z/OS Exit Router Information

The out-of-the-box configuration of the exit uses the z/OS exit router to enable the user to specify exit modules at three exit points.

The exit program is EVIPVEX0 and has a pre-built alias of DFSAOE00. The exit points defined are:

  1. DFSAOE00.CMD

    This is invoked whenever DFSAOE00 is called with AOE0FUNC=1 to initialize the routines and also when AOE0FUNC=2 is called with AOE0FLG2=X'80' (command entered at a terminal), X'20' (ICMD command) or X'10' (internal command).

  2. DFSAOE00.MSG

    This is invoked whenever DFSAOE00 is called with AOE0FUNC=1 to initialize the routines and also when AOE0FUNC=2 is called with AOE0FLG2=X'08' (message segment).

  3. DFSAOE00.CMDRESP

    This is invoked whenever DFSAOE00 is called with AOE0FUNC=1 to initialize the routines and also when AOE0FUNC=2 is called with AOE0FLG2=X'40' (command response segment).

Specification of routines to run at each exit point is done via PROGxx members of SYS1.PARMLIB or via the SETPROG EXIT command.

You may enable or disable exits dynamically at any time.

A required definition of EVIPVEX1 is needed to process the exit information for SA z/OS. However, any number of exit routines may be added at any of the points. The z/OS exit router will execute them one after the other. If exit routines are not specified for an exit point, no action will be taken.

The definitions of the required exit points are: 
EXIT ADD EXITNAME(DFSAOE00.MSG) MODNAME(EVIPVEX1) DSNAME(ING.SINGLOAD) STATE(ACTIVE)
EXIT ADD EXITNAME(DFSAOE00.CMD) MODNAME(EVIPVEX1) DSNAME(ING.SINGLOAD) STATE(ACTIVE)
EXIT ADD EXITNAME(DFSAOE00.CMDRESP) MODNAME(EVIPVEX1) DSNAME(ING.SINGLOAD) STATE(ACTIVE)

See z/OS MVS Initialization and Tuning Reference for additional parameters that can be supplied to the EXIT statement.

The SA z/OS exit routines EVIPVEX0 and EVIPVEX1 use the last three words of the storage pointed to by SXPLAWRK. If these values are changed unpredictable results may occur.

The SA z/OS exit router will set AOE0RPLY to 1 if there are no exit routines enabled for an exit and a DFSAOUE0 module is present in the IMS system. This rule applies to each exit point independently. This means that the user can disable an exit point and still have their DFSAOUE0 module invoked. In addition if the exit point invoked is EVIPVEX1 as specified, see Using the SA z/OS Exit without the z/OS Exit Router for details on invoking DFSAOUE0. Note that it is possible using the z/OS exit router to invoke DFSAOUE0 for all three exit points. This can be achieved by the default definition that does not define an exit point for DFSAOE00.CMDRESP or by disabling this exit point.