PL/I Advanced Demo Session › Option 04: How to Detect a Storage Violation › Prevent a Storage Violation

Prevent a Storage Violation

The next screen is a breakpoint display screen. CA InterTest for CICS halted the demo program at an automatic breakpoint. CA InterTest for CICS prevented the storage violation that would have resulted if the highlighted MOVE statement had been executed. CA InterTest for CICS has also inserted an A next to the statement to indicate an automatic breakpoint.

CA InterTest for CICS Release 9.1.00   - PROTSYM FILE  ABEND DETECTED BREAKPOINT        
COMMAND ===>                                                                   
Program= PLIDEMO  Option #       Stmt #                             Margin= 01 
                                        Search=                                
-------------------------------------------------------------------------------
 _____ CKPTNAME                        | PROTCPF                               
 _____ NUP_AREA                        |          THIS IS NOT A NAME  PRIME THE
 _____ REC_LEN                         | +00681.                               
 _____ INPUT_REC_2                     | .........................             
 _____ OUTPUT_REC_2                    | .........................             
---------+---------------------------------------------------------------------
 _  1431.1     1  1          END;                                              
 _  1432.1     1             OUTPUT_REC_2     =  INPUT_REC_2;                  
 A   ==>.1     1             INPUT_REC_2      =  OUTPUT_REC_2;      ==>      
     ==> an attempt to change an area that does not belong to this task.     
     ==> Possible system damage has been prevented.                          
     ==>                                                                     
     ==>      Press PF1 for a detailed description.                          
     ==>                                                                       
                                                                               
 _  1434.1     1             GOTO SENDMP00;                                    
 _  1435.1     1      LOOPRTN:                                                 
 _  1436.1                   DO I = 1 TO 50;                                   
 _  1437.1                      /* EXEC CICS ASKTIME */

Preventing storage violations is one of the most important reasons to monitor programs. Storage violations are notorious CICS errors that can:

• Bring down your CICS system.
• Cause a program to produce erroneous data.
• Cause one program to corrupt the data of another program. In this case, tracking down the problem without CA InterTest for CICS is almost impossible because the error is not in the affected program.

By stopping the program before the storage violation can occur, CA InterTest for CICS protects your system and helps you diagnose and correct the error.

In this example, the statement that would have caused the storage violation is:

INPUT_REC_2 = OUTPUT_REC_2

This statement moves data from OUTPUT_REC_2 TO INPUT_REC_2. The program may not own the area of storage defined as INPUT_REC_2, so the program cannot move data to that field.