g++ and multithreading?

[Sune]

Hi!

I'm confused what has to be done in the different steps of compilation
to ensure the result is truly running multithreaded... I use g++ for
C++...

1)
What do I have to do to make sure .so libs I build on Solaris 9
supports multithreaded access?

2)
What will happen if I try to access an .so lib that has not been
prepared as suggested above?

3)
What do I have to do to make sure my executable that links the .so lib
in step 1 and other .so libs compile for multithreaded execution?

Thanks a lot in advance
/Sune