bt: track name-owner changes via NMModemManager and create D-Bus proxy asynchronously

Fix two issues of the previous code:

  - the D-Bus proxy for the modem manager should not get created
    synchronously.
  - NMModemManager is a singleton, let it track the name-owner
    change and the D-Bus proxy, instead of having one per NMDeviceBt.

4 files changed, 198 insertions, 38 deletions

diff --git a/src/devices/bluetooth/nm-device-bt.c b/src/devices/bluetooth/nm-device-bt.c
index 86ee7f9780..3402532fca 100644
--- a/src/devices/bluetooth/nm-device-bt.c
+++ b/src/devices/bluetooth/nm-device-bt.c
@@ -64,7 +64,8 @@ enum {
 static guint signals[LAST_SIGNAL] = { 0 };
 
 typedef struct {
-	GDBusProxy *mm_proxy;
+	NMModemManager *modem_manager;
+
 	gboolean mm_running;
 
 	NMBluezDevice *bt_device;
@@ -966,9 +967,12 @@ is_available (NMDevice *dev, NMDeviceCheckDevAvailableFlags flags)
 }
 
 static void
-set_mm_running (NMDeviceBt *self, gboolean running)
+set_mm_running (NMDeviceBt *self)
 {
 	NMDeviceBtPrivate *priv = NM_DEVICE_BT_GET_PRIVATE (self);
+	gboolean running;
+
+	running = (nm_modem_manager_name_owner_get (priv->modem_manager) != NULL);
 
 	if (priv->mm_running != running) {
 		_LOGD (LOGD_BT, "ModemManager now %s",
@@ -982,21 +986,11 @@ set_mm_running (NMDeviceBt *self, gboolean running)
 }
 
 static void
-mm_name_owner_changed (NMDeviceBt *self)
-{
-	NMDeviceBtPrivate *priv = NM_DEVICE_BT_GET_PRIVATE (self);
-	gs_free char *owner = NULL;
-
-	owner = g_dbus_proxy_get_name_owner (priv->mm_proxy);
-	set_mm_running (self, owner != NULL);
-}
-
-static void
 mm_name_owner_changed_cb (GObject *object,
                           GParamSpec *pspec,
-                          NMDeviceBt *self)
+                          gpointer user_data)
 {
-	mm_name_owner_changed (self);
+	set_mm_running (user_data);
 }
 
 /*****************************************************************************/
@@ -1063,30 +1057,18 @@ constructed (GObject *object)
 	NMDeviceBt *self = NM_DEVICE_BT (object);
 	NMDeviceBtPrivate *priv = NM_DEVICE_BT_GET_PRIVATE (self);
 	const char *my_hwaddr;
-	gs_free_error GError *error = NULL;
-
-	priv->mm_proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SYSTEM,
-	                                                G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES |
-	                                                    G_DBUS_PROXY_FLAGS_DO_NOT_CONNECT_SIGNALS |
-	                                                    G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
-	                                                NULL,
-	                                                NM_MODEM_MANAGER_MM_DBUS_SERVICE,
-	                                                NM_MODEM_MANAGER_MM_DBUS_PATH,
-	                                                NM_MODEM_MANAGER_MM_DBUS_INTERFACE,
-	                                                NULL, &error);
-	if (priv->mm_proxy) {
-		g_signal_connect (priv->mm_proxy, "notify::g-name-owner",
-		                  G_CALLBACK (mm_name_owner_changed_cb),
-		                  self);
-		mm_name_owner_changed (self);
-	} else {
-		_LOGW (LOGD_MB, "Could not create proxy for '%s': %s",
-		       NM_MODEM_MANAGER_MM_DBUS_SERVICE, error->message);
-		g_clear_error (&error);
-	}
 
 	G_OBJECT_CLASS (nm_device_bt_parent_class)->constructed (object);
 
+	priv->modem_manager = g_object_ref (nm_modem_manager_get ());
+
+	nm_modem_manager_name_owner_ref (priv->modem_manager);
+
+	g_signal_connect (priv->modem_manager,
+	                  "notify::"NM_MODEM_MANAGER_NAME_OWNER,
+	                  G_CALLBACK (mm_name_owner_changed_cb),
+	                  self);
+
 	if (priv->bt_device) {
 		/* Watch for BT device property changes */
 		g_signal_connect (priv->bt_device, "notify::" NM_BLUEZ_DEVICE_CONNECTED,
@@ -1100,6 +1082,8 @@ constructed (GObject *object)
 		priv->bdaddr = g_strdup (my_hwaddr);
 	else
 		g_warn_if_reached ();
+
+	set_mm_running (self);
 }
 
 NMDevice *
@@ -1137,9 +1121,10 @@ dispose (GObject *object)
 
 	g_signal_handlers_disconnect_matched (priv->bt_device, G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, object);
 
-	if (priv->mm_proxy) {
-		g_signal_handlers_disconnect_by_func (priv->mm_proxy, G_CALLBACK (mm_name_owner_changed_cb), object);
-		g_clear_object (&priv->mm_proxy);
+	if (priv->modem_manager) {
+		g_signal_handlers_disconnect_by_func (priv->modem_manager, G_CALLBACK (mm_name_owner_changed_cb), object);
+		nm_modem_manager_name_owner_unref (priv->modem_manager);
+		g_clear_object (&priv->modem_manager);
 	}
 
 	modem_cleanup (NM_DEVICE_BT (object));
diff --git a/src/devices/wwan/libnm-wwan.ver b/src/devices/wwan/libnm-wwan.ver
index eb577aafb7..6efcb03fa7 100644
--- a/src/devices/wwan/libnm-wwan.ver
+++ b/src/devices/wwan/libnm-wwan.ver
@@ -20,7 +20,11 @@ global:
 	nm_modem_get_type;
 	nm_modem_get_uid;
 	nm_modem_ip4_pre_commit;
+	nm_modem_manager_get;
 	nm_modem_manager_get_type;
+	nm_modem_manager_name_owner_get;
+	nm_modem_manager_name_owner_ref;
+	nm_modem_manager_name_owner_unref;
 	nm_modem_owns_port;
 	nm_modem_set_mm_enabled;
 	nm_modem_stage3_ip4_config_start;
diff --git a/src/devices/wwan/nm-modem-manager.c b/src/devices/wwan/nm-modem-manager.c
index d6a515077a..b5aa60c87a 100644
--- a/src/devices/wwan/nm-modem-manager.c
+++ b/src/devices/wwan/nm-modem-manager.c
@@ -45,6 +45,10 @@
 
 /*****************************************************************************/
 
+NM_GOBJECT_PROPERTIES_DEFINE (NMModemManager,
+	PROP_NAME_OWNER,
+);
+
 enum {
 	MODEM_ADDED,
 	LAST_SIGNAL,
@@ -65,6 +69,11 @@ typedef struct {
 		gulong handle_object_added_id;
 		gulong handle_object_removed_id;
 		guint relaunch_id;
+
+		GDBusProxy *proxy;
+		GCancellable *proxy_cancellable;
+		guint proxy_ref_count;
+		char *proxy_name_owner;
 	} modm;
 
 #if WITH_OFONO
@@ -435,6 +444,129 @@ modm_schedule_manager_relaunch (NMModemManager *self,
 
 /*****************************************************************************/
 
+static void
+modm_proxy_name_owner_reset (NMModemManager *self)
+{
+	NMModemManagerPrivate *priv = NM_MODEM_MANAGER_GET_PRIVATE (self);
+	char *name = NULL;
+
+	if (priv->modm.proxy)
+		name = g_dbus_proxy_get_name_owner (priv->modm.proxy);
+
+	if (nm_streq0 (priv->modm.proxy_name_owner, name)) {
+		g_free (name);
+		return;
+	}
+	g_free (priv->modm.proxy_name_owner);
+	priv->modm.proxy_name_owner = name;
+
+	_notify (self, PROP_NAME_OWNER);
+}
+
+static void
+modm_proxy_name_owner_changed_cb (GObject    *object,
+                                  GParamSpec *pspec,
+                                  gpointer    user_data)
+{
+	modm_proxy_name_owner_reset (user_data);
+}
+
+static void
+modm_proxy_new_cb (GObject *source_object,
+                   GAsyncResult *result,
+                   gpointer user_data)
+{
+	NMModemManager *self;
+	NMModemManagerPrivate *priv;
+	GDBusProxy *proxy;
+	gs_free_error GError *error = NULL;
+
+	proxy = g_dbus_proxy_new_for_bus_finish (result, &error);
+	if (   !proxy
+	    && g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
+		return;
+
+	self = user_data;
+	priv = NM_MODEM_MANAGER_GET_PRIVATE (self);
+
+	g_clear_object (&priv->modm.proxy_cancellable);
+
+	if (!proxy) {
+		_LOGW ("could not obtain D-Bus proxy for ModemManager: %s", error->message);
+		return;
+	}
+
+	priv->modm.proxy = proxy;
+	g_signal_connect (priv->modm.proxy, "notify::g-name-owner",
+	                  G_CALLBACK (modm_proxy_name_owner_changed_cb), self);
+
+	modm_proxy_name_owner_reset (self);
+}
+
+void
+nm_modem_manager_name_owner_ref (NMModemManager *self)
+{
+	NMModemManagerPrivate *priv;
+
+	g_return_if_fail (NM_IS_MODEM_MANAGER (self));
+
+	priv = NM_MODEM_MANAGER_GET_PRIVATE (self);
+
+	if (priv->modm.proxy_ref_count++ > 0) {
+		/* only try once to create the proxy. If proxy creation
+		 * for the first "ref" failed, it's unclear what to do.
+		 * The proxy is hosed. */
+		return;
+	}
+
+	nm_assert (!priv->modm.proxy && !priv->modm.proxy_cancellable);
+
+	priv->modm.proxy_cancellable = g_cancellable_new ();
+
+	g_dbus_proxy_new_for_bus (G_BUS_TYPE_SYSTEM,
+	                            G_DBUS_PROXY_FLAGS_DO_NOT_LOAD_PROPERTIES
+	                          | G_DBUS_PROXY_FLAGS_DO_NOT_CONNECT_SIGNALS
+	                          | G_DBUS_PROXY_FLAGS_DO_NOT_AUTO_START,
+	                          NULL,
+	                          NM_MODEM_MANAGER_MM_DBUS_SERVICE,
+	                          NM_MODEM_MANAGER_MM_DBUS_PATH,
+	                          NM_MODEM_MANAGER_MM_DBUS_INTERFACE,
+	                          priv->modm.proxy_cancellable,
+	                          modm_proxy_new_cb,
+	                          self);
+}
+
+void
+nm_modem_manager_name_owner_unref (NMModemManager *self)
+{
+	NMModemManagerPrivate *priv;
+
+	g_return_if_fail (NM_IS_MODEM_MANAGER (self));
+
+	priv = NM_MODEM_MANAGER_GET_PRIVATE (self);
+
+	g_return_if_fail (priv->modm.proxy_ref_count > 0);
+
+	if (--priv->modm.proxy_ref_count > 0)
+		return;
+
+	nm_clear_g_cancellable (&priv->modm.proxy_cancellable);
+	g_clear_object (&priv->modm.proxy);
+
+	modm_proxy_name_owner_reset (self);
+}
+
+const char *
+nm_modem_manager_name_owner_get (NMModemManager *self)
+{
+	g_return_val_if_fail (NM_IS_MODEM_MANAGER (self), NULL);
+	nm_assert (NM_MODEM_MANAGER_GET_PRIVATE (self)->modm.proxy_ref_count > 0);
+
+	return NM_MODEM_MANAGER_GET_PRIVATE (self)->modm.proxy_name_owner;
+}
+
+/*****************************************************************************/
+
 #if WITH_OFONO
 
 static void
@@ -670,6 +802,25 @@ bus_get_ready (GObject *source,
 /*****************************************************************************/
 
 static void
+get_property (GObject *object, guint prop_id,
+              GValue *value, GParamSpec *pspec)
+{
+	NMModemManager *self = NM_MODEM_MANAGER (object);
+	NMModemManagerPrivate *priv = NM_MODEM_MANAGER_GET_PRIVATE (self);
+
+	switch (prop_id) {
+	case PROP_NAME_OWNER:
+		g_value_set_string (value, priv->modm.proxy_name_owner);
+		break;
+	default:
+		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+		break;
+	}
+}
+
+/*****************************************************************************/
+
+static void
 nm_modem_manager_init (NMModemManager *self)
 {
 	NMModemManagerPrivate *priv = NM_MODEM_MANAGER_GET_PRIVATE (self);
@@ -695,6 +846,10 @@ dispose (GObject *object)
 
 	nm_clear_g_source (&priv->modm.relaunch_id);
 
+	nm_clear_g_cancellable (&priv->modm.proxy_cancellable);
+	g_clear_object (&priv->modm.proxy);
+	nm_clear_g_free (&priv->modm.proxy_name_owner);
+
 	modm_clear_manager (self);
 
 #if WITH_OFONO
@@ -723,6 +878,15 @@ nm_modem_manager_class_init (NMModemManagerClass *klass)
 	GObjectClass *object_class = G_OBJECT_CLASS (klass);
 
 	object_class->dispose = dispose;
+	object_class->get_property = get_property;
+
+	obj_properties[PROP_NAME_OWNER] =
+	     g_param_spec_string (NM_MODEM_MANAGER_NAME_OWNER, "", "",
+	                          NULL,
+	                          G_PARAM_READABLE
+	                          | G_PARAM_STATIC_STRINGS);
+
+	g_object_class_install_properties (object_class, _PROPERTY_ENUMS_LAST, obj_properties);
 
 	signals[MODEM_ADDED] =
 	    g_signal_new (NM_MODEM_MANAGER_MODEM_ADDED,
diff --git a/src/devices/wwan/nm-modem-manager.h b/src/devices/wwan/nm-modem-manager.h
index 84eb232e98..5f913083a9 100644
--- a/src/devices/wwan/nm-modem-manager.h
+++ b/src/devices/wwan/nm-modem-manager.h
@@ -34,6 +34,8 @@
 
 #define NM_MODEM_MANAGER_MODEM_ADDED "modem-added"
 
+#define NM_MODEM_MANAGER_NAME_OWNER "name-owner"
+
 #define NM_MODEM_MANAGER_MM_DBUS_SERVICE   "org.freedesktop.ModemManager1"
 #define NM_MODEM_MANAGER_MM_DBUS_PATH      "/org/freedesktop/ModemManager1"
 #define NM_MODEM_MANAGER_MM_DBUS_INTERFACE "org.freedesktop.ModemManager1"
@@ -45,4 +47,9 @@ GType nm_modem_manager_get_type (void);
 
 NMModemManager *nm_modem_manager_get (void);
 
+void nm_modem_manager_name_owner_ref (NMModemManager *self);
+void nm_modem_manager_name_owner_unref (NMModemManager *self);
+
+const char *nm_modem_manager_name_owner_get (NMModemManager *self);
+
 #endif /* __NETWORKMANAGER_MODEM_MANAGER_H__ */