Re: scheduler going backwards in time

[Lloyd Wood <L.Wood@surrey.ac.uk>]

On 31 Aug 1999, Yuri Pryadkin wrote:

> Search the list archive for this particular error message.
> 
> Basically, you have two alternatives:
> 
> 1.  Update your scheduler.cc file from the daily snapshot/CVS tree.
> 2.  Use Heap scheduler instead of the default Calendar.


Hmm. I upgraded from snapshot of 30 Jun to 30 Aug snapshot yesterday.
On running fire-a-CBR-packet-off-once-a-minute-over-Teledesic scripts
exercising Tom's satellite code, I get 'scheduler going backwards in
time' warnings (below)  just before the cutoff-for-a-day of 86400
seconds, although the tracefile completes.
 
Turns out all my previous tracefiles from the old ns build stopped at
86341.something just as the first back-in-time warning would have been
noted (hence I was always graphing a day of 23.98 hrs) so this
actually seems like a visible improvement. Until you notice that the
calendar scheduler is going backwards in time TWENTY-TWO SECONDS - far
longer than the lifetime of any traffic in the network.

Is that excessive, or is it just me?

thanks,

L.

>   -Yuri
> 
> Tan Yuan Sin <eng70202@nus.edu.sg> writes:
> 
> > I was running a simulation using the DSR protocol when I encounter these
> > error messages :
> > .
> > .
> > .
> > .
> > ns: scheduler going backwards in time from 242.584536 to 242.551853.
> > ns: scheduler going backwards in time from 242.585224 to 242.552483.
> > ns: scheduler going backwards in time from 242.585562 to 242.552831.
> > ns: scheduler going backwards in time from 242.585736 to 242.552969.
> > ns: scheduler going backwards in time from 242.586139 to 242.553404.
> > Assertion failed: rtime >= 0.0, file mac-timers.cpp, line 265
> > 
> > abnormal program termination
> > 
> > Can anyone help me on this. Thank you very much.

<L.Wood@surrey.ac.uk>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>

ns: scheduler going backwards in time from 86363.259708 to
86341.001205.
ns: scheduler going backwards in time from 86364.870297 to
86344.019131.
ns: scheduler going backwards in time from 86371.616965 to
86349.511922.
ns: scheduler going backwards in time from 86372.370309 to
86350.821219.
ns: scheduler going backwards in time from 86375.096118 to
86352.931369.
ns: scheduler going backwards in time from 86375.509782 to
86353.284242.
ns: scheduler going backwards in time from 86375.900676 to
86353.865821.
ns: scheduler going backwards in time from 86376.968750 to
86354.981619.
ns: scheduler going backwards in time from 86378.064471 to
86356.099807.
ns: scheduler going backwards in time from 86378.441588 to
86356.374729.
ns: scheduler going backwards in time from 86379.039294 to
86357.155454.
ns: scheduler going backwards in time from 86380.144106 to
86358.479358.
ns: scheduler going backwards in time from 86380.971975 to
86358.774408.
ns: scheduler going backwards in time from 86381.190341 to
86359.229663.
ns: scheduler going backwards in time from 86381.757953 to
86359.543498.
ns: scheduler going backwards in time from 86381.860842 to
86359.854493.
ns: scheduler going backwards in time from 86382.172629 to
86360.192204.
ns: scheduler going backwards in time from 86383.086557 to
86360.920291.
ns: scheduler going backwards in time from 86383.360882 to
86361.241729.
ns: scheduler going backwards in time from 86383.710048 to
86361.813936.
ns: scheduler going backwards in time from 86386.285256 to
86364.252579.
ns: scheduler going backwards in time from 86386.562349 to
86364.353521.
ns: scheduler going backwards in time from 86386.805961 to
86364.694326.
ns: scheduler going backwards in time from 86387.413335 to
86365.499609.
ns: scheduler going backwards in time from 86388.160210 to
86366.592334.
ns: scheduler going backwards in time from 86388.826841 to
86366.805139.
ns: scheduler going backwards in time from 86389.463936 to
86367.404460.
ns: scheduler going backwards in time from 86390.111375 to
86367.829990.
ns: scheduler going backwards in time from 86390.467072 to
86368.368814.
ns: scheduler going backwards in time from 86390.899306 to
86368.884665.
ns: scheduler going backwards in time from 86391.585687 to
86369.371646.
ns: scheduler going backwards in time from 86391.698223 to
86370.091762.
ns: scheduler going backwards in time from 86392.556986 to
86370.300194.
ns: scheduler going backwards in time from 86392.683724 to
86370.866712.
ns: scheduler going backwards in time from 86394.019625 to
86371.744837.
ns: scheduler going backwards in time from 86396.354497 to
86374.397704.
ns: scheduler going backwards in time from 86396.639359 to
86374.611425.
ns: scheduler going backwards in time from 86397.731455 to
86375.684266.
ns: scheduler going backwards in time from 86398.455656 to
86376.728198.
ns: scheduler going backwards in time from 86399.407977 to
86377.482173.
ns: scheduler going backwards in time from 86399.724441 to
86377.735283.
ns: scheduler going backwards in time from 86400.662978 to
86378.390093.
ns: scheduler going backwards in time from 86401.032523 to
86378.683446.
ns: scheduler going backwards in time from 86401.033729 to
86379.153603.
ns: scheduler going backwards in time from 86401.473177 to
86379.414821.
ns: scheduler going backwards in time from 86402.501532 to
86380.461891.
ns: scheduler going backwards in time from 86402.981035 to
86381.055428.
ns: scheduler going backwards in time from 86403.273191 to
86381.126329.
ns: scheduler going backwards in time from 86404.094230 to
86381.847215.
ns: scheduler going backwards in time from 86404.880824 to
86383.342652.
ns: scheduler going backwards in time from 86406.022710 to
86383.972632.
ns: scheduler going backwards in time from 86408.514546 to
86386.367809.
ns: scheduler going backwards in time from 86408.981248 to
86386.888551.
ns: scheduler going backwards in time from 86409.364170 to
86387.185262.
ns: scheduler going backwards in time from 86409.524555 to
86387.414636.
ns: scheduler going backwards in time from 86409.906297 to
86387.870798.
ns: scheduler going backwards in time from 86410.190880 to
86388.262225.