daemon: Export objects on bus (not name) acquision

This closes a race condition where the objects might not be exported
by the time clients call methods.

Also delete the code in the "on name lost" handler - it's not going to
happen in practice (we don't allow replacement), and causes issues as
it may be run first before we get the notification that the name is
owned.  github.com/cockpit-project/storaged has some better code here
which we could copy later.

This then in turn allows us to delete the "hold"/"release"
infrastructure.  Basically the daemon will live forever in the
process.

src/daemon/main.c

@@ -42,12 +42,6 @@ static GOptionEntry opt_entries[] =
 
 static RpmostreedDaemon *rpm_ostree_daemon = NULL;
 
-static void
-on_close (RpmostreedDaemon *daemon, gpointer data)
-{
-  g_main_loop_quit (loop);
-}
-
 static void
 start_daemon (GDBusConnection *connection,
               gboolean on_messsage_bus)
@@ -66,11 +60,6 @@ start_daemon (GDBusConnection *connection,
       g_error ("%s", local_error->message);
       g_assert_not_reached ();
     }
-
-  rpmostreed_daemon_hold (rpm_ostree_daemon);
-
-  g_signal_connect (rpm_ostree_daemon, "finished",
-                    G_CALLBACK (on_close), NULL);
 }
 
 static void
@@ -79,8 +68,9 @@ on_bus_acquired (GDBusConnection *connection,
                  gpointer user_data)
 {
   g_debug ("Connected to the system bus");
-}
 
+  start_daemon (connection, TRUE);
+}
 
 static void
 on_name_acquired (GDBusConnection *connection,
@@ -88,8 +78,6 @@ on_name_acquired (GDBusConnection *connection,
                   gpointer user_data)
 {
   g_debug ("Acquired the name %s on the system bus", name);
-
-  start_daemon (connection, TRUE);
 }
 
 static void
@@ -97,17 +85,6 @@ on_name_lost (GDBusConnection *connection,
               const char *name,
               gpointer user_data)
 {
-  g_critical ("Lost (or failed to acquire) the "
-              "name %s on the system bus", name);
-
-  if (rpm_ostree_daemon == NULL)
-    {
-      g_main_loop_quit (loop);
-    }
-  else
-    {
-      rpmostreed_daemon_release (rpm_ostree_daemon);
-    }
 }
 
 static void

src/daemon/rpmostreed-daemon.c

@@ -33,13 +33,6 @@
  * Object holding all global state.
  */
 
-enum {
-  FINISHED,
-  NUM_SIGNALS
-};
-
-static guint signals[NUM_SIGNALS];
-
 typedef struct _RpmostreedDaemonClass RpmostreedDaemonClass;
 
 /**
@@ -274,12 +267,6 @@ rpmostreed_daemon_class_init (RpmostreedDaemonClass *klass)
                                                          G_PARAM_WRITABLE |
                                                          G_PARAM_CONSTRUCT_ONLY |
                                                          G_PARAM_STATIC_STRINGS));
-
-  signals[FINISHED] = g_signal_new ("finished",
-                                    RPMOSTREED_TYPE_DAEMON,
-                                    G_SIGNAL_RUN_LAST,
-                                    0, NULL, NULL, NULL,
-                                    G_TYPE_NONE, 0);
 }
 
 static void
@@ -300,21 +287,6 @@ rpmostreed_daemon_get (void)
   return _daemon_instance;
 }
 
-void
-rpmostreed_daemon_hold (RpmostreedDaemon *self)
-{
-  self->use_count++;
-}
-
-void
-rpmostreed_daemon_release (RpmostreedDaemon *self)
-{
-  self->use_count--;
-
-  if (self->use_count == 0)
-    g_signal_emit (self, signals[FINISHED], 0);
-}
-
 void
 rpmostreed_daemon_publish (RpmostreedDaemon *self,
                            const gchar *path,

src/daemon/rpmostreed-daemon.h

@@ -29,8 +29,6 @@
 
 GType              rpmostreed_daemon_get_type       (void) G_GNUC_CONST;
 RpmostreedDaemon * rpmostreed_daemon_get            (void);
-void               rpmostreed_daemon_hold           (RpmostreedDaemon *self);
-void               rpmostreed_daemon_release        (RpmostreedDaemon *self);
 void               rpmostreed_daemon_publish        (RpmostreedDaemon *self,
                                                      const gchar *path,
                                                      gboolean uniquely,