Subject: Re: settimeofday() versus interval tim{ers,ing}
To: Jonathan Stone <jonathan@dsg.stanford.edu>
From: Perry E. Metzger <perry@piermont.com>
List: tech-kern
Date: 09/30/1996 21:03:29
Jonathan Stone writes:
> I'm just pointing out that as soon as one divorces the "real time" as
> measured by interval timers, and by the Correct Time of Day, that
> *some* applications* really need to wait for an interval as measured
> by Correct Time Of Day .  Dennis is punting on apps that want to sleep
> until a specific *real time*, not for an *interval*.  You're right
> that I'm objecting to that.

Almost any appliction that want so do something clock like has to
assume right now that it might wake up at the wrong time for whatever
reason. Among other things, you are supposedly sleeping for a fixed
number of seconds, not wall time, according to the specs, and you
can't be guaranteed that the system will wake you up given the
vagaries of system load and such. Given this, I do not think it is so
bad that we accept this as a possible problem.

BTW, applications that want to sleep a long time (say an hour) are
almost always better off sleeping less than that and "correcting"
periodically.

Perry