#  wise words of muppet  ##############################
That example predates some other important developments in threading  
support...

You want to have:

    use Gtk2 '-init', '-threads-init';
    
    The -threads-init import option is equalivent to calling  
    Gtk2::Gdk::Threads->init().  This makes the calls to  
    Gtk2::Gdk::Threads->enter() and Gtk2::Gdk::Threads->leave() actually  
    have effect for wrapping calls to gui functions from child threads;  
    see the C reference docs for gdk_threads_enter() and gdk_threads_leave 
    ().
    
    
    You'll also want to call Glib::Object->set_threadsafe (TRUE); before  
    doing much of anything; this enables object tracking within the  
    bindings, to avoid the "object destroyed out from under you"  
    problem.  The bindings must be built with thread support, which is  
    the default.
    
    Note, however, that i have not personally played with this thread- 
    safety stuff to any degree, so YMMV.
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