[postgis-devel] use of palloc() crashes server

[Christoph Spoerri]

I have updated my code from the CVS (postgis), but encounter still the same 
problem. Is this a document problem or has it to do with my code? Is there a 
work around about the problem?

Thanks,
Christoph

On Thursday 13 May 2004 02:32, strk wrote:
> On Wed, May 12, 2004 at 11:17:42PM -0400, Christoph Spoerri wrote:
> > Hi there,
> >
> > I'm working on a couple new function for PostGIS (dyn.
> > segmentation/linear referencing system). I ran now into the problem where
> > postgresql crashes when I'm calling line_make(). I traced it down to the
> > palloc() call within the line_make() function, but I have no idea what
> > could cause the error.
> >
> > The line I'm creating has around 370 points, and the lines where the code
> > crashes is:
> > 	result= (LINE3D *) palloc (*size); (in file: postgis_inout.c)
> >
> > And just to make the problem more confusing:
> >
> > I run the following query (after logging in):
> > select lrs_getshape(wkb_geometry, 1, 80) from test;
> > => code crashes
> >
> > yet, if I run the following sequence:
> > select lrs_getshape(wkb_geometry, 1, 20) from test;
> > select lrs_getshape(wkb_geometry, 1, 80) from test;
> > => code doesn't crash (????)
> >
> > It crashes again if I run the following sequence:
> > select lrs_getshape(wkb_geometry, 1, 20) from test;
> > select lrs_getshape(wkb_geometry, 1, 80) from test;
> > select lrs_getshape(wkb_geometry, 1, 90) from test;
> >
> > Note: lrs_getshape() accumulates the necessary points to create a new 3D
> > line.
> >
> > Any idea what could cause this? And thanks for your help,
>
> What you describe is a tipical behaviour of pointers mess.
> There's probably *always* an out-of-bounday condition, but
> sometimes the faulty memory accessed is still allocated for
> the process, sometimes not.
>
> Try CVS postgis if possible.
>
> --strk;
>
> > Christoph
> > _______________________________________________
> > postgis-devel mailing list
> > postgis-devel at postgis.refractions.net
> > http://postgis.refractions.net/mailman/listinfo/postgis-devel
>
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