Guide to Creating OpenVMS Modular Procedures

This document provides a comprehensive guide for advanced system and application programmers on developing, integrating, and maintaining modular procedures within the OpenVMS operating system environment. It details the principles of modular programming to ensure code consistency, reliability, and reentrancy.

Key topics include:

• Design Principles: How to organize applications, define modular interfaces using explicit and implicit arguments, manage system resources (stack, heap, and static storage), and plan for error handling and signaling.
• Coding Guidelines: Best practices for facility, procedure, file, and PSECT naming conventions. It also covers initializing procedures, writing AST-reentrant code (including strategies for handling race conditions), and invoking user-action routines.
• Testing Procedures: Methodologies for unit testing (black box and white box), language-independence testing, and integration testing, as well as checking procedures for reentrancy and performance analysis.
• Integration and Maintenance: Instructions for creating facility prefixes, object module libraries, and shareable image libraries, along with procedures for maintaining upward compatibility and performing regression testing when updating code.