Determining Concurrency in Object-Oriented Design of Real-Time Embedded Systems Using Ada.

摘要

One of the characteristics of real-time systems is concurrency. Designers of real-time systems have traditionally determined system concurrency at implementation time using the facilities of a cyclic executive. With the advent of programming language constructs for specifying concurrency, determining concurrency at design time has become a possibility. Several design methods, all of which are extensions of either Structured Design or Jackson System Development, provide heuristics to help the designer make concurrency decisions. The object-oriented approach, however, has no corresponding heuristics to aid designers of real-time systems. The purpose of this thesis was to develop heuristics to help designers make concurrency decisions in developing object-oriented designs of real-time systems. This was accomplished by examining existing heuristics from other design methods and applying them to the object-oriented paradigm. Four heuristics were developed, the first of which exploits the potential in object-oriented design to model the problem-space. The other three heuristics deal with concurrency which is not necessarily reflected in the problem-space, but must be implemented for practical reasons. The heuristics were validated by applying them to a sample problem, then having the heuristics and the design of the sample problem evaluated by a group of software engineering experts. (KR)