Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Open Close Parallel Processing

IP.com Disclosure Number: IPCOM000075516D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 3 page(s) / 31K

Publishing Venue

IBM

Related People

Radencic, GA: AUTHOR

Abstract

The OPEN macro allows a user to specify up to sixteen (16) files, which may have varied characteristics and device types. A commonly used technique, known as serial processing, is to process-files sequentially as specified on the OPEN macro instruction. With this method, transient phases are loaded more than once if files with similar characteristics are given.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Open Close Parallel Processing

The OPEN macro allows a user to specify up to sixteen (16) files, which may have varied characteristics and device types. A commonly used technique, known as serial processing, is to process-files sequentially as specified on the OPEN macro instruction. With this method, transient phases are loaded more than once if files with similar characteristics are given.

Parallel processing, as illustrated in the flow diagram of Fig. 1, eliminates this built-in redundancy and provides a significant average time reduction in OPEN processing. This reduction is attained because no single phase is loaded more than once on a single OPEN, regardless of the number of characteristics of the files on the OPEN list.

Parallel processing requires an eight-byte where-to-go (WTC) table (Fig. 2) within the define-the-file-block (DTFB). An eight-byte field initialized by the last OPEN phase was chosen for use as the WTG. This means that no permanent table space is required for parallel processing. This eight-byte WTG is divided into two four-byte fields called PATH1 and PATH2.

Parallel processing is driven by the last two characters of the phase name. These characters are always unique, since the first six characters are defined by standards. The WTC table contains the two four-byte fields known as PATH1 and PATH2. PATH1 always contains the two-byte phase name suffix of the next phase needed for the file. This suffix is right justified and padded to the left with binary zeros. PATH1 is initialized by the first phase or MONITOR and reinitialized by each phase which processes that file.

When a phase is loaded, it must process all files with a PATH1 indicating its respective two-byte suffix. When a file is processed, PATH1 is reset to the suffix of the next phase needed for that file. The processing of a phase is completed when no file on the OPEN list contains a PATH1 with its respective suffix. At this point, it must determine which phase is needed next for that OPEN list.

To determine the next phases needed, the WTC tables are scanned for all files on the...