gtk multithreaded apps and glib signals

["Brian J. Tarricone" <bjt23 cornell edu>]

hi all-

i'm getting a bit confused as to what i'm supposed to do to make sure 
multithreaded gtk apps don't do evil things.  i'm writing a music player 
(which is a GObject), and the audio decoding and output are handled in a 
separate thread (let's call this "thread #2").  when an audio stream 
finishes playing, i want it to send a glib signal ("stream-ended").  
obviously, thread #2 is what knows about the stream ending, and so 
logically it will call g_signal_emit().  do the signal handlers get 
called in thread #2, or in the main thread?  if in thread #2, i assume i 
have to surround any gtk calls in the signal handler with 
gdk_threads_enter/leave(), correct?
if the signals are handled in thread #2, is there a way to have the 
signal get handled in the main thread?  perhaps using g_idle_add() or 
g_timeout_add()?  in that case, do i still nead the 
gdk_threads_enter/leave() pair?
i'm just trying to figure out the best way to do this; any suggestions 
would be appreciated.
thanks,
brian