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CICS FREEMAIN64 - 64-bit Memory Deallocation

CICS FREEMAIN64 provides 64-bit memory deallocation capabilities for programs and transactions. It enables programs to free allocated 64-bit memory, manage 64-bit memory cleanup, and handle 64-bit memory deallocation in CICS environments.

What is CICS FREEMAIN64?

CICS FREEMAIN64 is a command that allows programs to deallocate 64-bit memory in the system. It provides 64-bit memory deallocation capabilities, 64-bit memory cleanup, and 64-bit memory management for CICS applications.

Command Syntax

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EXEC CICS FREEMAIN64
    [DATA(data-area)]
    [LENGTH(data-length)]
    [RESP(response-code)]
END-EXEC

Parameters

Optional Parameters

  • DATA(data-area) - 64-bit data area to free
  • LENGTH(data-length) - Length of 64-bit data to free
  • RESP(response-code) - Response code variable

64-bit Memory Types

64-bit Main Storage

64-bit main storage memory types

  • • 64-bit MAIN STORAGE - 64-bit main storage memory
  • • 64-bit AUXILIARY STORAGE - 64-bit auxiliary storage memory
  • • 64-bit VIRTUAL STORAGE - 64-bit virtual storage memory
  • • 64-bit SHARED STORAGE - 64-bit shared storage memory

64-bit Memory Areas

64-bit memory area types

  • • 64-bit WORKING STORAGE - 64-bit working storage memory
  • • 64-bit LINKAGE SECTION - 64-bit linkage section memory
  • • 64-bit COMMUNICATION AREA - 64-bit communication area memory
  • • 64-bit BUFFER AREA - 64-bit buffer area memory

64-bit Dynamic Memory

64-bit dynamic memory types

  • • 64-bit DYNAMIC STORAGE - 64-bit dynamic storage memory
  • • 64-bit HEAP STORAGE - 64-bit heap storage memory
  • • 64-bit STACK STORAGE - 64-bit stack storage memory
  • • 64-bit TEMPORARY STORAGE - 64-bit temporary storage memory

64-bit System Memory

64-bit system memory types

  • • 64-bit SYSTEM STORAGE - 64-bit system storage memory
  • • 64-bit USER STORAGE - 64-bit user storage memory
  • • 64-bit PROTECTED STORAGE - 64-bit protected storage memory
  • • 64-bit COMMON STORAGE - 64-bit common storage memory

Programming Examples

Basic 64-bit Memory Deallocation

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. FREEMAIN64.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  DATA-AREA PIC X(100).
       01  DATA-LENGTH PIC S9(4) COMP VALUE 100.
       01  RESPONSE-CODE PIC S9(8) COMP.
       
       PROCEDURE DIVISION.
           DISPLAY 'Freeing 64-bit memory'
           DISPLAY 'Data length: ' DATA-LENGTH
           
           EXEC CICS FREEMAIN64
               DATA(DATA-AREA)
               LENGTH(DATA-LENGTH)
               RESP(RESPONSE-CODE)
           END-EXEC
           
           IF RESPONSE-CODE = DFHRESP(NORMAL)
               DISPLAY '64-bit memory freed successfully'
           ELSE
               DISPLAY '64-bit memory free failed'
           END-IF
           
           EXEC CICS RETURN END-EXEC.

Advanced 64-bit Memory Management

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. FREEMAIN642.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  DATA-AREA PIC X(100).
       01  DATA-LENGTH PIC S9(4) COMP VALUE 100.
       01  RESPONSE-CODE PIC S9(8) COMP.
       01  FREE-COUNT PIC S9(2) COMP VALUE 0.
       01  MAX-FREES PIC S9(2) COMP VALUE 3.
       01  MEMORY-STATUS PIC X(1).
       01  MEMORY-LIST.
           05  MEMORY-ITEM OCCURS 3 TIMES.
               10  MEMORY-ID PIC X(8).
               10  MEMORY-SIZE PIC S9(4) COMP.
               10  MEMORY-STATUS PIC X(1).
       
       PROCEDURE DIVISION.
           PERFORM INITIALIZE-64BIT-MEMORY
           PERFORM FREE-MULTIPLE-64BIT-MEMORY
           
           EXEC CICS RETURN END-EXEC.
       
       INITIALIZE-64BIT-MEMORY.
           MOVE 'MEM001' TO MEMORY-ID(1)
           MOVE 100 TO MEMORY-SIZE(1)
           MOVE 'MEM002' TO MEMORY-ID(2)
           MOVE 200 TO MEMORY-SIZE(2)
           MOVE 'MEM003' TO MEMORY-ID(3)
           MOVE 300 TO MEMORY-SIZE(3).
       
       FREE-MULTIPLE-64BIT-MEMORY.
           PERFORM VARYING FREE-COUNT FROM 1 BY 1
               UNTIL FREE-COUNT > MAX-FREES
               
               MOVE MEMORY-SIZE(FREE-COUNT) TO DATA-LENGTH
               PERFORM FREE-SINGLE-64BIT-MEMORY
               
               IF RESPONSE-CODE = DFHRESP(NORMAL)
                   MOVE 'F' TO MEMORY-STATUS(FREE-COUNT)
                   DISPLAY '64-bit memory ' FREE-COUNT ' freed successfully'
               ELSE
                   MOVE 'E' TO MEMORY-STATUS(FREE-COUNT)
                   DISPLAY '64-bit memory ' FREE-COUNT ' free failed'
               END-IF
           END-PERFORM.
       
       FREE-SINGLE-64BIT-MEMORY.
           EXEC CICS FREEMAIN64
               DATA(DATA-AREA)
               LENGTH(DATA-LENGTH)
               RESP(RESPONSE-CODE)
           END-EXEC.

Error Handling with 64-bit Memory Deallocation

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       IDENTIFICATION DIVISION.
       PROGRAM-ID. FREEMAIN643.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  DATA-AREA PIC X(100).
       01  DATA-LENGTH PIC S9(4) COMP VALUE 100.
       01  RESPONSE-CODE PIC S9(8) COMP.
       01  RETRY-COUNT PIC S9(2) COMP VALUE 0.
       01  MAX-RETRIES PIC S9(2) COMP VALUE 3.
       01  MEMORY-FREE-SUCCESSFUL PIC X(1) VALUE 'N'.
       
       PROCEDURE DIVISION.
           PERFORM FREE-64BIT-MEMORY-WITH-RETRY
           
           EXEC CICS RETURN END-EXEC.
       
       FREE-64BIT-MEMORY-WITH-RETRY.
           PERFORM FREE-64BIT-MEMORY
           
           IF RESPONSE-CODE NOT = DFHRESP(NORMAL)
               AND RETRY-COUNT < MAX-RETRIES
               ADD 1 TO RETRY-COUNT
               DISPLAY 'Retry ' RETRY-COUNT ' 64-bit memory free operation'
               PERFORM FREE-64BIT-MEMORY-WITH-RETRY
           END-IF.
       
       FREE-64BIT-MEMORY.
           EXEC CICS FREEMAIN64
               DATA(DATA-AREA)
               LENGTH(DATA-LENGTH)
               RESP(RESPONSE-CODE)
           END-EXEC
           
           EVALUATE RESPONSE-CODE
               WHEN DFHRESP(NORMAL)
                   MOVE 'Y' TO MEMORY-FREE-SUCCESSFUL
                   DISPLAY '64-bit memory free operation successful'
               WHEN DFHRESP(NOTAUTH)
                   DISPLAY 'Not authorized to free 64-bit memory'
               WHEN DFHRESP(INVREQ)
                   DISPLAY 'Invalid 64-bit memory free request'
               WHEN DFHRESP(MEMORYERR)
                   DISPLAY '64-bit memory free operation error'
               WHEN DFHRESP(MEMORYNOTFOUND)
                   DISPLAY '64-bit memory not found'
               WHEN DFHRESP(MEMORYINUSE)
                   DISPLAY '64-bit memory is in use'
               WHEN OTHER
                   DISPLAY 'Unexpected 64-bit memory free error'
           END-EVALUATE.

64-bit Memory Management

64-bit Memory Deallocation

  • • 64-bit Memory Free - Free allocated 64-bit memory
  • • 64-bit Memory Cleanup - Clean up 64-bit memory state
  • • 64-bit Memory Validation - Validate 64-bit memory state
  • • 64-bit Memory Monitoring - Monitor 64-bit memory status

64-bit Memory Lifecycle

  • • 64-bit Memory Allocation - Allocate 64-bit memory
  • • 64-bit Memory Usage - Use allocated 64-bit memory
  • • 64-bit Memory Deallocation - Deallocate 64-bit memory
  • • 64-bit Memory Cleanup - Clean up 64-bit memory

64-bit Memory Monitoring

  • • 64-bit Memory Tracking - Track 64-bit memory usage
  • • 64-bit Memory Auditing - Audit 64-bit memory operations
  • • 64-bit Memory Reporting - Report 64-bit memory status
  • • 64-bit Memory Analysis - Analyze 64-bit memory patterns

64-bit Error Recovery

  • • 64-bit Error Detection - Detect 64-bit memory errors
  • • 64-bit Error Recovery - Recover from 64-bit memory errors
  • • 64-bit Retry Mechanisms - Implement 64-bit retry logic
  • • 64-bit Fallback Procedures - Use 64-bit fallback procedures

Error Handling

Common Response Codes

  • DFHRESP(NORMAL) - 64-bit memory free operation successful
  • DFHRESP(NOTAUTH) - Not authorized to free 64-bit memory
  • DFHRESP(INVREQ) - Invalid 64-bit memory free request
  • DFHRESP(MEMORYERR) - 64-bit memory free operation error
  • DFHRESP(MEMORYNOTFOUND) - 64-bit memory not found
  • DFHRESP(MEMORYINUSE) - 64-bit memory is in use

Performance Considerations

64-bit Memory Efficiency

  • • Optimize 64-bit memory operations - Use efficient 64-bit memory handling
  • • Minimize 64-bit memory overhead - Reduce 64-bit memory processing overhead
  • • Use 64-bit memory pooling - Implement 64-bit memory pooling
  • • Monitor 64-bit memory frequency - Track 64-bit memory free patterns

System Impact

  • • Monitor system impact - Track how 64-bit memory free affects the system
  • • Optimize 64-bit memory handling - Ensure efficient 64-bit memory processing
  • • Manage 64-bit memory usage - Monitor 64-bit memory consumption
  • • Track performance metrics - Monitor 64-bit memory handling performance

Best Practices

64-bit Memory Deallocation Best Practices

  • • Free 64-bit memory as soon as it is no longer needed
  • • Implement proper error handling for 64-bit memory operations
  • • Validate 64-bit memory state before freeing
  • • Use appropriate 64-bit memory management techniques
  • • Monitor 64-bit memory deallocation activities and performance
  • • Maintain 64-bit memory deallocation audit trails
  • • Handle 64-bit memory deallocation errors gracefully

Explain It Like I'm 5 Years Old

Think of CICS FREEMAIN64 like putting away your big memory toys:

  • • Finished Playing: "You finished playing with your big memory toys" - 64-bit memory no longer needed
  • • Put Away: "Put your big memory toys away" - Free 64-bit memory
  • • Clean Up: "Clean up your big memory toy area" - 64-bit memory cleanup
  • • Room Clean: "Your big memory toy area is clean now" - 64-bit memory freed
  • • Keep Clean: "Keep your big memory toy area clean" - 64-bit memory management

Exercises

Exercise 1: Basic 64-bit Memory Deallocation

Create a program that frees basic 64-bit memory.

Exercise 2: Advanced 64-bit Memory Management

Write a program that manages multiple 64-bit memory deallocations.

Exercise 3: Error Handling

Implement comprehensive error handling for 64-bit memory deallocation failures.

Related Concepts

64-bit Memory Management

Managing 64-bit system memory

64-bit Memory Deallocation

Deallocating 64-bit memory

64-bit Memory Monitoring

Monitoring 64-bit memory usage

64-bit Memory Cleanup

Cleaning up 64-bit memory

Error Handling

Managing 64-bit memory errors