The IOA Language and Toolset: Support for Designing, Analyzing, and Building Distributed Systems

This report describes a new language for distributed programming, the IOA language, together with a high-level design and preliminary implementation for a suite of tools, the IOA toolset, to support the production of high-quality distributed software. The language and tools are based on the I/O automaton model, which has been used to describe and verify distributed algorithms. The toolset supports a development process that begins with a high-level speciica-tion, reenes that speciication via successively more detailed designs, and ends by automatically generating distributed programs. The toolset encourages system decomposition, which helps make distributed programs understandable and easy to modify. It also provides a variety of validation methods (theorem proving, model checking, and simulation), which can be used to ensure that the generated programs are correct, subject to assumptions about externally-provided system services (e.g., communication services), and about the correctness of hand-coded data type implementations.