libmm-glib,manager: don't fail creation if the ModemManager process is not found

A 'GDBusObjectManagerClient' for a service for which there is no current
name-owner is a perfectly valid and useful object. For example, we could then
connect to the 'notify::name-owner' property to follow the life cycle of the
ModemManager process.

So, don't tie the successful creation of a 'MMManager' to the successful
creation of the internal GDBusProxy for the 'Manager1' interface. If there is
no current name owner, the GDBusProxy wouldn't be created, and instead we
would completely fail the 'MMManager' creation.

libmm-glib/mm-manager.c

@@ -42,15 +42,7 @@
  * modem objects.
  */
 
-static void initable_iface_init       (GInitableIface      *iface);
+G_DEFINE_TYPE (MMManager, mm_manager, MM_GDBUS_TYPE_OBJECT_MANAGER_CLIENT)
-static void async_initable_iface_init (GAsyncInitableIface *iface);
-
-static GInitableIface      *initable_parent_iface;
-static GAsyncInitableIface *async_initable_parent_iface;
-
-G_DEFINE_TYPE_EXTENDED (MMManager, mm_manager, MM_GDBUS_TYPE_OBJECT_MANAGER_CLIENT, 0,
-                        G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE, initable_iface_init)
-                        G_IMPLEMENT_INTERFACE (G_TYPE_ASYNC_INITABLE, async_initable_iface_init))
 
 struct _MMManagerPrivate {
   /* The proxy for the Manager interface */
@@ -95,6 +87,42 @@ get_proxy_type (GDBusObjectManagerClient *manager,
 
 /*****************************************************************************/
 
+static gboolean
+ensure_modem_manager1_proxy (MMManager  *self,
+                             GError    **error)
+{
+    gchar *name = NULL;
+    gchar *object_path = NULL;
+    GDBusObjectManagerClientFlags flags = G_DBUS_OBJECT_MANAGER_CLIENT_FLAGS_NONE;
+    GDBusConnection *connection = NULL;
+
+    if (self->priv->manager_iface_proxy)
+        return TRUE;
+
+    /* Get the Manager proxy created synchronously now */
+    g_object_get (self,
+                  "name",        &name,
+                  "object-path", &object_path,
+                  "flags",       &flags,
+                  "connection",  &connection,
+                  NULL);
+
+    self->priv->manager_iface_proxy =
+        mm_gdbus_org_freedesktop_modem_manager1_proxy_new_sync (connection,
+                                                                flags,
+                                                                name,
+                                                                object_path,
+                                                                NULL,
+                                                                error);
+    g_object_unref (connection);
+    g_free (object_path);
+    g_free (name);
+
+    return !!self->priv->manager_iface_proxy;
+}
+
+/*****************************************************************************/
+
 /**
  * mm_manager_new_finish:
  * @res: The #GAsyncResult obtained from the #GAsyncReadyCallback passed to mm_manager_new().
@@ -196,11 +224,16 @@ mm_manager_new_sync (GDBusConnection                *connection,
  *
  * Gets the #GDBusProxy interface of the @manager.
  *
- * Returns: (transfer none): The #GDBusProxy interface of @manager. Do not free the returned object, it is owned by @manager.
+ * Returns: (transfer none): The #GDBusProxy interface of @manager, or #NULL if none. Do not free the returned object, it is owned by @manager.
  */
 GDBusProxy *
 mm_manager_peek_proxy (MMManager *manager)
 {
+    g_return_val_if_fail (MM_IS_MANAGER (manager), NULL);
+
+    if (!ensure_modem_manager1_proxy (manager, NULL))
+        return NULL;
+
     return G_DBUS_PROXY (manager->priv->manager_iface_proxy);
 }
 
@@ -210,11 +243,16 @@ mm_manager_peek_proxy (MMManager *manager)
  *
  * Gets the #GDBusProxy interface of the @manager.
  *
- * Returns: (transfer full): The #GDBusProxy interface of @manager, which must be freed with g_object_unref().
+ * Returns: (transfer full): The #GDBusProxy interface of @manager, or #NULL if none. The returned object must be freed with g_object_unref().
  */
 GDBusProxy *
 mm_manager_get_proxy (MMManager *manager)
 {
+    g_return_val_if_fail (MM_IS_MANAGER (manager), NULL);
+
+    if (!ensure_modem_manager1_proxy (manager, NULL))
+        return NULL;
+
     return G_DBUS_PROXY (g_object_ref (manager->priv->manager_iface_proxy));
 }
 
@@ -282,12 +320,22 @@ mm_manager_set_logging (MMManager           *manager,
                         gpointer             user_data)
 {
     GSimpleAsyncResult *result;
+    GError *inner_error = NULL;
+
+    g_return_if_fail (MM_IS_MANAGER (manager));
 
     result = g_simple_async_result_new (G_OBJECT (manager),
                                         callback,
                                         user_data,
                                         mm_manager_set_logging);
 
+    if (!ensure_modem_manager1_proxy (manager, &inner_error)) {
+        g_simple_async_result_take_error (result, inner_error);
+        g_simple_async_result_complete_in_idle (result);
+        g_object_unref (result);
+        return;
+    }
+
     mm_gdbus_org_freedesktop_modem_manager1_call_set_logging (
         manager->priv->manager_iface_proxy,
         level,
@@ -317,6 +365,11 @@ mm_manager_set_logging_sync (MMManager     *manager,
                              GCancellable  *cancellable,
                              GError       **error)
 {
+    g_return_val_if_fail (MM_IS_MANAGER (manager), FALSE);
+
+    if (!ensure_modem_manager1_proxy (manager, error))
+        return FALSE;
+
     return (mm_gdbus_org_freedesktop_modem_manager1_call_set_logging_sync (
                 manager->priv->manager_iface_proxy,
                 level,
@@ -341,11 +394,7 @@ mm_manager_scan_devices_finish (MMManager     *manager,
                                 GAsyncResult  *res,
                                 GError       **error)
 {
-    if (g_simple_async_result_propagate_error (G_SIMPLE_ASYNC_RESULT (res),
+    return !g_simple_async_result_propagate_error (G_SIMPLE_ASYNC_RESULT (res), error);
-                                               error))
-        return FALSE;
-
-    return TRUE;
 }
 
 static void
@@ -390,12 +439,22 @@ mm_manager_scan_devices (MMManager           *manager,
                          gpointer             user_data)
 {
     GSimpleAsyncResult *result;
+    GError *inner_error = NULL;
+
+    g_return_if_fail (MM_IS_MANAGER (manager));
 
     result = g_simple_async_result_new (G_OBJECT (manager),
                                         callback,
                                         user_data,
                                         mm_manager_scan_devices);
 
+    if (!ensure_modem_manager1_proxy (manager, &inner_error)) {
+        g_simple_async_result_take_error (result, inner_error);
+        g_simple_async_result_complete_in_idle (result);
+        g_object_unref (result);
+        return;
+    }
+
     mm_gdbus_org_freedesktop_modem_manager1_call_scan_devices (
         manager->priv->manager_iface_proxy,
         cancellable,
@@ -422,6 +481,16 @@ mm_manager_scan_devices_sync (MMManager     *manager,
                               GCancellable  *cancellable,
                               GError       **error)
 {
+    g_return_val_if_fail (MM_IS_MANAGER (manager), FALSE);
+
+    if (!manager->priv->manager_iface_proxy) {
+        g_set_error (error,
+                     MM_CORE_ERROR,
+                     MM_CORE_ERROR_NOT_FOUND,
+                     "ModemManager unavailable");
+        return FALSE;
+    }
+
     return (mm_gdbus_org_freedesktop_modem_manager1_call_scan_devices_sync (
                 manager->priv->manager_iface_proxy,
                 cancellable,
@@ -430,174 +499,6 @@ mm_manager_scan_devices_sync (MMManager     *manager,
 
 /*****************************************************************************/
 
-static gboolean
-initable_init_sync (GInitable     *initable,
-                    GCancellable  *cancellable,
-                    GError       **error)
-{
-    MMManagerPrivate *priv = MM_MANAGER (initable)->priv;
-	GError *inner_error = NULL;
-    gchar *name = NULL;
-    gchar *object_path = NULL;
-    GDBusObjectManagerClientFlags flags = G_DBUS_OBJECT_MANAGER_CLIENT_FLAGS_NONE;
-    GDBusConnection *connection = NULL;
-
-	/* Chain up parent's initable callback before calling child's one */
-	if (!initable_parent_iface->init (initable, cancellable, &inner_error)) {
-		g_propagate_error (error, inner_error);
-		return FALSE;
-	}
-
-    /* Get the Manager proxy created synchronously now */
-    g_object_get (initable,
-                  "name", &name,
-                  "object-path", &object_path,
-                  "flags", &flags,
-                  "connection", &connection,
-                  NULL);
-    priv->manager_iface_proxy =
-        mm_gdbus_org_freedesktop_modem_manager1_proxy_new_sync (connection,
-                                                                flags,
-                                                                name,
-                                                                object_path,
-                                                                cancellable,
-                                                                &inner_error);
-    g_object_unref (connection);
-    g_free (object_path);
-    g_free (name);
-
-    if (!priv->manager_iface_proxy) {
-		g_propagate_error (error, inner_error);
-		return FALSE;
-    }
-
-    /* All good */
-	return TRUE;
-}
-
-/*****************************************************************************/
-
-typedef struct {
-    GSimpleAsyncResult *result;
-    int io_priority;
-    GCancellable *cancellable;
-    MMManager *manager;
-} InitAsyncContext;
-
-static void
-init_async_context_free (InitAsyncContext *ctx)
-{
-    g_object_unref (ctx->manager);
-    g_object_unref (ctx->result);
-    if (ctx->cancellable)
-        g_object_unref (ctx->cancellable);
-    g_free (ctx);
-}
-
-static gboolean
-initable_init_finish (GAsyncInitable  *initable,
-                      GAsyncResult    *result,
-                      GError         **error)
-{
-    if (g_simple_async_result_propagate_error (G_SIMPLE_ASYNC_RESULT (result),
-                                               error))
-        return FALSE;
-
-    return TRUE;
-}
-
-static void
-initable_init_async_manager_proxy_ready (GObject      *source,
-                                         GAsyncResult *res,
-                                         gpointer      user_data)
-{
-    GError *inner_error = NULL;
-    InitAsyncContext *ctx = user_data;
-    MMManagerPrivate *priv = ctx->manager->priv;
-
-    priv->manager_iface_proxy =
-        mm_gdbus_org_freedesktop_modem_manager1_proxy_new_finish (res,
-                                                                  &inner_error);
-    if (!priv->manager_iface_proxy)
-        g_simple_async_result_take_error (ctx->result, inner_error);
-    else
-        g_simple_async_result_set_op_res_gboolean (ctx->result, TRUE);
-
-    g_simple_async_result_complete (ctx->result);
-    init_async_context_free (ctx);
-}
-
-static void
-initable_init_async_parent_ready (GObject      *source,
-                                  GAsyncResult *res,
-                                  gpointer      user_data)
-{
-    GError *inner_error = NULL;
-    InitAsyncContext *ctx = user_data;
-    gchar *name = NULL;
-    gchar *object_path = NULL;
-    GDBusObjectManagerClientFlags flags = G_DBUS_OBJECT_MANAGER_CLIENT_FLAGS_NONE;
-    GDBusConnection *connection = NULL;
-
-    /* Parent init ready, check it */
-    if (!async_initable_parent_iface->init_finish (G_ASYNC_INITABLE (source),
-                                                   res,
-                                                   &inner_error)) {
-        g_simple_async_result_take_error (ctx->result, inner_error);
-        g_simple_async_result_complete (ctx->result);
-        init_async_context_free (ctx);
-        return;
-    }
-
-    /* Get the Manager proxy created asynchronously now */
-    g_object_get (ctx->manager,
-                  "name", &name,
-                  "object-path", &object_path,
-                  "flags", &flags,
-                  "connection", &connection,
-                  NULL);
-    mm_gdbus_org_freedesktop_modem_manager1_proxy_new (connection,
-                                                       flags,
-                                                       name,
-                                                       object_path,
-                                                       ctx->cancellable,
-                                                       initable_init_async_manager_proxy_ready,
-                                                       ctx);
-    g_object_unref (connection);
-    g_free (object_path);
-    g_free (name);
-}
-
-static void
-initable_init_async (GAsyncInitable      *initable,
-                     int                  io_priority,
-                     GCancellable        *cancellable,
-                     GAsyncReadyCallback  callback,
-                     gpointer             user_data)
-{
-    InitAsyncContext *ctx;
-
-    ctx = g_new (InitAsyncContext, 1);
-    ctx->manager = g_object_ref (initable);
-    ctx->result = g_simple_async_result_new (G_OBJECT (initable),
-                                             callback,
-                                             user_data,
-                                             initable_init_async);
-    ctx->cancellable = (cancellable ?
-                        g_object_ref (cancellable) :
-                        NULL);
-    ctx->io_priority = io_priority;
-
-	/* Chain up parent's initable callback before calling child's one */
-    async_initable_parent_iface->init_async (initable,
-                                             io_priority,
-                                             cancellable,
-                                             initable_init_async_parent_ready,
-                                             ctx);
-}
-
-/*****************************************************************************/
-
 static void
 register_dbus_errors (void)
 {
@@ -636,21 +537,6 @@ dispose (GObject *object)
     G_OBJECT_CLASS (mm_manager_parent_class)->dispose (object);
 }
 
-static void
-initable_iface_init (GInitableIface *iface)
-{
-    initable_parent_iface = g_type_interface_peek_parent (iface);
-	iface->init = initable_init_sync;
-}
-
-static void
-async_initable_iface_init (GAsyncInitableIface *iface)
-{
-    async_initable_parent_iface = g_type_interface_peek_parent (iface);
-	iface->init_async = initable_init_async;
-	iface->init_finish = initable_init_finish;
-}
-
 static void
 mm_manager_class_init (MMManagerClass *manager_class)
 {