Distributed Ada-approach and implementation

ABSTRACT

The task of programming distributed applications in Ada may be addressed in several ways. Most of these require the application developer to factor the hardware configuration into software design very early in the development process. The resulting software is sensitive to changes in hardware, does not lend itself to design iteration, is not easily transportable across different hardware configurations, and is not stable against changes during the life-cycle of the application. In Section 2, we describe an approach that achieves separation of concerns between program design and program partitioning for distributed execution. The entire application is written as a single Ada program using the full capabilities of the language for program structuring, separate compilation, and type checking. Then in a distinct second phase of design, the program is partitioned and prepared for distributed execution. The two-phase design approach helps reduce design complexity by problem decomposition, and allows experimentation with different strategies for allocating software to hardware without requiring software redesign. Section 3 reviews other work and presents a comparative evaluation. Two implementations of this approach have been completed and tested with the Ada Compiler Validation Capability (ACVC) test-suite. Implementation issues are discussed, and the key features of our implementation approach are presented in Section 4. Finally, Section 5 concludes the paper with pointers to future work.

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INDEX TERMS

Primary Classification:
  D. Software
  D.2 SOFTWARE ENGINEERING
      D.2.6 Programming Environments

          Nouns: Ada

Additional Classification:
  C. Computer Systems Organization
  C.1 PROCESSOR ARCHITECTURES
      C.1.2 Multiple Data Stream Architectures (Multiprocessors)
          Subjects: Associative processors

General Terms:
Design, Performance