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CICS FREE CHILD - Free Child Process

CICS FREE CHILD frees a child process, enabling child process management and output processing in CICS environments. It provides efficient child process freeing capabilities for CICS applications.

What is CICS FREE CHILD?

CICS FREE CHILD frees a child process, enabling child process management and output processing. It provides efficient child process freeing capabilities, allowing applications to free a child process.

Command Syntax

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EXEC CICS FREE CHILD
    CHILD(child-id)
    [RESP(response-code)]
    [RESP2(response-code-2)]
END-EXEC.

Parameters Explained

CHILD Parameter

Specifies the child process to free:

  • Must be a valid child process ID
  • Identifies specific child
  • Required for all FREE CHILD operations
  • Must be active child process

RESP Parameters

Response codes returned by the command:

  • RESP: Primary response code
  • RESP2: Secondary response code
  • Always check these codes for command success
  • Handle command failures appropriately

Child Process Types

1. Basic Child Processes

  • Basic child processes: Basic child processes
  • Mapped child processes: Mapped child processes
  • Unmapped child processes: Unmapped child processes
  • Custom child processes: Custom child processes

2. Advanced Child Processes

  • Advanced child processes: Advanced child processes
  • Secure child processes: Secure child processes
  • Encrypted child processes: Encrypted child processes
  • Compressed child processes: Compressed child processes

3. Specialized Child Processes

  • Specialized child processes: Specialized child processes
  • High-performance child processes: High-performance child processes
  • Low-latency child processes: Low-latency child processes
  • High-throughput child processes: High-throughput child processes

Implementation Example

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WORKING-STORAGE SECTION.
01 WS-RESPONSE            PIC S9(8) COMP.
01 WS-RESPONSE2           PIC S9(8) COMP.
01 WS-CHILD-ID            PIC X(8) VALUE 'CHILD001'.
 
PROCEDURE DIVISION.
    * Free specific child process
    EXEC CICS FREE CHILD
        CHILD(WS-CHILD-ID)
        RESP(WS-RESPONSE)
        RESP2(WS-RESPONSE2)
    END-EXEC.
    
    IF WS-RESPONSE NOT EQUAL DFHRESP(NORMAL)
        EXEC CICS WRITE OPERATOR
            TEXT('FREE CHILD command failed')
        END-EXEC
        EXEC CICS RETURN END-EXEC
    END-IF.
    
    * Child process freed successfully
    * Continue processing

Child Process Processing

1. Child Process Preparation

Child process preparation includes:

  • Child process validation
  • Child process formatting
  • Child process encoding
  • Child process processing

2. Child Process Transmission

Child process transmission includes:

  • Child process routing
  • Child process delivery
  • Transmission confirmation
  • Error handling

3. Output Management

Output management includes:

  • Process management
  • Output formatting
  • User experience
  • Performance optimization

Common Response Codes

Success Response Codes

  • NORMAL (0): Child process freed successfully
  • FREE (4): Child process freed

Error Response Codes

  • INVREQ (16): Invalid request
  • NOTFND (20): Child process not found
  • LENGERR (22): Length error
  • FREE (24): Free error

Best Practices

1. Child Process Preparation

  • Prepare child process appropriately
  • Validate child process content
  • Handle different child process types
  • Ensure child process integrity

2. Error Handling

  • Check all response codes
  • Handle free failures
  • Implement retry logic
  • Log error conditions

3. Performance Optimization

  • Minimize child process freeing
  • Use efficient child process formats
  • Optimize process updates
  • Manage process resources

Explain It Like I'm 5 Years Old

Imagine you're putting away a toy:

When you're done playing with a toy, you put it away in its proper place. You make sure the toy is clean and organized, and then you put it back where it belongs so it's ready for next time.

CICS FREE CHILD is like putting away a toy. The computer program takes a child process that it's done using, cleans it up, and puts it back where it belongs so it's ready for next time.

Just like you put away your toys when you're done playing, the computer program puts away child processes when it's done using them!

Exercises

Exercise 1: Child Process Freeing

Write a CICS FREE CHILD command to free a specific child process.

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EXEC CICS FREE CHILD
    CHILD(WS-CHILD-ID)
    RESP(WS-RESPONSE)
    RESP2(WS-RESPONSE2)
END-EXEC.

Exercise 2: Child Process Processing

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

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

Quiz

Question 1

What is the primary purpose of CICS FREE CHILD?

Answer: B) To free a child process

Question 2

Which parameter specifies the child process to free?

Answer: A) CHILD

Related Concepts

CICS Child Process Processing

Child process processing and output in CICS

CICS Process Management

Process management and user interaction in CICS

CICS Output Processing

Output processing and child process display in CICS