deadlock

[Dirk Huenniger <dhun astro uni-bonn de>]

Hello everybody,
My name is Dirk, I'm writing a control programm for a 1m telescope in
Germany. The current status of the device is periodically displayed in GTK 
using a thread. When the user clicks the quit butten a callback routine is
started. At the same time  my thread does a gtk_threads_enter(). But it 
cannot enter because the callback is running so it waits inside the gtk_threads_enter
routine. My callback routine askes the thread to quit and waits for that
to happen. But the thread cannot react because it is waiting inside 
gtk_threads_enter(). So everything is hanging now. I also
tried to quit my thread in a routine added with gtk_quit_add, it did not
help. But the following evil hack worked:

/* my callback routine*/
menu_exit                              (GtkMenuItem     *menuitem,
                                        gpointer         user_data)
{
  gdk_threads_leave(); /* give back gdk "semaphore" ?????*/
  thread_stop();       /* let thread take it  and give it back*/
  gdk_threads_enter(); /* take it again*/
}

Is there any better solution to this problem?
Yours
  Dirk