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CICS ISSUE WAIT - Issue Wait

CICS ISSUE WAIT issues a wait operation, enabling wait management and output processing in CICS environments. It provides efficient wait capabilities for CICS applications.

What is CICS ISSUE WAIT?

CICS ISSUE WAIT issues a wait operation, enabling wait management and output processing. It provides efficient wait capabilities, allowing applications to issue wait operations.

Command Syntax

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EXEC CICS ISSUE WAIT
    [RESP(response-code)]
    [RESP2(response-code-2)]
END-EXEC.

Parameters Explained

RESP Parameters

Response codes returned by the command:

  • RESP: Primary response code - indicates the success or failure of the wait operation
  • RESP2: Secondary response code - provides additional error information when RESP indicates failure
  • Always check these codes for command success before proceeding with data processing
  • Handle command failures appropriately to prevent application errors

Wait Types

1. Basic Waits

  • Basic waits: Standard wait operations that handle simple synchronization without special formatting
  • Mapped waits: Wait operations that use predefined field mappings to structure wait data
  • Unmapped waits: Raw wait operations that handle unstructured synchronization without predefined field mappings
  • Custom waits: Specialized wait operations designed for specific application requirements

2. Advanced Waits

  • Advanced waits: Complex wait operations that handle sophisticated synchronization processing and validation
  • Secure waits: Wait operations that include encryption and security features for sensitive synchronization
  • Encrypted waits: Wait operations that automatically encrypt wait data
  • Compressed waits: Wait operations that handle compressed synchronization streams and automatically compress wait data

3. Specialized Waits

  • Specialized waits: Wait operations tailored for specific protocols or communication methods
  • High-performance waits: Optimized wait operations designed for maximum throughput and efficiency
  • Low-latency waits: Wait operations optimized for minimal delay and real-time processing requirements
  • High-throughput waits: Wait operations designed to handle large volumes of synchronization efficiently

Implementation Example

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WORKING-STORAGE SECTION.
01 WS-RESPONSE            PIC S9(8) COMP.
01 WS-RESPONSE2           PIC S9(8) COMP.
 
PROCEDURE DIVISION.
    * Issue wait
    EXEC CICS ISSUE WAIT
        RESP(WS-RESPONSE)
        RESP2(WS-RESPONSE2)
    END-EXEC.
    
    IF WS-RESPONSE NOT EQUAL DFHRESP(NORMAL)
        EXEC CICS WRITE OPERATOR
            TEXT('ISSUE WAIT command failed')
        END-EXEC
        EXEC CICS RETURN END-EXEC
    END-IF.
    
    * Wait issued successfully
    * Continue processing

Wait Processing

1. Wait Preparation

Wait preparation includes:

  • Wait validation - ensuring the wait operation is properly configured and authorized
  • Wait formatting - preparing data structures and buffers for wait data
  • Wait encoding - setting up proper character encoding and data transformation
  • Wait processing - initializing the wait operation and preparing for synchronization

2. Wait Transmission

Wait transmission includes:

  • Wait routing - directing wait data to the appropriate processing location
  • Wait delivery - ensuring wait data reaches the correct destination within the application
  • Transmission confirmation - verifying that wait was completed successfully
  • Error handling - managing transmission failures and implementing retry mechanisms

3. Output Management

Output management includes:

  • User management - handling user sessions and maintaining connection state
  • Output formatting - structuring wait data for presentation or further processing
  • User experience - ensuring smooth data flow and responsive application behavior
  • Performance optimization - maximizing wait efficiency and minimizing resource usage

Common Response Codes

Success Response Codes

  • NORMAL (0): Wait issued successfully - synchronization was completed without errors
  • WAIT (4): Wait issued - operation completed with wait-specific status

Error Response Codes

  • INVREQ (16): Invalid request - the wait operation parameters are incorrect or unauthorized
  • NOTFND (20): Resource not found - the specified wait resource does not exist
  • LENGERR (22): Length error - the wait data length exceeds expected limits
  • WAIT (24): Wait error - a wait-specific error occurred during the operation

Best Practices

1. Wait Preparation

  • Prepare wait appropriately - ensure all necessary resources and configurations are in place
  • Validate wait content - verify that wait data meets expected format and quality standards
  • Handle different wait types - implement flexible processing to accommodate various synchronization formats
  • Ensure wait integrity - maintain data consistency and prevent corruption during synchronization

2. Error Handling

  • Check all response codes - always examine both RESP and RESP2 for complete error information
  • Handle wait failures - implement appropriate recovery mechanisms for failed wait operations
  • Implement retry logic - provide automatic retry capabilities for transient failures
  • Log error conditions - maintain detailed logs for troubleshooting and monitoring purposes

3. Performance Optimization

  • Minimize wait operations - reduce unnecessary wait calls to improve overall performance
  • Use efficient wait formats - choose appropriate data formats to minimize processing overhead
  • Optimize user updates - streamline user interface updates to reduce response time
  • Manage user resources - efficiently allocate and manage system resources for wait operations

Explain It Like I'm 5 Years Old

Imagine you're waiting for your turn:

When you want to wait for your turn, you stand in line and wait until it's your turn. If you wait patiently, you get your turn. If you don't wait, you have to start over.

CICS ISSUE WAIT is like waiting for your turn. The computer program waits in line until it's its turn. If it waits patiently, it gets its turn. If it doesn't wait, it has to start over.

Just like you wait for your turn, the computer program waits for its turn!

Exercises

Exercise 1: Wait Issuance

Write a CICS ISSUE WAIT command to issue a wait operation.

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EXEC CICS ISSUE WAIT
    RESP(WS-RESPONSE)
    RESP2(WS-RESPONSE2)
END-EXEC.

Exercise 2: Wait Processing

How would you implement comprehensive wait processing that handles different wait types and requirements?

Answer: Identify different wait types and appropriate handling, implement wait validation and encoding, handle different wait types and capabilities, implement proper error handling for wait failures, optimize wait operations for performance, and maintain wait integrity throughout the process.

Quiz

Question 1

What is the primary purpose of CICS ISSUE WAIT?

Answer: B) To issue a wait operation

Question 2

Which parameter specifies the response code?

Answer: A) RESP

Related Concepts

CICS Wait Processing

Wait processing and output in CICS

CICS User Management

User management and user interaction in CICS

CICS Output Processing

Output processing and wait display in CICS