Building Distributed ADA Applications from Specifications and Functional Components

Durra is a language and support environment for the specification and execution of distributed ADA applications. A Durra programmer describes an application as a collection of processes and data links. More complicated application descriptions may also include a structuring of this collection that varies dynamically according to a set of reconsideration conditions. Each process defined in the application description is associated with an independently compiled ADA subprogram that implements the behavior of that process. The Durra programmer specifies the distribution of application components by assigning them to virtual nodes called clusters. For each cluster, the Durra compiler generates a multithreaded ADA program that imports the code for the processes assigned to that node and manages their execution. Durra also facilitates rapid prototyping through the use of tools that interpret timing specifications associated with processes and generates ADA code to simulate their expected behavior.