This section contains a more detailed description of the user shell processes. Besides providing an overall understanding, this section could be useful in tracking down an error condition.
There are three major user shell control processes:
An unexpected return code during any of these processes causes message AEG1112 to be sent to the system operator, a dump to be taken, and a fatal error condition to be set.
User application initialization builds the background environment common to all CICS sessions. This includes:
In more detail, the initialization process consists of the following steps:
When all shell startup processes are complete, the terminal operator (if this is an interactive job) is sent a message indicating that the shell is initialized and operational. The CICS user can then enter transactions.
After initialization, the shell coordinates the repetitive process of event scheduling, (ATI, IC START, ISC, or terminal input) scheduling and task termination with syncpoint and rollback processing.
Note: The shell can receive work from a data queue, display file, or ICF file.
The runtime processing of the shell can be described in the following steps:
Shutdown processing can be initiated by any of the following:
Note: A shell will respond to an external end request, such as a message sent by the control region during shutdown processing, only when it next returns to a dequeue state. If the shell is processing a conversational task or is running in a held OS/400 job, shutdown will not occur immediately.
Shutdown provides for a reversal of the initialization process. A controlled shell shutdown consists of the following steps:
If you want the terminal shell to shut down when either the terminal is switched off or the session is ended, the job description for the job running in the terminal shell should have the device recovery action (DEVRCYACN) parameter set to *ENDJOB. Some directly-connected terminals do not require this parameter to be set, but setting it does not change the shell execution. If the shell is to be run in a passthru session, the DEVRCYACN parameter must be set in the job description for the job that issues the STRPASTHR command.
If CESF LOGOFF (supplied transaction) is used,the shell logs the user off from CICS and issues the OS/400 SIGNOFF CL command.
If termination is caused by a CICS shutdown, the user is informed of the involuntary shutdown.Control is returned to OS/400 facilities.
Nonterminal users are shut down by internal data queue commands or ISC conversation link termination.
IBM - AS/400 Related Interview Questions
|IBM - RPG Interview Questions||IBM - VSAM Interview Questions|
|IBM Cognos Interview Questions||IBM DB2 Interview Questions|
|System Administration Interview Questions||IBM AIX Interview Questions|
|SQL Interview Questions||AS400 Interview Questions|
|IBM BPM Interview Questions||Synopsys Interview Questions|
|Rpgle Interview Questions|
Ibm - As/400 Tutorial
Introducing Cics® For Iseries™
Defining A Basic Control Region
Security Requirements For Cics/400
Defining Your Own Control Region
Administering The Control Region
Administering A Cics/400 Shell
Defining Resources-reference Information
Autoinstall For Terminal Definitions
Introduction To Cics/400-supplied Transactions
Cemt—cics Master Terminal Transaction
All rights reserved © 2018 Wisdom IT Services India Pvt. Ltd
Wisdomjobs.com is one of the best job search sites in India.