Exit replacement function (function code X'09')

This function indicates that the current session management exit routine is going to be replaced with a new copy of the session management exit routine through a MODIFY EXIT,OPTION=REPL command. This function is processed immediately before the exit is replaced. The replacement will not interrupt VTAM® processing. If a replace command fails, the exit for which the command was issued is inactive. For more information about replacing exits, see Replacing VTAM exit routines. For more information about the command, see z/OS Communications Server: SNA Operation.

Table 1 shows the exit replacement function parameter list pointed to by register 1. The parameters are described in Parameter descriptions.

Table 1. Exit replacement function parameter list
Dec (Hex) Offset	Size (Bytes)	Description
0 (0)	4	Address of environment vectors
4 (4)	4	Address of function code and related session information code
8 (8)	4	Address of user data field
16 (10)	4	Address of a parameter string if you specify a value for the PARMS operand on the MODIFY EXIT command. The parameter string is in the form of a 2-byte length field followed by the actual character data. If you do not specify a value, this pointer will be zero.
72 (48)	4	Address of VTAM exit services parameter list