Overview of IMS Connect exit routines

IMS provides a variety of exit routines to support IMS Connect.

IMS Connect exit routines fall into two general categories:
  • User message exit routines that manage the messages to and from the various types of IMS Connect TCP/IP clients
  • Exit routines that provide general functionality, such as security and routing
The IMS Connect user message exit routines, which are used only with clients connecting to IMS TM, include:
  • HWSSMPL0 and HWSSMPL1 user message exits, for user-written IMS Connect client applications
  • HWSJAVA0 user message exit, for the IMS TM Resource Adapter
  • HWSSOAP1 user message exit, for the IMS Enterprise Suite SOAP Gateway
  • HWSCSLO0 and HWSCSLO1 user message exits, for the OM command clients

All of the IMS Connect client user message exits allow you to call the z/OS® TCP/IP IMS Listener security exit routine (IMSLSECX), issue the RACF® function in these user message exit routines, or use the IMS Connect user RACF function.

Attention: Do not issue any z/OS calls in the user message exit that result in an MVS WAIT. If you modify the user message exit and add code that results in an MVS WAIT, all work on the TCP/IP PORT will halt until the WAIT has been posted. The user message exits cannot be modified to free any storage passed to the exit, and IMS Connect will not free any storage obtained by the user message exit when the exit returns to IMS Connect. All storage obtained by IMS Connect must be released by IMS Connect and cannot be freed by the User Message Exit without causing failures.

The exit routines that provide general functionality to IMS Connect include:
  • The sample IMS Connect Destination Resolution exit routine (HWSYDRU0), which is a modified version of the OTMA Destination Resolution exit routine (DFSYDRU0)
  • IMS Connect User Initialization exit routine (HWSUINIT)
  • z/OS TCP/IP IMS Listener security exit routine (IMSLSECX)
  • IMS Connect Password Change exit routine (HWSPWCH0)
  • IMS Connect Event Recorder exit routine (HWSTECL0)
  • IMS Connect Port Message Edit exit routine for TCP/IP clients
  • IMS Connect DB Routing user exit routine (HWSROUT0)
  • IMS Connect DB Security user exit routine (HWSAUTH0)

IMS Connect always loads HWSUINIT and HWSJAVA0, but HWSSMPL0 and HWSSMPL1 are optional and are loaded only if you include them with the TCPIP statement in the IMS Connect member of the IMS.PROCLIB data set (HWSCFGxx). These four exit routines are provided as load modules for ease of use. Source code is also provided so that you can modify the exit routines for your installation.

This topic contains Product-sensitive Programming Interface information.