multirhreading&boost.python

[joop renes]

hi,
i hope this is the right list for the following question of a c++
hacker,python newbie. i have a library in c++ to which i want to add a
python GUI and other python stuff.The library has multithreading
components, while python uses a reference counted memory model. Usually
mixing reference counting with multithreading is frowned upon, at least
in the c++ world. what am i to expect in the python world, if i bring
multithreading c++ into it? just performance penalty or total disaster?
best regards
joop renes.