[GiNaC-list] How (not) thread-safe is ginac?

I am planning to use ginac for mathematic implementations which can (and should) be parallelized. However, I found hints that ginac is not thread-safe. The only thing in the source code was here: http://www.ginac.de/ginac.git?p=ginac.git;a=blob;f=ginac/ptr.h If I understand this right, the reference counting should be protected by mutexes and one would have to think of a way to avoid certain race conditions with makewritable(). What else is there in ginac that would need to be changed for thread-safety? Note that I do not plan to share any objects but only the symbols I use between threads, so I probably could (temporarily) work with a version that is only partially thread-safe. Thanks for your replies Thomas