On Sun, 18 Feb 2024 18:22:53 -0600, Peter Farley wrote: > >The only HLL-callable function already provided in z/OS that I can find that >provides anything near that resolution is the LE Callable Services function >CEEGMT, but two calls to that service from a COBOL program in a row separated >by only a few calculations and a DISPLAY to SYSOUT produce identical values. >This is not good enough for high-volume processing needs. Every request for a >time value needs to generate a new higher value. > What guarantees uniqueness other than STCT(E)? Does the Sysplex Timer/ETR guarantee uniqueness across the plex?
And monotonicity is a harsher constraint. In the Bad Old Days when each CPU had its own TOD and uniqueness was achieved by putting the CPU ID in the TOD programmable field I wondered hereabouts whether a later transaction on a lower CPU could get lower timestamp than an earlier transaction on a higher CPU. And even if a service such as STCKE returns unique values, conversion to displayable nanoseconds can result in duplicates. You need a serialized service common to all participating processes that returns unique values in a specified format. Performance may suffer. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
