Shared libraries: How to share global variaables?

Is it possible to share global variables such that all applications
which use shared libraries can see the changes made to the global
variables by the other applications.

I use gcc and compiled
      gcc -shared -Wl,-soname,xyz.so.1 -o libxyz.so.1.0 -lxyz2  abc.o

Regards,
Nagaraju.