If you are writing a program that only you execute a few times a day (under 100) you do not need to worry about reentrancy.
If it is run many times within your address space, it can be in your steplib; making it reentrant means you get the benefits of one copy, and no changes to the code If it is system wide, and run in many address spaces then you can get additional benefits of putting it into the LPA, so there is only one copy system wide rather than one (or more) per address space. Some CICS programs execute many hundred times a second with thousands of users. This would suffer if you had a non reentrant program per user. You would have the overhead of the O/S creating a copy for each user. So it depends on what you want to do. On Fri, 23 Aug 2024 at 17:30, Richard Zierdt < richard.zie...@freschesolutions.com> wrote: > Some assembly textbook authors advise always writing reentrant code > "because you never know if your program will be" [placed in some library / > system space]. > The question is: where (e.g. what libraries) must programs be reentrant to > be "allowed in" ? > Besides specific libraries (if any), are there other advantages to > reentrant code ? > Thanks -- > Richard Zierdt > > Confidentiality Warning/Avertissement de confidentialité: > > This message is intended only for the named recipients. This message may > contain information that is privileged or confidential. If you are not the > named recipient, its employee or its agent, please notify us immediately > and permanently destroy this message and any copies you may have. Ce > message est destiné uniquement aux destinataires dûment nommés. Il peut > contenir de l'information privilégiée ou confidentielle. Si vous n'êtes pas > le destinataire dûment nommé, son employé ou son mandataire, veuillez nous > aviser sans tarder et supprimer ce message ainsi que toute copie qui peut > en avoir été faite. > > ---------------------------------------------------------------------- > 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
