On Friday 22 June 2018 08:47:05 andy pugh wrote: > I haven't seen this mentioned here. It seems that it might be > relevant: > > https://www.raspberrypi.org/forums/viewtopic.php?t=206747
I almost missed this, bookmarked now, thanks Andy. This thread got into a serious list of questions about how it was done, so let me describe how Jim and I wrote a cron for amigados, which at the time we started, was littered with several such utilities, all of which busy waited between jobs, and were a huge waste of cpu resources. At that time we were using Bill Hawes ARexx as a substitute for a shell like bash because Bill had incorporated the system calls in ARexx we needed to do it what we considered the right way. We concocted a way to get the time that gave it to us in ticks, and when it had finished with this minutes jobs, we calculated how many ticks we'd need to sleep in order to stop wasting cpu, and put it to sleep to be woke up again in the first tick of a new minute. Compiled with rexxplus, the overall cpu loading was well under .01%, and when published, took over the cron jobs all over the planet in an estimated month. So that timed sleep was at the time, a concept that changed how tv graphics was done in very short order. That ARexx was one hell of a concept, and no other os has ever chosen to allow its innards to be so exposed. The worst part of that was that Bill never got a dime from commie for writing it. I wish we had it for linux, we could write linuxcnc in it. Sadly all we have is Regina, a totally useless subset of the original Rexx. -- Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
