Re: [Xsb-development] XSB and Java

[<ki...@cs...>]

Hi, Stefan,
couldn't try your test as given because you didn't supply HelloWorld.h,
but I eliminated the java stuff and ran  several times the program below.
In none of the cases (redhat6.1) did I get a coredump.

I might still be an xsb bug, because it is known to have hard-to-reproduce
memory bugs. But is could also be something else. Try the program below and
see if it crashes on your system.


	--michael  


//#include <jni.h>
//#include "HelloWorld.h"
#include <stdio.h>
/* The cinterf.h for XSB   */
#include <cinterf.h>
//JNIEXPORT void JNICALL
//Java_HelloWorld_displayHelloWorld(JNIEnv *env, jobject obj){
main(argc,argv){
   int rcode;
   int myargc = 2;
   char *myargv[2];
   myargv[0] = "/home/users/kifer/XSB/XSB/";
   myargv[1] = "-n";
   xsb_init(myargc,myargv);
   printf("Hello world!\n");
   return;
}


> Hi XSBers,
> 
> I try to built a Java Native Interface for XSB: I want to be able to
> access XSB from Java directly (without using TCP/IP as e.g. Interprolog does).
> I'am working with Linux Redhat 6.2 and using Suns JDK1.3.
> I've written (or copied together) the following C-Code (HelloWorld.c):
> This is just an example that initializes XSB (and prints out "Hello World").
> 
> #include <jni.h>
> #include "HelloWorld.h"
> #include <stdio.h
> /* The cinterf.h for XSB   */
> #include <cinterf.h>
> JNIEXPORT void JNICALL
> Java_HelloWorld_displayHelloWorld(JNIEnv *env, jobject obj){
>    int rcode;
>    int myargc = 2;
>    char *myargv[2];
>    myargv[0] = "/local/xsb/XSB";
>    myargv[1] = "-n";
>    xsb_init(myargc,myargv);
>    printf("Hello world!\n");
>    return;
> }
> ****************************************************************************
> 
> I produced a shared libarary libhello.so, that consists of XSB.o, HelloWorld.o
> and the required libraries.
> The following Java-Program loads libhello.so and calls the native method:
> 
> class HelloWorld {
>      public native void displayHelloWorld();
>      static {       System.loadLibrary("hello"); }
>      public static void main(String[] args) {
>          new HelloWorld().displayHelloWorld();
>      }
> }
> 
> If I now do a "java HelloWorld", sometimes the world is nice and I get:
> 
>  > java HelloWorld
> [xsb_configuration loaded]
> [sysinitrc loaded]
> [packaging loaded]
> Hello world!
> 
> which is exactly what I would expect.
> But usually the world is not nice  and I get:
> 
> ++Memory violation occurred during evaluation.
> ++Please report this bug using the XSB bug tracking system:
> ++       http://sourceforge.net/bugs/?group_id=1176
> ++and to xsb...@li....
> ++Please supply the steps necessary to reproduce the bug.
> ! Aborting...
> 
> ++Memory violation occurred during evaluation.
> ++Please report this bug using the XSB bug tracking system:
> ++       http://sourceforge.net/bugs/?group_id=1176
> ++and to xsb...@li....
> ++Please supply the steps necessary to reproduce the bug.
> ! Aborting...
> etc.
> There was no difference between the two calls - sometimes the
> call succeeds, sometimes (more often) not.
> Any idea what this could be? (Alignment?)
> (If it helps I can of course also send the Makefile etc.)
> 
> Thanks a lot and all the best,
> 
> 	Stefan Decker
> 
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