Global Symbol Evaluation

Are you working on Linux?

Have you ever seen a file with this *.sog extension in your plug-in directory?

Ever wonder what it is?

It is possible to force plug-ins to export their symbols by putting an additional file, with the same name as the plug-in with the extension '.sog' in the directory with the plug-in. This would cause the plug-in to be dlopened using the RTLD_GLOBAL flag.

The .sog extension is our own indication that a plug-in should be loaded with extra loader options.  The RTLD_GLOBAL flag.   Normally we don't set this flag so any functions will be known to the plug-in itself and not pollute the global name space.

Normal plug-in loading:

• pluginName.so

To load a plug-in with RTLD_GLOBAL flag included:

• pluginName.so
• pluginName.sog

The ending ‘g’ meaning global.

You need both files.  The .sog is there for existence only - can be a zero length file.

They should ensure the other plug-in that exports its functions has a .sog file to match that plug-in so it is loaded with global scope.

The presence of a .sog file will enable the plug-in symbols to be available for other plug-ins to use.

Cheers,

Kristine