Example of a SYNAD User-Written Exit Routine

The example in Figure 1 demonstrates a user-written exit routine. It is a SYNAD exit routine that examines the FDBK field of the RPL checking for the type of physical error that caused the exit. After the checking, special processing can be performed as necessary. The routine returns to VSAM after printing an appropriate error message on SYSPRINT.

Figure 1. Example of a SYNAD exit routine

ACB1     ACB    EXLST=EXITS
 
EXITS    EXLST  SYNAD=PHYERR
RPL1     RPL    ACB=ACB1,
                MSGAREA=PERRMSG,
                MSGLEN=128
 
PHYERR   USING  *,15             This routine is nonreentrant.
*                                Register 15 is entry address.
         .
         .                       Save caller's register
                                 (1, 13, 14).
         LA     13,SAVE          Point to routine's save area.
         .
         .                       If register 1=address of RPL1,
         .                       then error did not occur for a
                                 CLOSE.
         SHOWCB RPL=RPL1,
                FIELDS=FDBK,
                AREA=ERRCODE,
                LENGTH=4

*                                Show type of physical error.
         .
         .                       Examine error, perform special
         .                       processing.
         PUT    PRTDCB,ERRMSG    Print physical error message.
         .
         .                       Restore caller's registers
         .                       (1, 13, 14).
 
         BR     14               Return to VSAM.
         .
         .
         .
ERRCODE  DC     F'0'             RPL reason code from SHOWCB.
PERRMSG  DS     0XL128           Physical error message.
 
         DS     XL12             Pad for unprintable part.
 
ERRMSG   DS     XL116            Printable format part of message.
         .
         .
         .
PRTDCB   DCB    .....            QSAM DCB.
 
SAVE     DS     18F              SYNAD routine's save area.
 
SAVREG   DS     3F               Save registers 1, 13, 14.