gtpa2m09Application Programming

Some Fundamental Definitions

A System/370 online computing facility or central processing complex (CPC) is defined as set of central processing units (CPUs) that are packaged together to share a common main storage. The term used in TPF documentation for the set of CPUs in a CPC is instruction-stream engines or I-streams. A CPC used in a batch data processing environment normally follows a repetitive cycle of events that can be planned and timed in detail by programmers.

In a real-time TPF environment, this is seldom the case, because the sequence of operations is unpredictable. The volume and variety of messages received is such that several messages may be in the CPC at any one time. The TPF control program is used to schedule work, allocate storage, and assess priorities continuously. It permits message processing on an I-stream and component-sharing basis to maximize use of the various system resources. These resources include main and file storage, input/output components, terminal equipment, and the processing performed by each I-stream.

Language Structures and Case Guidelines

Throughout this publication there are references to C language and assembly language structures and symbols.

Note:
The C language structures are in lowercase and the assembly language structures are in uppercase. This is important because often the only difference between the C language structure and the assembly language structure is the case of the name. When this occurs, we provide only the lowercase name (C language). The assembly language equivalent is always just the uppercase spelling. When there are more differences than just the case of the name, both the C language and assembly language versions are provided.

See the glossary in TPF Library Guide for definitions of additional TPF system and C language terms.