Browse Prior Art Database

Table Driven Sequencer for APPC Transaction Programs

IP.com Disclosure Number: IPCOM000108693D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 6 page(s) / 214K

Publishing Venue

IBM

Related People

Gregor, ML: AUTHOR [+3]

Abstract

A program is disclosed that describes how Advanced Program-to-Program Communication (APPC) transaction programs can be implemented using a Table Driven Sequencer approach. An application would develop tables that would represent the protocols and error recovery required. An application would provide a control program to interface with the Table Driven Sequencer as well as other user-defined functions. The Table Driven Sequencer would interpret and manage the execution flow defined by an application's table.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 28% of the total text.

Table Driven Sequencer for APPC Transaction Programs

       A program is disclosed that describes how Advanced
Program-to-Program Communication (APPC) transaction programs can be
implemented using a Table Driven Sequencer approach. An application
would develop tables that would represent the protocols and error
recovery required.  An application would provide a control program to
interface with the Table Driven Sequencer as well as other
user-defined functions.  The Table Driven Sequencer would interpret
and manage the execution flow defined by an application's table.

      The figure illustrates the environment.  User-defined tables,
functions, and control program are all used to interface with the
Table Driven Sequencer.  The Table Driven Sequencer hides the APPC
interface from the application.

      The Table Driven Sequencer is given the name of a control file
which is how an application identifies what tables are to be used.
The control file contains the names of several tables:
      o    verb execution table
      o    data received table
      o    verb retry table
      o    test mode table (optional)

      There exists a relationship between the verb execution table
and the verb retry table.  If a verb executes such that a non-zero
APPC return code is encountered, the verb retry table is indexed
based on verb operation code, primary return code, and secondary
return code to perform an appropriate recovery action.  The
appropriate recovery action is defined by the application.

      There exists a relationship between the verb execution table
and the data received table.  When a receive type verb is encountered
in the verb execution table, the data received table is indexed based
on the data received and status indicators.  If a non-zero return
code is encountered, the verb retry table is indexed based on verb
operation code, primary return code, and secondary return code to
perform an appropriate recovery action.

      There exists a relationship between the verb retry table and
the test mode table.  The test mode table allows the application to
inject APPC errors during development or debug of the transaction
program.  When an APPC error is forced on the execution of a verb,
the Table Driven Sequencer will branch to the verb retry table where
error recovery is performed.  This allows the application to fully
test error recovery code.

      There exists a relationship between the Table Driven Sequencer
and an application.  An application would pass a control block to the
Table Driven Sequencer API which would:
      o    indicate the control file name to be used
      o    indicate the partner to communicate with
      o    indicate the label within the verb execution table to
commence verb execution

      The verb execution table is an ASCII file and is column
oriented.  There exists:

      Column           ...