+=head2 MULTIPLE HANDLES AND MULTIPLE THREADS
+
+The support for multiple handles and multiple threads is modelled
+after glib (although doesn't require glib, if you use the select-based
+main loop).
+
+L<http://library.gnome.org/devel/glib/unstable/glib-The-Main-Event-Loop.html>
+
+You will need to create one main loop for each thread that wants to
+use libguestfs. Each guestfs handle should be confined to one thread.
+If you try to pass guestfs handles between threads, you will get
+undefined results.
+
+If you only want to use guestfs handles from one thread in your
+program, but your program has other threads doing other things, then
+you don't need to do anything special.