Comparing the two methods of linking CEEBXITA

You can link in the user exit CEEBXITA in the following ways:

• Link it into the application program.

  Advantage

  The user exit affects only the application program being debugged. This means you can control when z/OS® Debugger is started for the application program. You might also not need to make any changes to your JCL to start z/OS Debugger.

  Disadvantage

  You must remember to remove the user exit for production or, if it isn't part of your normal build process, you must remember to relink it to the application program.

• Link it into a private copy of a Language Environment® runtime load module (CEEBINIT, CEEPIPI, or both)

  Advantage

  You do not have to change your application program to use the user exit. In addition, you do not have to link edit extra modules into your application program.

  Disadvantage

  You need to take extra steps in preparing and maintaining your runtime environment:

  • Make a private copy of one or more Language Environment runtime routines
  • Only for the modules you might debug, customize your runtime environment to place the private copies in front of the system Language Environment modules in CEE.SCEERUN in the load module search path
  • When you apply maintenance to Language Environment, you might need to relink the routines.
  • When you upgrade to a new version of Language Environment, you must relink the routines.

If you link the user exit into the application program and into a private copy of a Language Environment runtime load module, which is in the load module search path of your application execution, the copy of the user exit in the application load module is used.