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+Threads in anaconda?  No!
+David Cantrell <dcantrell@redhat.com>
+
+
+INTRODUCTION
+
+   Threads make a lot of people run screaming.  That's entirely
+   understandable because thread concurrency can be a pain.  In this short
+   document, I want to explain why threads are in anaconda and how to work
+   with them in the code.
+
+MISCONCEPTIONS
+
+   Just to make sure everyone is on the same page, threads are similar to
+   processes.  The big advantage we get is easier shared data structures.
+   Threads can communicate over more methods than just signals.  But,
+   multithreaded does not mean that we are taking every operation out to
+   a separate thread.
+
+ANACONDA THREADS
+
+   The idea for anaconda threads is to simplify life for things that can
+   or need to run parallel to other operations.  So we will reserve the
+   use of threads for tasks that fit in to this category well (the logging
+   system, for instance) and keep the bulk of the installer in the main
+   thread.
+
+THREADS AND PYTHON
+
+   Python has a nice model for threading.  Threads in Python extend the
+   threading.Thread class.  So an easy way to identify something that will
+   run or can be run as a thread is seeing a class definition like this:
+
+      class SomeClass(threading.Thread):
+
+   You still have your __init__ method for the constructor, but threads
+   also have a run() method and a join() method (there are others, but
+   I will just discuss these).
+
+   The run() method is called when you start the thread.  This is where
+   you want to do the work.  Normally this happens in the class
+   constructor, but in threads we need that separated out to a different
+   method.
+
+   The join() method is to block execution of other threads.  Whatever you
+   put in the join() method will run and other threads will be blocked
+   while it runs.  Now, this method is only run when you call it explicitly
+   from another thread, so think of it as similar to waitpid().
+
+   Python has the thread and threading modules.  Use threading as it's
+   built on top of thread and provides a threading system similar to the
+   POSIX thread model.
+
+   More information:
+      http://docs.python.org/lib/module-threading.html
+
+THREAD NAMES
+
+   Threads have names in Python.  They are automatically assigned or you
+   can specify the name.  For anaconda it probably makes more sense to
+   name our threads since we won't be launching more than one for the
+   same task.
+
+   The convention I'm using is:  NameThr
+   For example:  RelNotesThr
+
+   The name is arbitrary, but we should probably have some sort of
+   consistency.
+
+PYGTK AND THREADS
+
+   GTK+ presents the biggest challenge for threads, but it's not
+   impossible.  We will be allowing GTK+ calls from any thread, so we
+   have to call threads_init() in gui.py as the first thing:
+
+      gtk.gdk.threads_init()
+
+   After this, you can use Python threads as you normally would.  When
+   you call gtk.main(), you need to call it like this:
+
+      gtk.threads_enter()
+      gtk.main()
+      gtk.threads_leave()
+
+   Calls to PyGTK methods or fiddling with GTK objects...all that has to
+   be wrapped in threads_enter/threads_leave calls.  The suggested syntax
+   is:
+
+      gtk.threads_enter()
+      try:
+         # do stuff
+      finally:
+         gtk.threads_leave()
+
+   Suggested reading:
+
+      http://www.async.com.br/faq/pygtk/index.py?req=show&file=faq20.006.htp
+      http://developer.gnome.org/doc/API/2.0/gdk/gdk-Threads.html
+
+
+I will try to expand this document as I move through more threading code.
+Email me if you have any questions.
+
+-- 
+David Cantrell
+<dcantrell@redhat.com>