> the os would first need to unload the shared library, thus if two services need the same library you need to stop both first and start them again. No, that's

> the os would first need to unload the shared library, thus if two services need the same library you need to stop both first and start them again. No, that's not how it works, at least on Unix systems. Shared libraries are mapped into each process's address space separately; there's no system-wide mechanism that prevents different processes from running different versions of the same library at the same time.