Comment 3 for bug 555873

Per-thread data can be managed using GPrivate variables...
http://library.gnome.org/devel/glib/unstable/glib-Threads.html#GPrivate

Making a blocking-wait inside the user-defined callback could be hard to implement, but not impossible... and quite nasty regarding the API, as it would mean publishing the internal Jardin Connection inside the recv_context_s, and also publishing all Jardin Connection methods in the public Jardin API... or making a whole set of new methods on top of Jardin Server directly to manage the underlying Jardin Connection.