IBM Mainframe Discussion List <[email protected]> wrote on 09/20/2006 07:59:55 PM:
> > -----Original Message----- > > From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On > > Behalf Of Jim Mulder > > Sent: Wednesday, September 20, 2006 3:40 PM > > To: [email protected] > > Subject: Re: The ASCRE initialization routine > > > > IBM Mainframe Discussion List <[email protected]> wrote on 09/20/2006 > > 11:21:40 AM: > > > /snip/ > > Since the region subpools are not freed, any region subpools used > > during the initialization routine will continue to be key 0, when they > > would usually be key 8 or the PPT key. So, for example, if you LOAD > > a non-reentrant module during the initialization routine, subpool 251 > > will be created as a key 0 subpool. Then later when your jobstep task > > gets attached, since the region was not freed, subpool 251 will still > > exist as a key 0 subpool. Subsequent LOADs of non-reentrant modules > > into subpool 251 will be into key 0 storage (and fetch protected), > > so you won't be able to execute them unless you are running key 0. > > Also, the REGION/IEFUSI limits will not be honored. > > > > Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY > > I would have guessed that attaching the job step task (EXEC PGM=name) > would specify on the ATTACHX macro no shared subpools. Doesn't make > sense for a job step task to share any subpools with the higher job > step tasks. > I did insufficient research before making my previous post on this topic (I'll blame that on trying to multitask programming and parenting). Upon further code review, it looks like only subpool 0 is shared between the initiator and the jobstep task, so that the unexpected key weirdness I spoke of should apply only to subpool 0 when the ASCRE initialization routine (or an exit) uses subpool 0 (or 240/250) and KEEPRGN is specified. This is discussed in APAR OW40095. As to why subpool 0 is shared, I haven't been able to think of a reason. I don't know of anything that the initiator obtains in subpool 0 that the jobstep task can free (unless there was a time when programs would free the the EXEC PARM= parameter storage after processing it), or anything that the jobstep task would obtain from subpool 0 that needs to survive the termination of the jobstep task. 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: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
