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Re: scheduler going backwards solution?
On 7 Sep 1999, Yuri Pryadkin wrote:
> Xin Wang <[email protected]> writes:
>
> > There were a lot of discussions on "scheduler going backwards" problem
> > in this list. I wonder what is the final solution?
>
> I think I can summarize it as follows:
>
> 1. If you see this warning, the first thing you should do is to make
> sure you're using the latest version of scheduler.cc. If necessary,
> get the latest version from
> http://www-mash.cs.berkeley.edu/cgi-bin/cvsweb/ns-2/scheduler.cc
> Don't forget to recompile. If after that you still see this error
> message, please report this to the list.
>
> 2. If the previous didn't work for you, use Heap scheduler instead of
> default Calendar (see Simulator instproc use-scheduler command and
> nsdoc). Heap scheduler, although a little less effective than
> Calendar, doesn't have a numeric stability problem and should not
> give you this error. Again, if it does, please report this to the
> list.
[..]
> There is only one central scheduler in ns which manages a single queue
> of timed events. It's Calendar by default, but you can switch to
> using Heap or List.
Question: why isn't Heap the default? Faster than list, even more
solid than Calendar. Calendar's added desk calendar wrapping feature
doesn't strike me as that useful for 99.999% of ns use (ditto for
List's preserving ordering of simultaneous events.)
L.
<[email protected]>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>