OpenVMS Programming Concepts Manual

This manual serves as a comprehensive guide for system and application programmers on the OpenVMS operating system's features and programming environment. It covers core concepts of process management, including the creation of subprocesses and detached processes, inter-process communication via mechanisms like event flags, logical names, mailboxes, and global sections, and process control such as scheduling, suspension, and deletion.

The document also details system functionalities such as handling asynchronous system traps (ASTs), managing system time and date formats, and utilizing Run-Time Library (RTL) routines to access operating system components, including I/O operations and VAX machine instructions. File operations, system service I/O, logical name services, and distributed name services (VAX Only) are explained to support robust application development.

Advanced topics include using the Distributed Transaction Manager for ensuring data integrity, understanding and implementing condition-handling routines for error management, and synchronizing data access and program operations in both uniprocessor and multiprocessor environments. Memory management services and routines are extensively discussed for both VAX and AXP systems, covering virtual address space, page allocation, and sections. Lastly, it provides guidance on creating user-written system services and implementing site-specific system security policies.