> There are many easy ways to serialize the entry and exiting of an > ENF exit or any other kind of hook so that you can know when it is > safe to free up the CSA it uses and remove the code. One way I have > used in the past is to increment an exit-in-use counter with CS > logic upon entry and decrement it with similar CS logic upon exit. > If the counter is zero, you can free up the CSA control block. Of > course, you must first ensure that the routine is never entered > again before you start the removal process.
The "of course" is the difficult part, if we consider an earlier post which was made by someone who has been the top expert in ENF for over 30 years: "Keep in mind that for an ENF exit that was established via the EXIT= keyword on the ENFREQ ACTION=LISTEN macro, the exit could still be executing or be called even after an ENFREQ ACTION=DELETE returns to you. So be very careful about which storage you think you can safely free after doing an ENFREQ ACTION=DELETE." Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
