Fix handling SIGTERM while DRM-locked

And at the same time, clean up the signal handling in the regular
case.

https://bugzilla.gnome.org/show_bug.cgi?id=705861

src/core/main.c

@@ -60,6 +60,7 @@
 #endif
 
 #include <glib-object.h>
+#include <glib-unix.h>
 #include <gdk/gdkx.h>
 
 #include <stdlib.h>
@@ -356,59 +357,12 @@ meta_finalize (void)
 #endif
 }
 
-static int signal_pipe_fds[2] = { -1, -1 };
-
-static void
-signal_handler (int signum)
-{
-  if (signal_pipe_fds[1] >= 0)
-    {
-      switch (signum)
-        {
-        case SIGTERM:
-          write (signal_pipe_fds[1], "T", 1);
-          break;
-        default:
-          break;
-        }
-    }
-}
-
 static gboolean
-on_signal (GIOChannel *source,
+on_sigterm (gpointer user_data)
-           GIOCondition condition,
-           void *data)
 {
-  char signal;
+  meta_quit (EXIT_SUCCESS);
-  int count;
 
-  for (;;)
+  return G_SOURCE_REMOVE;
-    {
-      count = read (signal_pipe_fds[0], &signal, 1);
-      if (count == EINTR)
-        continue;
-      if (count < 0)
-        {
-          const char *msg = strerror (errno);
-          g_warning ("Error handling signal: %s", msg);
-        }
-      if (count != 1)
-        {
-          g_warning ("Unexpectedly failed to read byte from signal pipe\n");
-          return TRUE;
-        }
-      break;
-    }
-  switch (signal)
-    {
-    case 'T': /* SIGTERM */
-      meta_quit (META_EXIT_SUCCESS);
-      break;
-    default:
-      g_warning ("Spurious character '%c' read from signal pipe", signal);
-    }
-
-  return TRUE;
 }
 
 /**
@@ -422,7 +376,6 @@ meta_init (void)
 {
   struct sigaction act;
   sigset_t empty_mask;
-  GIOChannel *channel;
   
   sigemptyset (&empty_mask);
   act.sa_handler = SIG_IGN;
@@ -437,20 +390,7 @@ meta_init (void)
                 g_strerror (errno));
 #endif
 
-  if (pipe (signal_pipe_fds) != 0)
+  g_unix_signal_add (SIGTERM, on_sigterm, NULL);
-    g_printerr ("Failed to create signal pipe: %s\n",
-                g_strerror (errno));
-
-  channel = g_io_channel_unix_new (signal_pipe_fds[0]);
-  g_io_channel_set_flags (channel, G_IO_FLAG_NONBLOCK, NULL);
-  g_io_add_watch (channel, G_IO_IN, (GIOFunc) on_signal, NULL);
-  g_io_channel_set_close_on_unref (channel, TRUE);
-  g_io_channel_unref (channel);
-
-  act.sa_handler = &signal_handler;
-  if (sigaction (SIGTERM, &act, NULL) < 0)
-    g_printerr ("Failed to register SIGTERM handler: %s\n",
-		g_strerror (errno));
 
   if (g_getenv ("MUTTER_VERBOSE"))
     meta_set_verbose (TRUE);

src/wayland/meta-tty.c

@@ -64,6 +64,7 @@ struct _MetaTTY
 
   int input_source;
   GSource *vt_enter_source, *vt_leave_source;
+  GSource *nested_term;
   int vt, starting_vt;
   int kb_mode;
 };
@@ -83,7 +84,7 @@ G_DEFINE_TYPE_WITH_CODE (MetaTTY, meta_tty, G_TYPE_OBJECT,
 						meta_tty_initable_iface_init));
 
 static gboolean
-vt_acquire_handler (gpointer user_data)
+quit_nested_loop (gpointer user_data)
 {
   MetaTTY *tty = user_data;
 
@@ -300,16 +301,20 @@ meta_tty_initable_init(GInitable     *initable,
       goto err_kdmode;
     }
 
-  tty->vt_enter_source = g_unix_signal_source_new (SIGUSR2);
-  g_source_set_callback (tty->vt_enter_source, vt_acquire_handler, tty, NULL);
   tty->vt_leave_source = g_unix_signal_source_new (SIGUSR1);
   g_source_set_callback (tty->vt_leave_source, vt_release_handler, tty, NULL);
 
+  tty->vt_enter_source = g_unix_signal_source_new (SIGUSR2);
+  g_source_set_callback (tty->vt_enter_source, quit_nested_loop, tty, NULL);
+  tty->nested_term = g_unix_signal_source_new (SIGTERM);
+  g_source_set_callback (tty->nested_term, quit_nested_loop, tty, NULL);
+
   tty->nested_context = g_main_context_new ();
   tty->nested_loop = g_main_loop_new (tty->nested_context, FALSE);
 
   g_source_attach (tty->vt_leave_source, NULL);
   g_source_attach (tty->vt_enter_source, tty->nested_context);
+  g_source_attach (tty->nested_term, tty->nested_context);
 
   return TRUE;
 
@@ -364,6 +369,7 @@ meta_tty_finalize (GObject *object)
 
   g_source_destroy (tty->vt_enter_source);
   g_source_destroy (tty->vt_leave_source);
+  g_source_destroy (tty->nested_term);
 
   g_main_loop_unref (tty->nested_loop);
   g_main_context_unref (tty->nested_context);