Dealing with LD_LIBRARY_PATH for a package using JNI

[Mary Ellen Foster]

I'm currently working on enabling the "jpl" Java interface to the SWI
Prolog (package is called "pl" in Fedora). This provides a
bidirectional interface between Prolog and Java -- you can call Prolog
from Java or (what I'm doing in my current project) call Java from
Prolog.

I'm attempting to follow the Java packaging guidelines for JNI-using
projects and putting jpl.jar and libjpl.so into $LIBDIR/pl-jpl and
patching files so that the libraries get loaded, and that's going
well.

One thing I'm not sure how to deal with: libjpl.so is linked against
libjava.so and libjvm.so. On my machine, that means I need to set
LD_LIBRARY_PATH to
/usr/lib/jvm/java/jre/lib/i386:/usr/lib/jvm/java/jre/lib/i386/client
before I run Prolog, and the same is probably the case if I wanted to
use the Java-to-Prolog direction. Is this acceptable, or is there some
other solution I should use here?

Thanks for any suggestions,

MEF

-- 
Mary Ellen Foster  --  http://homepages.inf.ed.ac.uk/mef/
Informatik 6: Robotics and Embedded Systems, Technische Universität München
and ICCS, School of Informatics, University of Edinburgh

[Andrew Haley]

Mary Ellen Foster wrote:
>  I'm currently working on enabling the "jpl" Java
> interface to the SWI
>  Prolog (package is called "pl" in Fedora). This provides a
>  bidirectional interface between Prolog and Java -- you can call Prolog
>  from Java or (what I'm doing in my current project) call Java from
>  Prolog.
>  
>  I'm attempting to follow the Java packaging guidelines for JNI-using
>  projects and putting jpl.jar and libjpl.so into $LIBDIR/pl-jpl and
>  patching files so that the libraries get loaded, and that's going
>  well.
>  
>  One thing I'm not sure how to deal with: libjpl.so is linked against
>  libjava.so and libjvm.so. On my machine, that means I need to set
>  LD_LIBRARY_PATH to
>  /usr/lib/jvm/java/jre/lib/i386:/usr/lib/jvm/java/jre/lib/i386/client
>  before I run Prolog, and the same is probably the case if I wanted to
>  use the Java-to-Prolog direction. 
The command-line program 'java' already sets its LD_LIBRARY_PATH, so
it shouldn't be necessary when calling from Java.

Andrew.

[Mary Ellen Foster]

On 08/04/2008, Andrew Haley <aph(a)redhat.com&gt; wrote:
>  Mary Ellen Foster wrote:
>   > One thing I'm not sure how to deal with: libjpl.so is linked against
>   > libjava.so and libjvm.so. On my machine, that means I need to set
>   > LD_LIBRARY_PATH to
>   > /usr/lib/jvm/java/jre/lib/i386:/usr/lib/jvm/java/jre/lib/i386/client
>   > before I run Prolog, and the same is probably the case if I wanted to
>   > use the Java-to-Prolog direction.
>
>  The command-line program 'java' already sets its LD_LIBRARY_PATH, so
>   it shouldn't be necessary when calling from Java. 
Okay, so this is just a problem if I want to run Prolog and access
Java from inside there. Is it acceptable to tell people to set their
LD_LIBRARY_PATH if they want to use jpl in this direction? That's
essentially what upstream tells you to do (except they describe the
Windows case): http://www.swi-prolog.org/packages/jpl/installation.html

MEF

-- 
Mary Ellen Foster  --  http://homepages.inf.ed.ac.uk/mef/
Informatik 6: Robotics and Embedded Systems, Technische Universität München
and ICCS, School of Informatics, University of Edinburgh