Mapscript crashing Tomcat --> [Panic]

[Umberto Nicoletti]

On 3/28/07, Frank Warmerdam <warmerdam at pobox.com> wrote:
> Rodrigo Del C. Andrade wrote:
> >      Greetings. dear list.
> >      We are experiencing some troubling difficulties developing an
> > application with mapscript on a Java web based environment with tomcat.
> >    Here is the deal: while using the app (not nearly done, but
> > functional enough at this stage) when one tries to zoom (in or out) or
> > pan the map more than a few times, Tomcat often will go down screaming
> > and the JVM just gives up on life.
> >    I know this is probably not the right or best place to ask about it,
> > but it seems to be caused by the interaction of mapscript and the GD
> > library.
> >         Here is the JVM output short version (long version is attached
> > at the bottom):
> ...
> >    Any ideas? Full JVM error log is at the bottom. I am ready to give in
> > more info if needed.
> >    Thanks in advance;
> ...
>
> > Stack: [0xb0203000,0xb0284000),  sp=0xb0279ed4,  free space=475k
> > Native frames: (J=compiled Java code, j=interpreted, Vv=VM code,
> > C=native code)
> > C  [libgd.so.2+0x8182]
> > C  [libgd.so.2+0x9a16]  gdImageLine+0x4a6
> > C  [libmapscript.so+0xad355]
> > C  [libmapscript.so+0xb310e]  msDrawLineSymbolGD+0xe7e
> > C  [libmapscript.so+0xa75fb]  msDrawLineSymbol+0x8b
> > C  [libmapscript.so+0xa9cb2]  msDrawShape+0x17e2
> > C  [libmapscript.so+0xaa6d8]  msDrawVectorLayer+0x398
> > C  [libmapscript.so+0xaa97a]  msDrawLayer+0xaa
> > C  [libmapscript.so+0xaba67]  msDrawMap+0x6a7
> > C  [libmapscript.so+0x552b5]
>
> Rodrigo,
>
> I'd suggesting seeing if you can reproduce this without Java involved.  I
> suspect there is some sort of memory error in msDrawLineSymbolGD() (possibly
> the infamous antialiasing bug?).

Frank,
I bet it is exactly that!
Rodrigo: upgrade to gd 2.0.34 (http://www.libgd.org/Main_Page) and
tell us if the problem goes away.

Umberto

>
> Capture your map configuration into a map file, and run the map through
> shp2img or mapserv with the appropriate layers turned on, and similar
> view configuration *and* run it under "valgrind" to quickly highly
> memory corruption as soon as it happens.
>
> If you can reproduce it this way,then you have something you can file
> as a bug report.
>
> MapServer is not bug free, and it is important to be able to narrow
> down bugs without too much extraneous stuff.
>
> Best regards,
> --
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | President OSGeo, http://osgeo.org
>