Procedural Events as Software Interrupts.

摘要

The paper deals with procedural events, providing a basis for synchronization and scheduling, particularly applied on real-time program systems of multiple parallel activities (multi-task). There is a great need for convenient scheduling mechanisms for minicomputer systems as used in process control, but so far mechanisms somewhat similar to those proposed here found only in PL/1 among the generally known high-level languages. PL/1, however, is not very common on computers of this size. Also, the mechanisms in PL/1 seem more restricted, as compared to those proposed here. A new type of boolean program variable, the EVENTMARK, is proposed. Eventmarks represent events of any kind that may occur within a computational process and are believed to give very efficient and convenient activation and scheduling of program modules in a real-time system. An eventmark is declared similar to a procedure, and the proposed feature could easily be amended as an extension to existing languages, as well as incorporated in future language designs. (Author)