[mapserver-users] Re: MapScript migration problems

[Rob]

For future reference, I had applied the rpl_malloc change to the
mapprimitive.c file, but this hadn't been picked up by
maporaclespatial.c

I've removed the mapprimitive.c reference and put it into mapserver.h
between the _WIN32 and DISABLE_CVSID #ifdef statements.

2008/6/6 Rob <gis at vanbooth.com>:
> Hi
>
> I'm trying to migrate my MapServer 4.8.6 mapscript application to 5.0.2.
>
> I've seen the following webpages, and this has identified a number of
> things that I need to do, which I have started on
>
> http://mapserver.gis.umn.edu/download/previous/mapserver_4_10/migration_guide_48_410
> http://trac.osgeo.org/mapserver/browser/tags/rel-5-0-0/mapserver/MIGRATION_GUIDE.TXT
>
>
> I've had some success so far, with shapefiles, rasters and cascaded
> WMS feeds, but I've just hit a problem when trying to view an Oracle
> layer.
>
> I am seeing the following error.
>
> "msOracleSpatialLayerNextShape(): OracleSpatial error :  No memory
> avaliable to allocate the values" [TYPO in the error message BTW]
>
> This seems to be for any Oracle layer, including a test layer with
> only 12 points in it, so I can't believe it really is an available
> memory issue.
>
> Looking at the MapServer code directly, this error message comes from here
>
>        shape->values = (char **)malloc( sizeof(char*) * shape->numvalues );
>        if (shape->values == NULL)
>        {
>            msSetError( MS_ORACLESPATIALERR, "No memory avaliable to
> allocate the values", "msOracleSpatialLayerNextShape()" );
>            return MS_FAILURE;
>        }
>
> For some background, my application is running on AIX, and I from what
> I can gather thats an issue with regards to MALLOC.  From our internal
> documentation of how we resolved the issue on 4.8.6
>
> "Malloc on AIX differs from other platforms, in particular attempting
> to allocate zero bytes e.g. malloc(0) does not work on AIX. This
> causes problems with mapserver, where malloc(0) is used, often to
> create an empty structure then add 'points' etc to this structure.
> This problem allows the mapserver to be built but executing the server
> causes SIGSEGV-11 memory errors when the code attempts to reference
> the memory it expects to have been allocated by malloc(0).
>
> To fix this malloc is replaced with some rpl_malloc.c macro so as to
> handle malloc(0)
>
> Add rpl_malloc.o to the object list in the Makefile
>
> OBJS= maptemplate.o …… rpl_malloc.o $(EPPL_OBJ)
>
> And define the macro to override malloc with rpl_malloc in the file
> mapprimitive.c
>
> /* Deal with AIX malloc(0) issues */
>
> #define malloc rpl_malloc
>
> "
>
> We've done this again this time round, and resolved the SIGSEGV issues
> that still existed.
> I have no idea whether this is part of the issue, but I thought it
> might be relevant given the location of the error in the code.  If
> not, then doesn anybody of any of the parameters needed for an
> OracleSpatial layer have changed between the versions?
>
> MTIA
>
> Rob
>