RENT implies REUS..
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of Joseph Reichman [reichman...@gmail.com] Sent: Friday, February 5, 2021 3:02 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: LINK vs LOAD/CALL Sorry to jump in here but can you have rent without reus > On Feb 5, 2021, at 2:59 PM, Seymour J Metz <sme...@gmu.edu> wrote: > > If the module is not REUS then every LOAD will get a different copy. If the > module is REUS but not RENT then LOAD, ENQ, CALL, DEQ, DELETE is safe. Using > LOAD, SYNCH, DELETE is left as an excise for the reader. In most cases I > would use LINK(X). > > > -- > Shmuel (Seymour J.) Metz > http://mason.gmu.edu/~smetz3 > > ________________________________________ > From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of > Bernd Oppolzer [bernd.oppol...@t-online.de] > Sent: Friday, February 5, 2021 1:41 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: LINK vs LOAD/CALL > > I would like to add: > > while LINK is functionally the same as LOAD - CALL - DELETE, > there is an important difference: > > the transfer of control with LINK is known to the operating system, > but with LOAD - CALL - DELETE, it is NOT known. > In fact, CALL is not a supervisor action, it is simple machine > instructions (very cheap). > This means that if a module is not RENT and not REUS (for example), > a call using LOAD - CALL - DELETE is not safe, because the system does > not know that > the module is in use. Another subtask can easily call the same module at > the same time, > if it knows the address, and it will never get another copy. You are > responsible yourself > for doing things right. > > With LINK, on the contrary, if the module is not RENT and not REUS, the > system > will ALWAYS fetch a new copy, when you do another LINK. > > (There is a "use count" in the control blocks, which is incremented and > decremented > during LINK processing, but of course not, when doing a CALL). > > Kind regards > > Bernd > > >> Am 05.02.2021 um 18:54 schrieb Frank Swarbrick: >> I am not a systems programmer. I am a COBOL programmer who knows only >> enough assembler to be dangerous. >> What is the "difference" between doing a LOAD and a CALL to perform a >> dynamic call and doing a LINK? >> >> ---------------------------------------------------------------------- >> 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 > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
