On developing and verifying design abstractions for reliable concurrent programming in Ada

Ada 95 is an expressive concurrent programming language, which allows building large multi-tasking applications. Much of the complexity of these applications stems from the interactions between the tasks. Design abstractions (such as atomic actions, conversations etc.) have been proposed to deal with such complexity. This paper argues that Petri nets offer a promising, tool-supported, technique for checking the logical correctness of abstractions. The paper illustrates the effectiveness of this approach by showing the correctness of an Ada implementation of the atomic action protocol using a variety of Petri net tools.