Reentrant means that it works correctly when multiple tasks are using it concurrently. Refreshable means that it works correctly even if the OS replaces it with a clean copy.
As an example of a routine that is reentrant but not refreshable, consider a routine that contains a data area and serializes access with CS or CDS. It will work correctly when invoked in parallel from multiple tasks, but refreshing the module would clear the count. As an example of a routine that is refreshable but not reentrant, consider a routine that updates CVTUSER without serializing it in any way. However, 99% of the time a routine intended to be reentrant will not only be refreshable but will run correctly from read-only storage, while routines intended to be refreshable will also be reentrant. I believe that IBM has fixed all the legacy self-modifying reentrant code from OS/360. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of Rob Schramm [rob.schr...@gmail.com] Sent: Wednesday, February 15, 2023 5:34 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Are JNI required to be re-entrant and/or re-usable? Ok.. so I am not sure I ever asked this question... What is the real difference between reentrant and refreshable .. as in an example? It is not clear what the distinction actually is. Rob On Wed, Feb 15, 2023, 16:34 Attila Fogarasi <fogar...@gmail.com> wrote: > IBM documents this crisply at > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ibm.com%2Fdocs%2Fen%2Fzos%2F2.1.0%3Ftopic%3Dmodules-module-reusability&data=05%7C01%7Csmetz3%40gmu.edu%7C5e072c5fa10b4bad441b08db0fa4efef%7C9e857255df574c47a0c00546460380cb%7C0%7C0%7C638120973304572606%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=FbfDzXWjN%2BhRrq7gYp5Zjfyb3A00LrinApK3u%2BKHU4U%3D&reserved=0 > Bottom line is that there are only 3 variants: serially reusable, > reentrant and refreshable. > Non-serially reusable is reentrant, but that term isn't used in Binder or > z/OS doc (thankfully). > > On Thu, Feb 16, 2023 at 8:07 AM Phil Smith III <li...@akphs.com> wrote: > > > I feel stoopid[er than usual]: I don't understand the difference between > > "serially reusable" vs. "reusable" vs. "reentrant" in this context. I > know > > what the first and last one are, but it seems like the middle one should > be > > the same as one of the others. > > > > > > > > Unless the difference between the latter two is that "reusable" means > "one > > user running a shared copy at a time without reloading" and "reentrant" > > means "multiple users running the same copy at the same time"? Peter? > > > > > > ---------------------------------------------------------------------- > > 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
