiment which was undertaken for two purposes: firstly to test the applicability of software science in the realm of student programming, and secondly to obtain quantitative inferences about the programming language PASCAL. The results suggest that software science offers little in the area studied, and possible reasons for this are discussed.

Design of dependable real-time systems

Traditional software development techniques have proved inadequate for developing dependable real-time systems. Non-functional concerns, such as timeliness, reliability and safety, are typically introduced on an ad-hoc basis, often late in the development process when the design is difficult to change. Experience shows that this approach fails to produce cost-effective dependable systems. Development of dependable real-time systems also calls for new forms of abstraction. In such systems the target execution environment constrains the feasible designs and realisable non-functional goals. Hence there is a need to consider such constraints early in the design process. Abstractions which hide crucial detail are inappropriate; nevertheless, abstractions are obviously needed if the development process is to be successfully managed.

Design of dependable real-time systems (extended abstract)

Summary form only given. In this presentation, the current challenges to the power sector are illustrated. The main pillars of the strategy of power sector and their justifications are presented and discussed. The draft of the new electricity law is presented including how the law has handled the strategic targets. Also, the impact of the law on; the structure of the power sector, development of renewable energy and supporting energy efficiency, is discussed. Finally the challenges facing the reforms are presented.