dependent system libraries - LD_LIBRARY_PATH workaround

Section 4.2 'Setting System Properties' of the

JNLP Specification states..

"The property element defines a system property that

will be available through the System.getProperty and

System.getProperties methods. Is has two required

attributes: name and value. For example:"

<property name="key1" value="value1"/>

Or in your case, something like..

<property name="LD_LIBRARY_PATH" value="/the/path"/>

I expect the application will need to have

all-permissions, to set that property.

Message was edited by:

AndrewThompson64

AndrewThompson64a at 2007-7-29 12:01:04 >

> In this case however the path is undetermined until the

> JWS engine extracts the JAR that contains the libA.so

> and the libB.so ...

Finding things in the cache is a lost cause.

This application will need to use 'variant 1 of

plan a'. This basically amounts to using a JWS

intaller-desc element* that calls Java classes that

download the shared objects and cache them on

a 'known' path. e.g.

${user.home}/com/ourcompany/ourcompanyexecutables/

Then add that path to the properties. Obviously the

property declaration in the JNLP will be redundant.

* Here is an example of using an installer.

<http://www.physci.org/jws/#eis>

Message was edited by:

AndrewThompson64

AndrewThompson64a at 2007-7-29 12:01:04 >

...

> In this case however the LD_LIBRARY_PATH

> environment variable needs to be set.

Yes. I got the point about it being an environment

variable. You missed part of my point. I will try to

explain better by asking.

Can you set the environment variable from Java code?

If it is possible to do that, the code can be called

from the Java code in the installer, after it

writes the libraries to the path.

> Or finding a workaround ...

Failing that (I do not have much experience trying

to manipulate env. vars. using anything but the OS'

own control panel), the only thing I can think of is

to get a plaform specific installer to do it for you.

Note that the native installer could also be

invoked from the web start installer code,

but I have no immediate suggestions on

native installers.

AndrewThompson64a at 2007-7-29 12:01:04 >

Andy,

this is not true, see:

public class NativeDepTest

{

public static void main ( final String[] args )

{

System.loadLibrary( "vtkCommon" );

System.loadLibrary( "vtkFiltering" );

}

}

This code will fail on the second loadLibrary() call if the LD_LIBRARY_PATH is not set.

And there is no circular dependency between the two libs, see:

$ ldd ./libvtkCommon.so

linux-gate.so.1 => (0xffffe000)

libpthread.so.0 => /lib/tls/i686/cmov/libpthread.so.0 (0xb7d56000)

libdl.so.2 => /lib/tls/i686/cmov/libdl.so.2 (0xb7d52000)

libstdc++.so.5 => /usr/lib/libstdc++.so.5 (0xb7c97000)

libm.so.6 => /lib/tls/i686/cmov/libm.so.6 (0xb7c70000)

libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb7c64000)

libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7b23000)

/lib/ld-linux.so.2 (0x80000000)

$ ldd ./libvtkFiltering.so

linux-gate.so.1 => (0xffffe000)

libvtkCommon.so => ./libvtkCommon.so (0xb7d69000)

libpthread.so.0 => /lib/tls/i686/cmov/libpthread.so.0 (0xb7d45000)

libdl.so.2 => /lib/tls/i686/cmov/libdl.so.2 (0xb7d40000)

libstdc++.so.5 => /usr/lib/libstdc++.so.5 (0xb7c86000)

libm.so.6 => /lib/tls/i686/cmov/libm.so.6 (0xb7c5f000)

libgcc_s.so.1 => /lib/libgcc_s.so.1 (0xb7c53000)

libc.so.6 => /lib/tls/i686/cmov/libc.so.6 (0xb7b12000)

/lib/ld-linux.so.2 (0x80000000)

(VTK is free, if you want to try it yourself.)

Marton

Message was edited by:

Marton.Sigmond

Marton.Sigmonda at 2007-7-29 12:01:04 >

Any idea on this?

Thanks: Marton

Marton.Sigmonda at 2007-7-29 12:01:04 >

This was the first thing I tried ... without success.

The problem is that the JWS engine extracts both the libA.so and the libB.so into the cache, and adds the cache directory to the java.library.path property, but not to the LD_LIBRARY_PATH environment variable.

SInce the operating system searches libraries in paths specified by the LD_LIBRARY_PATH, opening the libA.so will fail due to the missing dependent library: libB.so.

Marton

Marton.Sigmonda at 2007-7-29 12:01:04 >