Modeling distributed termination with pre-defined partial termination ordering

Abstract

Distributed termination convention (DTC) adopted by most of the concurrent programming languages, is attractive because the programmer is relieved of the control details to achieve termination of distributed programs. This model, however, is not very convincing from the implementation point of view as the communication overhead involved in achieving termination is enormous, especially in a distributed system. The paper provides a new approach for distributed process termination. DTC is modeled with local termination control and termination ordering relation represented by directed acyclic graph (DAG). This approach adheres to the programming language design principle-'preservation of information' which says that a language should allow the representation of information that the user might know and that the compiler might need. The termination information required by this technique may be entered with the source code (new syntax) to the compiler for analysis. Alternatively, most languages, such as CSP and Ada, contain enough information in the source code to allow for automatic analysis provided termination ordering information is supplied in a suitable form (e.g. DAG). This can be done with an intelligent preprocessor to the source code or with modification to the compiler itself. The execution of a specific program then becomes more efficient with this distributed termination. DTC with semantic termination dependencies should be provided as an option in the supporting environment for a concurrent language. >