Updating .so files for functions?

I ran into a crash that was caused by the .so files used by postgres being
overwritten ( see
http://www.postgresql.org/message-id/CAAcYxUeduPhKXbDQ6ZTOhKGE+1A3cMrTQujSExC-tv4ac4ksUw@mail.gmail.com
), so that made me wonder what the rules are for updating .so files. I read
through the documentation on C functions (
http://www.postgresql.org/docs/8.4/static/xfunc-c.html ) but didn't come to
any firm answers.

Here's our current procedure:
1) Build new .so files
2) Put new .so files in "version directory" (for example
/path/to/funcs/1.23.1/ where old version was /path/to/funcs/1.23.0/)
3) Run "ALTER DATABASE <db_name> SET dynamic_library_path TO
'/path/to/funcs/1.23.1:$libdir';"

Is that an ok operation to perform on a live database? Will existing
connections handle that without issues? (I'm ok if they still keep using
the old .so files until the connection is closed and re-opened)

Thanks,
Dave