[mapserver] Java VM Crashes using the Mapscript API

[Sean Gillies]

I'm forwarding this to the users list. Hopefully, Umberto will be able 
to provide some insight.

cheers,
Sean

On Jun 16, 2005, at 5:08 PM, Christian Schröder wrote:

> Dear Mr. Gillies,
>
> some weeks ago me and Florian Pepping contacted you because we had 
> problems using the Java Mapscript API. Thanks to you we could solve 
> these problems :-)
>
> Now we got our program doing what it's supposed to do but there is 
> still a big problem left which we were not able to solve yet:
> We created a simple servlet which is created inside a Tomcat 5.0 
> Webserver. This servlet created a map image (png/jpg) and displays 
> some specified objects on the map. (We use it for location based 
> services --> "show me the position of the next printer").
> After an irregular number of calls of our servlet which uses the Java 
> Mapscript API the complete Java VM and with it the Tomcat crashes. I 
> attached the error report below. The program works properly for a 
> number of calls (between 5 and 1000 :-) ) and after that it crashes.
> We have tried several versions of the mapserver (4.4.1, 4.4.2, 4.2.4, 
> 4.6.1 RC1) and compiled the Java Mapscript Module with JDK 1.4.2 and 
> 1.5.0. We also configured mapserver using the --with-threads option, 
> but all this did not help. By the way the mapserv cgi-module works 
> properly.
>
> Do you have an idea for this?
>
> Thanks for your anxiety
>
> Christian & Florian
> University of Paderborn, Germany
>
>
> -------------------------------------------------------------------
>
> JavaMapscriptLoader: mapscript native library has been loaded.
>  * mapscript native library loaded *
>
> An unexpected exception has been detected in native code outside the 
> VM.
> Unexpected Signal : 11 occurred at PC=0x3338268
> Function=delete_classObj+0x8
> Library=/usr/lib/libmapscript.so
>
> Current Java thread:
>         at edu.umn.gis.mapscript.mapscriptJNI.delete_classObj(Native 
> Method)
>         at edu.umn.gis.mapscript.classObj.delete(classObj.java:32)
>         at edu.umn.gis.mapscript.classObj.finalize(classObj.java:26)
>         at java.lang.ref.Finalizer.invokeFinalizeMethod(Native Method)
>         at java.lang.ref.Finalizer.runFinalizer(Finalizer.java:83)
>         at java.lang.ref.Finalizer.access$100(Finalizer.java:14)
>         at 
> java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:160)
>
> Dynamic libraries:
> Can not get information for pid = 10558
>
> Heap at VM Abort:
> Heap
>  def new generation   total 1152K, used 135K [0x08ae0000, 0x08c20000,
> 0x08fc0000)
>   eden space 1024K,   0% used [0x08ae0000, 0x08ae4078, 0x08be0000)
>   from space 128K, 100% used [0x08c00000, 0x08c20000, 0x08c20000)
>   to   space 128K,   0% used [0x08be0000, 0x08be0000, 0x08c00000)
>  tenured generation   total 15048K, used 13624K [0x08fc0000, 
> 0x09e72000,
> 0x0cae0000)
>    the space 15048K,  90% used [0x08fc0000, 0x09d0e1c0, 0x09d0e200,
> 0x09e72000)
>  compacting perm gen  total 18432K, used 18373K [0x0cae0000, 
> 0x0dce0000,
> 0x10ae0000)
>    the space 18432K,  99% used [0x0cae0000, 0x0dcd1618, 0x0dcd1800,
> 0x0dce0000)
>
> Local Time = Tue Jun 14 15:32:19 2005
> Elapsed Time = 246
> #
> # The exception above was detected in native code outside the VM
> #
> # Java VM: Java HotSpot(TM) Client VM (1.4.2_08-b03 mixed mode)
> #
> # An error report file has been saved as /tmp/hs_err_pid10558.log.
> # Please refer to the file for further information.
> #
>
> -------------------------------------------------------------------
>
> On Mar 22, 2005, at 12:02 PM, Florian Pepping wrote:
>
>> Dear Mr. Gillies,
>>
>> I’m a student of the University of Paderborn in Germany and member of 
>>  the project group “Location Based Services for Wireless Devices”. In 
>>  this project we try to position laptops and other WLAN-enabled 
>> devices  using the signal strength of the WLAN. According to their 
>> position, we  want to offer location based services to the persons 
>> using the devices  (where I am; where’s the next printer; is there a 
>> friend nearby)
>>
>> In order to do this, we want to use your mapserver and the Java  
>> Mapscript API to generate maps according to the actual position and  
>> situation. We like to customize the map of our building and add  
>> points, lines and so on.
>>
>> We have been able to compile the whole mapserver and the Java  
>> Mapscript API. A small Java example also works, which presents an  
>> unchanged map of our building.
>>
> > [...]
>