On Saturday 11 March 2006 10:22, Gus Koppel wrote: > Thomas Okken wrote: > > I would like to catch SIGINT in my GTK+ application, > > to do a graceful exit. I was looking for the GTK+ > > equivalent of XtNoticeSignal(), but I guess there > > isn't one; when I searched the archive, all I found > > was some mention of a proposed GLib extension called > > g_signal_notify() -- which looks like what I'm looking > > for, but the thread in question is 6 years old and > > nothing seems to have come of it. > > I read a few articles discussing the use of a pipe, > > with an input source to handle the "noticing the > > event" bit within the main loop. It seems like a > > kludge, but I suppose it's workable... Is this still > > the recommended approach? (I notice the GTK > > documentation is utterly silent on the whole topic.) > > Yes, this is still the recommended way. GTK+ itself doesn't support > dealing with Unix signals at all. To handle them you need to use the > Unix libc functions. They are (mostly) standardized by POSIX for about > every Unix there is. Note that Windows and other completely different > architectures have nothing comparable to Unix signals. > > The main problem is that you MUST NOT call any GTK+ or Glib function > within your signal handler. The signal may occur any time, not just when > your program sits waiting in the GTK+ main loop. It's a very bad > happening when any GTK+ functions are getting called from within a > signal handler while the program was just interrupted when being in the > middle of the execution of any other GTK+ function, i.e. opening a > dialog, drawing things or just allocating or freeing some memory. > > So there's no direct way to inform the application about a Unix signal > has been triggered and handled. You just can't send a GTK+ signal from > within the Unix signal handler, for the reason stated above. Using a > Unix pipe which is being monitored by the GTK+ main loop is a proper way > to inform the application about the Unix signal being handled. > > For a code example of how to deal with Unix signals in GTK+, see: > http://wwwtcs.inf.tu-dresden.de/~tews/Gtk/x2992.html
This is generally the best way of dealing with asynchronous (Unix) signals, but for simple cases another approach is just to set a flag of type volatile sig_atomic_t in the Unix signal handler, and then check and act on the status of the flag in the glib event loop with an idle handler set up with g_idle_add(). Chris _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
