> "ordinarily expected". Is this a retreat from the earlier well-known > rule (cited by Peter) that a RENT program was allowed to modify its > own code given proper serialization?
I read it as saying that it's permitted but bad form, and I agree. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@listserv.ua.edu> on behalf of Paul Gilmartin <0000000433f07816-dmarc-requ...@listserv.ua.edu> Sent: Friday, May 25, 2018 2:23 PM To: IBM-MAIN@listserv.ua.edu Subject: Re: How to get BPX loadhfs (BPX1LOD) to load module into writable memory? On Tue, 22 May 2018 15:27:32 -0400, Thomas David Rivers wrote: >The BPX loadhfs function (BPX1LOD) loads an HFS executable >into memory. > >It seems, that sometimes, this is loaded into writable memory >and sometimes into read-only memory. > >There doesn't seem to be a way to indicate which is desired.. is there >some OS-interface that writable memory be used? > What was Peter H. (informally?) quoting without citation? In: z/OS IBM MVS Program Management: User's Guide and Reference Version 2 Release 3 SA23-1393-30 Chapter 6. Binder options reference Binder options REUS: Reusability options` RENT The module is reenterable. It can be executed by more than one task at a time. A task can begin executing it before a previous task has completed execution. A reenterable module is ordinarily expected not to modify its own code. In some cases, MVS protects the reentrant module's virtual storage so that it cannot be modified except by a program running in key 0. These cases include programs which the system treats as having been loaded from an authorized library, and also programs running under UNIX unless a debugging environment has been specified. Reenterable modules are also serially reusable. So, WAD. I dislike some things about this: o "include" is undesirably vague. The Ref. should specify exactly the cases in which ... programs are [so] treated. A precise "are" is preferable to the imprecise "include". What other cases may there be? "[T]reats as having been ..." is likewise vague. Provide at least a citation of an explanation of what this means. o Simpler Is Better. I see no good reason to treat "programs running under UNIX" differently from other programs. o "ordinarily expected". Is this a retreat from the earlier well-known rule (cited by Peter) that a RENT program was allowed to modify its own code given proper serialization? -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
