GDBusConnection

GDBusConnection — D-Bus Connections

Synopsis

#include <gio/gio.h>

enum                GBusType;
void                g_bus_get                           (GBusType bus_type,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);
GDBusConnection *   g_bus_get_finish                    (GAsyncResult *res,
                                                         GError **error);
GDBusConnection *   g_bus_get_sync                      (GBusType bus_type,
                                                         GCancellable *cancellable,
                                                         GError **error);
                    GDBusConnection;
enum                GDBusConnectionFlags;
void                g_dbus_connection_new               (GIOStream *stream,
                                                         const gchar *guid,
                                                         GDBusConnectionFlags flags,
                                                         GDBusAuthObserver *observer,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);
GDBusConnection *   g_dbus_connection_new_finish        (GAsyncResult *res,
                                                         GError **error);
GDBusConnection *   g_dbus_connection_new_sync          (GIOStream *stream,
                                                         const gchar *guid,
                                                         GDBusConnectionFlags flags,
                                                         GDBusAuthObserver *observer,
                                                         GCancellable *cancellable,
                                                         GError **error);
void                g_dbus_connection_new_for_address   (const gchar *address,
                                                         GDBusConnectionFlags flags,
                                                         GDBusAuthObserver *observer,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);
GDBusConnection *   g_dbus_connection_new_for_address_finish
                                                        (GAsyncResult *res,
                                                         GError **error);
GDBusConnection *   g_dbus_connection_new_for_address_sync
                                                        (const gchar *address,
                                                         GDBusConnectionFlags flags,
                                                         GDBusAuthObserver *observer,
                                                         GCancellable *cancellable,
                                                         GError **error);
void                g_dbus_connection_start_message_processing
                                                        (GDBusConnection *connection);
void                g_dbus_connection_close             (GDBusConnection *connection,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);
gboolean            g_dbus_connection_close_finish      (GDBusConnection *connection,
                                                         GAsyncResult *res,
                                                         GError **error);
gboolean            g_dbus_connection_close_sync        (GDBusConnection *connection,
                                                         GCancellable *cancellable,
                                                         GError **error);
gboolean            g_dbus_connection_is_closed         (GDBusConnection *connection);
void                g_dbus_connection_flush             (GDBusConnection *connection,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);
gboolean            g_dbus_connection_flush_finish      (GDBusConnection *connection,
                                                         GAsyncResult *res,
                                                         GError **error);
gboolean            g_dbus_connection_flush_sync        (GDBusConnection *connection,
                                                         GCancellable *cancellable,
                                                         GError **error);
gboolean            g_dbus_connection_get_exit_on_close (GDBusConnection *connection);
void                g_dbus_connection_set_exit_on_close (GDBusConnection *connection,
                                                         gboolean exit_on_close);
GIOStream *         g_dbus_connection_get_stream        (GDBusConnection *connection);
const gchar *       g_dbus_connection_get_guid          (GDBusConnection *connection);
const gchar *       g_dbus_connection_get_unique_name   (GDBusConnection *connection);
enum                GDBusCapabilityFlags;
GDBusCapabilityFlags g_dbus_connection_get_capabilities (GDBusConnection *connection);
GCredentials *      g_dbus_connection_get_peer_credentials
                                                        (GDBusConnection *connection);
enum                GDBusCallFlags;
void                g_dbus_connection_call              (GDBusConnection *connection,
                                                         const gchar *bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         const GVariantType *reply_type,
                                                         GDBusCallFlags flags,
                                                         gint timeout_msec,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);
GVariant *          g_dbus_connection_call_finish       (GDBusConnection *connection,
                                                         GAsyncResult *res,
                                                         GError **error);
GVariant *          g_dbus_connection_call_sync         (GDBusConnection *connection,
                                                         const gchar *bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         const GVariantType *reply_type,
                                                         GDBusCallFlags flags,
                                                         gint timeout_msec,
                                                         GCancellable *cancellable,
                                                         GError **error);
void                g_dbus_connection_call_with_unix_fd_list
                                                        (GDBusConnection *connection,
                                                         const gchar *bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         const GVariantType *reply_type,
                                                         GDBusCallFlags flags,
                                                         gint timeout_msec,
                                                         GUnixFDList *fd_list,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);
GVariant *          g_dbus_connection_call_with_unix_fd_list_finish
                                                        (GDBusConnection *connection,
                                                         GUnixFDList **out_fd_list,
                                                         GAsyncResult *res,
                                                         GError **error);
GVariant *          g_dbus_connection_call_with_unix_fd_list_sync
                                                        (GDBusConnection *connection,
                                                         const gchar *bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         const GVariantType *reply_type,
                                                         GDBusCallFlags flags,
                                                         gint timeout_msec,
                                                         GUnixFDList *fd_list,
                                                         GUnixFDList **out_fd_list,
                                                         GCancellable *cancellable,
                                                         GError **error);
gboolean            g_dbus_connection_emit_signal       (GDBusConnection *connection,
                                                         const gchar *destination_bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *signal_name,
                                                         GVariant *parameters,
                                                         GError **error);
enum                GDBusSignalFlags;
void                (*GDBusSignalCallback)              (GDBusConnection *connection,
                                                         const gchar *sender_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *signal_name,
                                                         GVariant *parameters,
                                                         gpointer user_data);
guint               g_dbus_connection_signal_subscribe  (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *interface_name,
                                                         const gchar *member,
                                                         const gchar *object_path,
                                                         const gchar *arg0,
                                                         GDBusSignalFlags flags,
                                                         GDBusSignalCallback callback,
                                                         gpointer user_data,
                                                         GDestroyNotify user_data_free_func);
void                g_dbus_connection_signal_unsubscribe
                                                        (GDBusConnection *connection,
                                                         guint subscription_id);
enum                GDBusSendMessageFlags;
gboolean            g_dbus_connection_send_message      (GDBusConnection *connection,
                                                         GDBusMessage *message,
                                                         GDBusSendMessageFlags flags,
                                                         volatile guint32 *out_serial,
                                                         GError **error);
void                g_dbus_connection_send_message_with_reply
                                                        (GDBusConnection *connection,
                                                         GDBusMessage *message,
                                                         GDBusSendMessageFlags flags,
                                                         gint timeout_msec,
                                                         volatile guint32 *out_serial,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);
GDBusMessage *      g_dbus_connection_send_message_with_reply_finish
                                                        (GDBusConnection *connection,
                                                         GAsyncResult *res,
                                                         GError **error);
GDBusMessage *      g_dbus_connection_send_message_with_reply_sync
                                                        (GDBusConnection *connection,
                                                         GDBusMessage *message,
                                                         GDBusSendMessageFlags flags,
                                                         gint timeout_msec,
                                                         volatile guint32 *out_serial,
                                                         GCancellable *cancellable,
                                                         GError **error);
GDBusMessage *      (*GDBusMessageFilterFunction)       (GDBusConnection *connection,
                                                         GDBusMessage *message,
                                                         gboolean incoming,
                                                         gpointer user_data);
guint               g_dbus_connection_add_filter        (GDBusConnection *connection,
                                                         GDBusMessageFilterFunction filter_function,
                                                         gpointer user_data,
                                                         GDestroyNotify user_data_free_func);
void                g_dbus_connection_remove_filter     (GDBusConnection *connection,
                                                         guint filter_id);
                    GDBusInterfaceVTable;
void                (*GDBusInterfaceMethodCallFunc)     (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         GDBusMethodInvocation *invocation,
                                                         gpointer user_data);
GVariant *          (*GDBusInterfaceGetPropertyFunc)    (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *property_name,
                                                         GError **error,
                                                         gpointer user_data);
gboolean            (*GDBusInterfaceSetPropertyFunc)    (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *property_name,
                                                         GVariant *value,
                                                         GError **error,
                                                         gpointer user_data);
guint               g_dbus_connection_register_object   (GDBusConnection *connection,
                                                         const gchar *object_path,
                                                         GDBusInterfaceInfo *interface_info,
                                                         const GDBusInterfaceVTable *vtable,
                                                         gpointer user_data,
                                                         GDestroyNotify user_data_free_func,
                                                         GError **error);
gboolean            g_dbus_connection_unregister_object (GDBusConnection *connection,
                                                         guint registration_id);
                    GDBusSubtreeVTable;
gchar **            (*GDBusSubtreeEnumerateFunc)        (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         gpointer user_data);
GDBusInterfaceInfo ** (*GDBusSubtreeIntrospectFunc)     (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *node,
                                                         gpointer user_data);
const GDBusInterfaceVTable * (*GDBusSubtreeDispatchFunc)
                                                        (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *node,
                                                         gpointer *out_user_data,
                                                         gpointer user_data);
enum                GDBusSubtreeFlags;
guint               g_dbus_connection_register_subtree  (GDBusConnection *connection,
                                                         const gchar *object_path,
                                                         const GDBusSubtreeVTable *vtable,
                                                         GDBusSubtreeFlags flags,
                                                         gpointer user_data,
                                                         GDestroyNotify user_data_free_func,
                                                         GError **error);
gboolean            g_dbus_connection_unregister_subtree
                                                        (GDBusConnection *connection,
                                                         guint registration_id);

Object Hierarchy

  GObject
   +----GDBusConnection

Implemented Interfaces

GDBusConnection implements GInitable and GAsyncInitable.

Properties

  "address"                  gchar*                : Write / Construct Only
  "authentication-observer"  GDBusAuthObserver*    : Write / Construct Only
  "capabilities"             GDBusCapabilityFlags  : Read
  "closed"                   gboolean              : Read
  "exit-on-close"            gboolean              : Read / Write
  "flags"                    GDBusConnectionFlags  : Write / Construct Only
  "guid"                     gchar*                : Read / Write / Construct Only
  "stream"                   GIOStream*            : Read / Write / Construct Only
  "unique-name"              gchar*                : Read

Signals

  "closed"                                         : Run Last

Description

The GDBusConnection type is used for D-Bus connections to remote peers such as a message buses. It is a low-level API that offers a lot of flexibility. For instance, it lets you establish a connection over any transport that can by represented as an GIOStream.

This class is rarely used directly in D-Bus clients. If you are writing an D-Bus client, it is often easier to use the g_bus_own_name(), g_bus_watch_name() or g_dbus_proxy_new_for_bus() APIs.

As an exception to the usual GLib rule that a particular object must not be used by two threads at the same time, GDBusConnection's methods may be called from any thread[1].

Most of the ways to obtain a GDBusConnection automatically initialize it (i.e. connect to D-Bus): for instance, g_dbus_connection_new() and g_bus_get(), and the synchronous versions of those methods, give you an initialized connection. Language bindings for GIO should use g_initable_new() or g_async_initable_new_async(), which also initialize the connection.

If you construct an uninitialized GDBusConnection, such as via g_object_new(), you must initialize it via g_initable_init() or g_async_initable_init_async() before using its methods or properties. Calling methods or accessing properties on a GDBusConnection that has not completed initialization successfully is considered to be invalid, and leads to undefined behaviour. In particular, if initialization fails with a GError, the only valid thing you can do with that GDBusConnection is to free it with g_object_unref().

Example 2. D-Bus server example

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#include <gio/gio.h>
#include <stdlib.h>

#ifdef G_OS_UNIX
#include <gio/gunixfdlist.h>
/* For STDOUT_FILENO */
#include <unistd.h>
#endif

/* ---------------------------------------------------------------------------------------------------- */

static GDBusNodeInfo *introspection_data = NULL;

/* Introspection data for the service we are exporting */
static const gchar introspection_xml[] =
  "<node>"
  "  <interface name='org.gtk.GDBus.TestInterface'>"
  "    <annotation name='org.gtk.GDBus.Annotation' value='OnInterface'/>"
  "    <annotation name='org.gtk.GDBus.Annotation' value='AlsoOnInterface'/>"
  "    <method name='HelloWorld'>"
  "      <annotation name='org.gtk.GDBus.Annotation' value='OnMethod'/>"
  "      <arg type='s' name='greeting' direction='in'/>"
  "      <arg type='s' name='response' direction='out'/>"
  "    </method>"
  "    <method name='EmitSignal'>"
  "      <arg type='d' name='speed_in_mph' direction='in'>"
  "        <annotation name='org.gtk.GDBus.Annotation' value='OnArg'/>"
  "      </arg>"
  "    </method>"
  "    <method name='GimmeStdout'/>"
  "    <signal name='VelocityChanged'>"
  "      <annotation name='org.gtk.GDBus.Annotation' value='Onsignal'/>"
  "      <arg type='d' name='speed_in_mph'/>"
  "      <arg type='s' name='speed_as_string'>"
  "        <annotation name='org.gtk.GDBus.Annotation' value='OnArg_NonFirst'/>"
  "      </arg>"
  "    </signal>"
  "    <property type='s' name='FluxCapicitorName' access='read'>"
  "      <annotation name='org.gtk.GDBus.Annotation' value='OnProperty'>"
  "        <annotation name='org.gtk.GDBus.Annotation' value='OnAnnotation_YesThisIsCrazy'/>"
  "      </annotation>"
  "    </property>"
  "    <property type='s' name='Title' access='readwrite'/>"
  "    <property type='s' name='ReadingAlwaysThrowsError' access='read'/>"
  "    <property type='s' name='WritingAlwaysThrowsError' access='readwrite'/>"
  "    <property type='s' name='OnlyWritable' access='write'/>"
  "    <property type='s' name='Foo' access='read'/>"
  "    <property type='s' name='Bar' access='read'/>"
  "  </interface>"
  "</node>";

/* ---------------------------------------------------------------------------------------------------- */

static void
handle_method_call (GDBusConnection       *connection,
                    const gchar           *sender,
                    const gchar           *object_path,
                    const gchar           *interface_name,
                    const gchar           *method_name,
                    GVariant              *parameters,
                    GDBusMethodInvocation *invocation,
                    gpointer               user_data)
{
  if (g_strcmp0 (method_name, "HelloWorld") == 0)
    {
      const gchar *greeting;

      g_variant_get (parameters, "(&s)", &greeting);

      if (g_strcmp0 (greeting, "Return Unregistered") == 0)
        {
          g_dbus_method_invocation_return_error (invocation,
                                                 G_IO_ERROR,
                                                 G_IO_ERROR_FAILED_HANDLED,
                                                 "As requested, here's a GError not registered (G_IO_ERROR_FAILED_HANDLED)");
        }
      else if (g_strcmp0 (greeting, "Return Registered") == 0)
        {
          g_dbus_method_invocation_return_error (invocation,
                                                 G_DBUS_ERROR,
                                                 G_DBUS_ERROR_MATCH_RULE_NOT_FOUND,
                                                 "As requested, here's a GError that is registered (G_DBUS_ERROR_MATCH_RULE_NOT_FOUND)");
        }
      else if (g_strcmp0 (greeting, "Return Raw") == 0)
        {
          g_dbus_method_invocation_return_dbus_error (invocation,
                                                      "org.gtk.GDBus.SomeErrorName",
                                                      "As requested, here's a raw D-Bus error");
        }
      else
        {
          gchar *response;
          response = g_strdup_printf ("You greeted me with '%s'. Thanks!", greeting);
          g_dbus_method_invocation_return_value (invocation,
                                                 g_variant_new ("(s)", response));
          g_free (response);
        }
    }
  else if (g_strcmp0 (method_name, "EmitSignal") == 0)
    {
      GError *local_error;
      gdouble speed_in_mph;
      gchar *speed_as_string;

      g_variant_get (parameters, "(d)", &speed_in_mph);
      speed_as_string = g_strdup_printf ("%g mph!", speed_in_mph);

      local_error = NULL;
      g_dbus_connection_emit_signal (connection,
                                     NULL,
                                     object_path,
                                     interface_name,
                                     "VelocityChanged",
                                     g_variant_new ("(ds)",
                                                    speed_in_mph,
                                                    speed_as_string),
                                     &local_error);
      g_assert_no_error (local_error);
      g_free (speed_as_string);

      g_dbus_method_invocation_return_value (invocation, NULL);
    }
  else if (g_strcmp0 (method_name, "GimmeStdout") == 0)
    {
#ifdef G_OS_UNIX
      if (g_dbus_connection_get_capabilities (connection) & G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING)
        {
          GDBusMessage *reply;
          GUnixFDList *fd_list;
          GError *error;

          fd_list = g_unix_fd_list_new ();
          error = NULL;
          g_unix_fd_list_append (fd_list, STDOUT_FILENO, &error);
          g_assert_no_error (error);

          reply = g_dbus_message_new_method_reply (g_dbus_method_invocation_get_message (invocation));
          g_dbus_message_set_unix_fd_list (reply, fd_list);

          error = NULL;
          g_dbus_connection_send_message (connection,
                                          reply,
                                          G_DBUS_SEND_MESSAGE_FLAGS_NONE,
                                          NULL, /* out_serial */
                                          &error);
          g_assert_no_error (error);

          g_object_unref (invocation);
          g_object_unref (fd_list);
          g_object_unref (reply);
        }
      else
        {
          g_dbus_method_invocation_return_dbus_error (invocation,
                                                      "org.gtk.GDBus.Failed",
                                                      "Your message bus daemon does not support file descriptor passing (need D-Bus >= 1.3.0)");
        }
#else
      g_dbus_method_invocation_return_dbus_error (invocation,
                                                  "org.gtk.GDBus.NotOnUnix",
                                                  "Your OS does not support file descriptor passing");
#endif
    }
}

static gchar *_global_title = NULL;

static gboolean swap_a_and_b = FALSE;

static GVariant *
handle_get_property (GDBusConnection  *connection,
                     const gchar      *sender,
                     const gchar      *object_path,
                     const gchar      *interface_name,
                     const gchar      *property_name,
                     GError          **error,
                     gpointer          user_data)
{
  GVariant *ret;

  ret = NULL;
  if (g_strcmp0 (property_name, "FluxCapicitorName") == 0)
    {
      ret = g_variant_new_string ("DeLorean");
    }
  else if (g_strcmp0 (property_name, "Title") == 0)
    {
      if (_global_title == NULL)
        _global_title = g_strdup ("Back To C!");
      ret = g_variant_new_string (_global_title);
    }
  else if (g_strcmp0 (property_name, "ReadingAlwaysThrowsError") == 0)
    {
      g_set_error (error,
                   G_IO_ERROR,
                   G_IO_ERROR_FAILED,
                   "Hello %s. I thought I said reading this property "
                   "always results in an error. kthxbye",
                   sender);
    }
  else if (g_strcmp0 (property_name, "WritingAlwaysThrowsError") == 0)
    {
      ret = g_variant_new_string ("There's no home like home");
    }
  else if (g_strcmp0 (property_name, "Foo") == 0)
    {
      ret = g_variant_new_string (swap_a_and_b ? "Tock" : "Tick");
    }
  else if (g_strcmp0 (property_name, "Bar") == 0)
    {
      ret = g_variant_new_string (swap_a_and_b ? "Tick" : "Tock");
    }

  return ret;
}

static gboolean
handle_set_property (GDBusConnection  *connection,
                     const gchar      *sender,
                     const gchar      *object_path,
                     const gchar      *interface_name,
                     const gchar      *property_name,
                     GVariant         *value,
                     GError          **error,
                     gpointer          user_data)
{
  if (g_strcmp0 (property_name, "Title") == 0)
    {
      if (g_strcmp0 (_global_title, g_variant_get_string (value, NULL)) != 0)
        {
          GVariantBuilder *builder;
          GError *local_error;

          g_free (_global_title);
          _global_title = g_variant_dup_string (value, NULL);

          local_error = NULL;
          builder = g_variant_builder_new (G_VARIANT_TYPE_ARRAY);
          g_variant_builder_add (builder,
                                 "{sv}",
                                 "Title",
                                 g_variant_new_string (_global_title));
          g_dbus_connection_emit_signal (connection,
                                         NULL,
                                         object_path,
                                         "org.freedesktop.DBus.Properties",
                                         "PropertiesChanged",
                                         g_variant_new ("(sa{sv}as)",
                                                        interface_name,
                                                        builder,
                                                        NULL),
                                         &local_error);
          g_assert_no_error (local_error);
        }
    }
  else if (g_strcmp0 (property_name, "ReadingAlwaysThrowsError") == 0)
    {
      /* do nothing - they can't read it after all! */
    }
  else if (g_strcmp0 (property_name, "WritingAlwaysThrowsError") == 0)
    {
      g_set_error (error,
                   G_IO_ERROR,
                   G_IO_ERROR_FAILED,
                   "Hello AGAIN %s. I thought I said writing this property "
                   "always results in an error. kthxbye",
                   sender);
    }

  return *error == NULL;
}


/* for now */
static const GDBusInterfaceVTable interface_vtable =
{
  handle_method_call,
  handle_get_property,
  handle_set_property
};

/* ---------------------------------------------------------------------------------------------------- */

static gboolean
on_timeout_cb (gpointer user_data)
{
  GDBusConnection *connection = G_DBUS_CONNECTION (user_data);
  GVariantBuilder *builder;
  GVariantBuilder *invalidated_builder;
  GError *error;

  swap_a_and_b = !swap_a_and_b;

  error = NULL;
  builder = g_variant_builder_new (G_VARIANT_TYPE_ARRAY);
  invalidated_builder = g_variant_builder_new (G_VARIANT_TYPE ("as"));
  g_variant_builder_add (builder,
                         "{sv}",
                         "Foo",
                         g_variant_new_string (swap_a_and_b ? "Tock" : "Tick"));
  g_variant_builder_add (builder,
                         "{sv}",
                         "Bar",
                         g_variant_new_string (swap_a_and_b ? "Tick" : "Tock"));
  g_dbus_connection_emit_signal (connection,
                                 NULL,
                                 "/org/gtk/GDBus/TestObject",
                                 "org.freedesktop.DBus.Properties",
                                 "PropertiesChanged",
                                 g_variant_new ("(sa{sv}as)",
                                                "org.gtk.GDBus.TestInterface",
                                                builder,
                                                invalidated_builder),
                                 &error);
  g_assert_no_error (error);


  return TRUE;
}

/* ---------------------------------------------------------------------------------------------------- */

static void
on_bus_acquired (GDBusConnection *connection,
                 const gchar     *name,
                 gpointer         user_data)
{
  guint registration_id;

  registration_id = g_dbus_connection_register_object (connection,
                                                       "/org/gtk/GDBus/TestObject",
                                                       introspection_data->interfaces[0],
                                                       &interface_vtable,
                                                       NULL,  /* user_data */
                                                       NULL,  /* user_data_free_func */
                                                       NULL); /* GError** */
  g_assert (registration_id > 0);

  /* swap value of properties Foo and Bar every two seconds */
  g_timeout_add_seconds (2,
                         on_timeout_cb,
                         connection);
}

static void
on_name_acquired (GDBusConnection *connection,
                  const gchar     *name,
                  gpointer         user_data)
{
}

static void
on_name_lost (GDBusConnection *connection,
              const gchar     *name,
              gpointer         user_data)
{
  exit (1);
}

int
main (int argc, char *argv[])
{
  guint owner_id;
  GMainLoop *loop;

  g_type_init ();

  /* We are lazy here - we don't want to manually provide
   * the introspection data structures - so we just build
   * them from XML.
   */
  introspection_data = g_dbus_node_info_new_for_xml (introspection_xml, NULL);
  g_assert (introspection_data != NULL);

  owner_id = g_bus_own_name (G_BUS_TYPE_SESSION,
                             "org.gtk.GDBus.TestServer",
                             G_BUS_NAME_OWNER_FLAGS_NONE,
                             on_bus_acquired,
                             on_name_acquired,
                             on_name_lost,
                             NULL,
                             NULL);

  loop = g_main_loop_new (NULL, FALSE);
  g_main_loop_run (loop);

  g_bus_unown_name (owner_id);

  g_dbus_node_info_unref (introspection_data);

  return 0;
}


Example 3. D-Bus subtree example

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#include <gio/gio.h>
#include <stdlib.h>
#include <string.h>

/* ---------------------------------------------------------------------------------------------------- */

static GDBusNodeInfo *introspection_data = NULL;
static GDBusInterfaceInfo *manager_interface_info = NULL;
static GDBusInterfaceInfo *block_interface_info = NULL;
static GDBusInterfaceInfo *partition_interface_info = NULL;

/* Introspection data for the service we are exporting */
static const gchar introspection_xml[] =
  "<node>"
  "  <interface name='org.gtk.GDBus.Example.Manager'>"
  "    <method name='Hello'>"
  "      <arg type='s' name='greeting' direction='in'/>"
  "      <arg type='s' name='response' direction='out'/>"
  "    </method>"
  "  </interface>"
  "  <interface name='org.gtk.GDBus.Example.Block'>"
  "    <method name='Hello'>"
  "      <arg type='s' name='greeting' direction='in'/>"
  "      <arg type='s' name='response' direction='out'/>"
  "    </method>"
  "    <property type='i' name='Major' access='read'/>"
  "    <property type='i' name='Minor' access='read'/>"
  "    <property type='s' name='Notes' access='readwrite'/>"
  "  </interface>"
  "  <interface name='org.gtk.GDBus.Example.Partition'>"
  "    <method name='Hello'>"
  "      <arg type='s' name='greeting' direction='in'/>"
  "      <arg type='s' name='response' direction='out'/>"
  "    </method>"
  "    <property type='i' name='PartitionNumber' access='read'/>"
  "    <property type='s' name='Notes' access='readwrite'/>"
  "  </interface>"
  "</node>";

/* ---------------------------------------------------------------------------------------------------- */

static void
manager_method_call (GDBusConnection       *connection,
                     const gchar           *sender,
                     const gchar           *object_path,
                     const gchar           *interface_name,
                     const gchar           *method_name,
                     GVariant              *parameters,
                     GDBusMethodInvocation *invocation,
                     gpointer               user_data)
{
  const gchar *greeting;
  gchar *response;

  g_assert_cmpstr (interface_name, ==, "org.gtk.GDBus.Example.Manager");
  g_assert_cmpstr (method_name, ==, "Hello");

  g_variant_get (parameters, "(&s)", &greeting);

  response = g_strdup_printf ("Method %s.%s with user_data `%s' on object path %s called with arg '%s'",
                              interface_name,
                              method_name,
                              (const gchar *) user_data,
                              object_path,
                              greeting);
  g_dbus_method_invocation_return_value (invocation,
                                         g_variant_new ("(s)", response));
  g_free (response);
}

const GDBusInterfaceVTable manager_vtable =
{
  manager_method_call,
  NULL,                 /* get_property */
  NULL                  /* set_property */
};

/* ---------------------------------------------------------------------------------------------------- */

static void
block_method_call (GDBusConnection       *connection,
                   const gchar           *sender,
                   const gchar           *object_path,
                   const gchar           *interface_name,
                   const gchar           *method_name,
                   GVariant              *parameters,
                   GDBusMethodInvocation *invocation,
                   gpointer               user_data)
{
  g_assert_cmpstr (interface_name, ==, "org.gtk.GDBus.Example.Block");

  if (g_strcmp0 (method_name, "Hello") == 0)
    {
      const gchar *greeting;
      gchar *response;

      g_variant_get (parameters, "(&s)", &greeting);

      response = g_strdup_printf ("Method %s.%s with user_data `%s' on object path %s called with arg '%s'",
                                  interface_name,
                                  method_name,
                                  (const gchar *) user_data,
                                  object_path,
                                  greeting);
      g_dbus_method_invocation_return_value (invocation,
                                             g_variant_new ("(s)", response));
      g_free (response);
    }
  else if (g_strcmp0 (method_name, "DoStuff") == 0)
    {
      g_dbus_method_invocation_return_dbus_error (invocation,
                                                  "org.gtk.GDBus.TestSubtree.Error.Failed",
                                                  "This method intentionally always fails");
    }
  else
    {
      g_assert_not_reached ();
    }
}

static GVariant *
block_get_property (GDBusConnection  *connection,
                    const gchar      *sender,
                    const gchar      *object_path,
                    const gchar      *interface_name,
                    const gchar      *property_name,
                    GError          **error,
                    gpointer          user_data)
{
  GVariant *ret;
  const gchar *node;
  gint major;
  gint minor;

  node = strrchr (object_path, '/') + 1;
  if (g_str_has_prefix (node, "sda"))
    major = 8;
  else
    major = 9;
  if (strlen (node) == 4)
    minor = node[3] - '0';
  else
    minor = 0;

  ret = NULL;
  if (g_strcmp0 (property_name, "Major") == 0)
    {
      ret = g_variant_new_int32 (major);
    }
  else if (g_strcmp0 (property_name, "Minor") == 0)
    {
      ret = g_variant_new_int32 (minor);
    }
  else if (g_strcmp0 (property_name, "Notes") == 0)
    {
      g_set_error (error,
                   G_IO_ERROR,
                   G_IO_ERROR_FAILED,
                   "Hello %s. I thought I said reading this property "
                   "always results in an error. kthxbye",
                   sender);
    }
  else
    {
      g_assert_not_reached ();
    }

  return ret;
}

static gboolean
block_set_property (GDBusConnection  *connection,
                    const gchar      *sender,
                    const gchar      *object_path,
                    const gchar      *interface_name,
                    const gchar      *property_name,
                    GVariant         *value,
                    GError          **error,
                    gpointer          user_data)
{
  /* TODO */
  g_assert_not_reached ();
}

const GDBusInterfaceVTable block_vtable =
{
  block_method_call,
  block_get_property,
  block_set_property,
};

/* ---------------------------------------------------------------------------------------------------- */

static void
partition_method_call (GDBusConnection       *connection,
                       const gchar           *sender,
                       const gchar           *object_path,
                       const gchar           *interface_name,
                       const gchar           *method_name,
                       GVariant              *parameters,
                       GDBusMethodInvocation *invocation,
                       gpointer               user_data)
{
  const gchar *greeting;
  gchar *response;

  g_assert_cmpstr (interface_name, ==, "org.gtk.GDBus.Example.Partition");
  g_assert_cmpstr (method_name, ==, "Hello");

  g_variant_get (parameters, "(&s)", &greeting);

  response = g_strdup_printf ("Method %s.%s with user_data `%s' on object path %s called with arg '%s'",
                              interface_name,
                              method_name,
                              (const gchar *) user_data,
                              object_path,
                              greeting);
  g_dbus_method_invocation_return_value (invocation,
                                         g_variant_new ("(s)", response));
  g_free (response);
}

const GDBusInterfaceVTable partition_vtable =
{
  partition_method_call,
  //partition_get_property,
  //partition_set_property
};

/* ---------------------------------------------------------------------------------------------------- */

static gchar **
subtree_enumerate (GDBusConnection       *connection,
                   const gchar           *sender,
                   const gchar           *object_path,
                   gpointer               user_data)
{
  gchar **nodes;
  GPtrArray *p;

  p = g_ptr_array_new ();
  g_ptr_array_add (p, g_strdup ("sda"));
  g_ptr_array_add (p, g_strdup ("sda1"));
  g_ptr_array_add (p, g_strdup ("sda2"));
  g_ptr_array_add (p, g_strdup ("sda3"));
  g_ptr_array_add (p, g_strdup ("sdb"));
  g_ptr_array_add (p, g_strdup ("sdb1"));
  g_ptr_array_add (p, g_strdup ("sdc"));
  g_ptr_array_add (p, g_strdup ("sdc1"));
  g_ptr_array_add (p, NULL);
  nodes = (gchar **) g_ptr_array_free (p, FALSE);

  return nodes;
}

static GDBusInterfaceInfo **
subtree_introspect (GDBusConnection       *connection,
                    const gchar           *sender,
                    const gchar           *object_path,
                    const gchar           *node,
                    gpointer               user_data)
{
  GPtrArray *p;

  p = g_ptr_array_new ();
  if (node == NULL)
    {
      g_ptr_array_add (p, g_dbus_interface_info_ref (manager_interface_info));
    }
  else
    {
      g_ptr_array_add (p, g_dbus_interface_info_ref (block_interface_info));
      if (strlen (node) == 4)
        g_ptr_array_add (p,
                         g_dbus_interface_info_ref (partition_interface_info));
    }

  g_ptr_array_add (p, NULL);

  return (GDBusInterfaceInfo **) g_ptr_array_free (p, FALSE);
}

static const GDBusInterfaceVTable *
subtree_dispatch (GDBusConnection             *connection,
                  const gchar                 *sender,
                  const gchar                 *object_path,
                  const gchar                 *interface_name,
                  const gchar                 *node,
                  gpointer                    *out_user_data,
                  gpointer                     user_data)
{
  const GDBusInterfaceVTable *vtable_to_return;
  gpointer user_data_to_return;

  if (g_strcmp0 (interface_name, "org.gtk.GDBus.Example.Manager") == 0)
    {
      user_data_to_return = "The Root";
      vtable_to_return = &manager_vtable;
    }
  else
    {
      if (strlen (node) == 4)
        user_data_to_return = "A partition";
      else
        user_data_to_return = "A block device";

      if (g_strcmp0 (interface_name, "org.gtk.GDBus.Example.Block") == 0)
        vtable_to_return = &block_vtable;
      else if (g_strcmp0 (interface_name, "org.gtk.GDBus.Example.Partition") == 0)
        vtable_to_return = &partition_vtable;
      else
        g_assert_not_reached ();
    }

  *out_user_data = user_data_to_return;

  return vtable_to_return;
}

const GDBusSubtreeVTable subtree_vtable =
{
  subtree_enumerate,
  subtree_introspect,
  subtree_dispatch
};

/* ---------------------------------------------------------------------------------------------------- */

static void
on_bus_acquired (GDBusConnection *connection,
                 const gchar     *name,
                 gpointer         user_data)
{
  guint registration_id;

  registration_id = g_dbus_connection_register_subtree (connection,
                                                        "/org/gtk/GDBus/TestSubtree/Devices",
                                                        &subtree_vtable,
                                                        G_DBUS_SUBTREE_FLAGS_NONE,
                                                        NULL,  /* user_data */
                                                        NULL,  /* user_data_free_func */
                                                        NULL); /* GError** */
  g_assert (registration_id > 0);
}

static void
on_name_acquired (GDBusConnection *connection,
                  const gchar     *name,
                  gpointer         user_data)
{
}

static void
on_name_lost (GDBusConnection *connection,
              const gchar     *name,
              gpointer         user_data)
{
  exit (1);
}

int
main (int argc, char *argv[])
{
  guint owner_id;
  GMainLoop *loop;

  g_type_init ();

  /* We are lazy here - we don't want to manually provide
   * the introspection data structures - so we just build
   * them from XML.
   */
  introspection_data = g_dbus_node_info_new_for_xml (introspection_xml, NULL);
  g_assert (introspection_data != NULL);

  manager_interface_info = g_dbus_node_info_lookup_interface (introspection_data, "org.gtk.GDBus.Example.Manager");
  block_interface_info = g_dbus_node_info_lookup_interface (introspection_data, "org.gtk.GDBus.Example.Block");
  partition_interface_info = g_dbus_node_info_lookup_interface (introspection_data, "org.gtk.GDBus.Example.Partition");
  g_assert (manager_interface_info != NULL);
  g_assert (block_interface_info != NULL);
  g_assert (partition_interface_info != NULL);

  owner_id = g_bus_own_name (G_BUS_TYPE_SESSION,
                             "org.gtk.GDBus.TestSubtree",
                             G_BUS_NAME_OWNER_FLAGS_NONE,
                             on_bus_acquired,
                             on_name_acquired,
                             on_name_lost,
                             NULL,
                             NULL);

  loop = g_main_loop_new (NULL, FALSE);
  g_main_loop_run (loop);

  g_bus_unown_name (owner_id);

  g_dbus_node_info_unref (introspection_data);

  return 0;
}


Example 4. D-Bus UNIX File Descriptor example

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#include <string.h>
#include <stdlib.h>

#include <sys/types.h>
#include <unistd.h>

#include <time.h>

#include <gio/gio.h>
#include <gio/gunixfdlist.h>

/* see gdbus-example-server.c for the server implementation */
static gint
get_server_stdout (GDBusConnection  *connection,
                   const gchar      *name_owner,
                   GError          **error)
{
  GDBusMessage *method_call_message;
  GDBusMessage *method_reply_message;
  GUnixFDList *fd_list;
  gint fd;

  fd = -1;
  method_call_message = NULL;
  method_reply_message = NULL;

  method_call_message = g_dbus_message_new_method_call (name_owner,
                                                        "/org/gtk/GDBus/TestObject",
                                                        "org.gtk.GDBus.TestInterface",
                                                        "GimmeStdout");
  method_reply_message = g_dbus_connection_send_message_with_reply_sync (connection,
                                                                         method_call_message,
                                                                         G_DBUS_SEND_MESSAGE_FLAGS_NONE,
                                                                         -1,
                                                                         NULL, /* out_serial */
                                                                         NULL, /* cancellable */
                                                                         error);
  if (method_reply_message == NULL)
      goto out;

  if (g_dbus_message_get_message_type (method_reply_message) == G_DBUS_MESSAGE_TYPE_ERROR)
    {
      g_dbus_message_to_gerror (method_reply_message, error);
      goto out;
    }

  fd_list = g_dbus_message_get_unix_fd_list (method_reply_message);
  fd = g_unix_fd_list_get (fd_list, 0, error);

 out:
  g_object_unref (method_call_message);
  g_object_unref (method_reply_message);

  return fd;
}

static void
on_name_appeared (GDBusConnection *connection,
                  const gchar     *name,
                  const gchar     *name_owner,
                  gpointer         user_data)
{
  gint fd;
  GError *error;

  error = NULL;
  fd = get_server_stdout (connection, name_owner, &error);
  if (fd == -1)
    {
      g_printerr ("Error invoking GimmeStdout(): %s\n",
                  error->message);
      g_error_free (error);
      exit (1);
    }
  else
    {
      gchar now_buf[256];
      time_t now;
      gssize len;
      gchar *str;

      now = time (NULL);
      strftime (now_buf,
                sizeof now_buf,
                "%c",
                localtime (&now));

      str = g_strdup_printf ("On %s, gdbus-example-unix-fd-client with pid %d was here!\n",
                             now_buf,
                             (gint) getpid ());
      len = strlen (str);
      g_warn_if_fail (write (fd, str, len) == len);
      close (fd);

      g_print ("Wrote the following on server's stdout:\n%s", str);

      g_free (str);
      exit (0);
    }
}

static void
on_name_vanished (GDBusConnection *connection,
                  const gchar     *name,
                  gpointer         user_data)
{
  g_printerr ("Failed to get name owner for %s\n"
              "Is ./gdbus-example-server running?\n",
              name);
  exit (1);
}

int
main (int argc, char *argv[])
{
  guint watcher_id;
  GMainLoop *loop;

  g_type_init ();

  watcher_id = g_bus_watch_name (G_BUS_TYPE_SESSION,
                                 "org.gtk.GDBus.TestServer",
                                 G_BUS_NAME_WATCHER_FLAGS_NONE,
                                 on_name_appeared,
                                 on_name_vanished,
                                 NULL,
                                 NULL);

  loop = g_main_loop_new (NULL, FALSE);
  g_main_loop_run (loop);

  g_bus_unwatch_name (watcher_id);
  return 0;
}


Example 5. Exporting a GObject

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#include <gio/gio.h>
#include <stdlib.h>

/* ---------------------------------------------------------------------------------------------------- */

/* The object we want to export */
typedef struct _MyObjectClass MyObjectClass;
typedef struct _MyObject MyObject;

struct _MyObjectClass
{
  GObjectClass parent_class;
};

struct _MyObject
{
  GObject parent_instance;

  gint count;
  gchar *name;
};

enum
{
  PROP_0,
  PROP_COUNT,
  PROP_NAME
};

static GType my_object_get_type (void);
G_DEFINE_TYPE (MyObject, my_object, G_TYPE_OBJECT);

static void
my_object_finalize (GObject *object)
{
  MyObject *myobj = (MyObject*)object;

  g_free (myobj->name);

  G_OBJECT_CLASS (my_object_parent_class)->finalize (object);
}

static void
my_object_init (MyObject *object)
{
  object->count = 0;
  object->name = NULL;
}

static void
my_object_get_property (GObject    *object,
                        guint       prop_id,
                        GValue     *value,
                        GParamSpec *pspec)
{
  MyObject *myobj = (MyObject*)object;

  switch (prop_id)
    {
    case PROP_COUNT:
      g_value_set_int (value, myobj->count);
      break;

    case PROP_NAME:
      g_value_set_string (value, myobj->name);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
my_object_set_property (GObject      *object,
                        guint         prop_id,
                        const GValue *value,
                        GParamSpec   *pspec)
{
  MyObject *myobj = (MyObject*)object;

  switch (prop_id)
    {
    case PROP_COUNT:
      myobj->count = g_value_get_int (value);
      break;

    case PROP_NAME:
      g_free (myobj->name);
      myobj->name = g_value_dup_string (value);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
    }
}

static void
my_object_class_init (MyObjectClass *class)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (class);

  gobject_class->finalize = my_object_finalize;
  gobject_class->set_property = my_object_set_property;
  gobject_class->get_property = my_object_get_property;

  g_object_class_install_property (gobject_class,
                                   PROP_COUNT,
                                   g_param_spec_int ("count",
                                                     "Count",
                                                     "Count",
                                                     0, 99999, 0,
                                                     G_PARAM_READWRITE));

  g_object_class_install_property (gobject_class,
                                   PROP_NAME,
                                   g_param_spec_string ("name",
                                                        "Name",
                                                        "Name",
                                                        NULL,
                                                        G_PARAM_READWRITE));
}

/* A method that we want to export */
static void
my_object_change_count (MyObject *myobj,
                        gint      change)
{
  myobj->count = 2 * myobj->count + change;

  g_object_notify (G_OBJECT (myobj), "count");
}

/* ---------------------------------------------------------------------------------------------------- */

static GDBusNodeInfo *introspection_data = NULL;

/* Introspection data for the service we are exporting */
static const gchar introspection_xml[] =
  "<node>"
  "  <interface name='org.myorg.MyObject'>"
  "    <method name='ChangeCount'>"
  "      <arg type='i' name='change' direction='in'/>"
  "    </method>"
  "    <property type='i' name='Count' access='read'/>"
  "    <property type='s' name='Name' access='readwrite'/>"
  "  </interface>"
  "</node>";


static void
handle_method_call (GDBusConnection       *connection,
                    const gchar           *sender,
                    const gchar           *object_path,
                    const gchar           *interface_name,
                    const gchar           *method_name,
                    GVariant              *parameters,
                    GDBusMethodInvocation *invocation,
                    gpointer               user_data)
{
  MyObject *myobj = user_data;

  if (g_strcmp0 (method_name, "ChangeCount") == 0)
    {
      gint change;
      g_variant_get (parameters, "(i)", &change);

      my_object_change_count (myobj, change);

      g_dbus_method_invocation_return_value (invocation, NULL);
    }
}

static GVariant *
handle_get_property (GDBusConnection  *connection,
                     const gchar      *sender,
                     const gchar      *object_path,
                     const gchar      *interface_name,
                     const gchar      *property_name,
                     GError          **error,
                     gpointer          user_data)
{
  GVariant *ret;
  MyObject *myobj = user_data;

  ret = NULL;
  if (g_strcmp0 (property_name, "Count") == 0)
    {
      ret = g_variant_new_int32 (myobj->count);
    }
  else if (g_strcmp0 (property_name, "Name") == 0)
    {
      ret = g_variant_new_string (myobj->name ? myobj->name : "");
    }

  return ret;
}

static gboolean
handle_set_property (GDBusConnection  *connection,
                     const gchar      *sender,
                     const gchar      *object_path,
                     const gchar      *interface_name,
                     const gchar      *property_name,
                     GVariant         *value,
                     GError          **error,
                     gpointer          user_data)
{
  MyObject *myobj = user_data;

  if (g_strcmp0 (property_name, "Count") == 0)
    {
      g_object_set (myobj, "count", g_variant_get_int32 (value), NULL);
    }
  else if (g_strcmp0 (property_name, "Name") == 0)
    {
      g_object_set (myobj, "name", g_variant_get_string (value, NULL), NULL);
    }

  return TRUE;
}


/* for now */
static const GDBusInterfaceVTable interface_vtable =
{
  handle_method_call,
  handle_get_property,
  handle_set_property
};

static void
send_property_change (GObject         *obj,
                      GParamSpec      *pspec,
                      GDBusConnection *connection)
{
  GVariantBuilder *builder;
  GVariantBuilder *invalidated_builder;
  MyObject *myobj = (MyObject *)obj;

  builder = g_variant_builder_new (G_VARIANT_TYPE_ARRAY);
  invalidated_builder = g_variant_builder_new (G_VARIANT_TYPE ("as"));

  if (g_strcmp0 (pspec->name, "count") == 0)
    g_variant_builder_add (builder,
                           "{sv}",
                           "Count", g_variant_new_int32 (myobj->count));
  else if (g_strcmp0 (pspec->name, "name") == 0)
    g_variant_builder_add (builder,
                           "{sv}",
                           "Name", g_variant_new_string (myobj->name ? myobj->name : ""));

  g_dbus_connection_emit_signal (connection,
                                 NULL,
                                 "/org/myorg/MyObject",
                                 "org.freedesktop.DBus.Properties",
                                 "PropertiesChanged",
                                 g_variant_new ("(sa{sv}as)",
                                                "org.myorg.MyObject",
                                                builder,
                                                invalidated_builder),
                                 NULL);
}

static void
on_bus_acquired (GDBusConnection *connection,
                 const gchar     *name,
                 gpointer         user_data)
{
  MyObject *myobj = user_data;
  guint registration_id;

  g_signal_connect (myobj, "notify",
                    G_CALLBACK (send_property_change), connection);
  registration_id = g_dbus_connection_register_object (connection,
                                                       "/org/myorg/MyObject",
                                                       introspection_data->interfaces[0],
                                                       &interface_vtable,
                                                       myobj,
                                                       NULL,  /* user_data_free_func */
                                                       NULL); /* GError** */
  g_assert (registration_id > 0);
}

static void
on_name_acquired (GDBusConnection *connection,
                  const gchar     *name,
                  gpointer         user_data)
{
}

static void
on_name_lost (GDBusConnection *connection,
              const gchar     *name,
              gpointer         user_data)
{
  exit (1);
}

int
main (int argc, char *argv[])
{
  guint owner_id;
  GMainLoop *loop;
  MyObject *myobj;

  g_type_init ();

  /* We are lazy here - we don't want to manually provide
   * the introspection data structures - so we just build
   * them from XML.
   */
  introspection_data = g_dbus_node_info_new_for_xml (introspection_xml, NULL);
  g_assert (introspection_data != NULL);

  myobj = g_object_new (my_object_get_type (), NULL);

  owner_id = g_bus_own_name (G_BUS_TYPE_SESSION,
                             "org.myorg.MyObject",
                             G_BUS_NAME_OWNER_FLAGS_NONE,
                             on_bus_acquired,
                             on_name_acquired,
                             on_name_lost,
                             myobj,
                             NULL);

  loop = g_main_loop_new (NULL, FALSE);
  g_main_loop_run (loop);

  g_bus_unown_name (owner_id);

  g_dbus_node_info_unref (introspection_data);

  g_object_unref (myobj);

  return 0;
}


Details

enum GBusType

typedef enum {
  G_BUS_TYPE_STARTER = -1,
  G_BUS_TYPE_NONE = 0,
  G_BUS_TYPE_SYSTEM  = 1,
  G_BUS_TYPE_SESSION = 2
} GBusType;

An enumeration for well-known message buses.

G_BUS_TYPE_STARTER

An alias for the message bus that activated the process, if any.

G_BUS_TYPE_NONE

Not a message bus.

G_BUS_TYPE_SYSTEM

The system-wide message bus.

G_BUS_TYPE_SESSION

The login session message bus.

Since 2.26


g_bus_get ()

void                g_bus_get                           (GBusType bus_type,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Asynchronously connects to the message bus specified by bus_type.

When the operation is finished, callback will be invoked. You can then call g_bus_get_finish() to get the result of the operation.

This is a asynchronous failable function. See g_bus_get_sync() for the synchronous version.

bus_type :

A GBusType.

cancellable :

A GCancellable or NULL. [allow-none]

callback :

A GAsyncReadyCallback to call when the request is satisfied.

user_data :

The data to pass to callback.

Since 2.26


g_bus_get_finish ()

GDBusConnection *   g_bus_get_finish                    (GAsyncResult *res,
                                                         GError **error);

Finishes an operation started with g_bus_get().

The returned object is a singleton, that is, shared with other callers of g_bus_get() and g_bus_get_sync() for bus_type. In the event that you need a private message bus connection, use g_dbus_address_get_for_bus_sync() and g_dbus_connection_new_for_address().

Note that the returned GDBusConnection object will (usually) have the "exit-on-close" property set to TRUE.

res :

A GAsyncResult obtained from the GAsyncReadyCallback passed to g_bus_get().

error :

Return location for error or NULL.

Returns :

A GDBusConnection or NULL if error is set. Free with g_object_unref(). [transfer full]

Since 2.26


g_bus_get_sync ()

GDBusConnection *   g_bus_get_sync                      (GBusType bus_type,
                                                         GCancellable *cancellable,
                                                         GError **error);

Synchronously connects to the message bus specified by bus_type. Note that the returned object may shared with other callers, e.g. if two separate parts of a process calls this function with the same bus_type, they will share the same object.

This is a synchronous failable function. See g_bus_get() and g_bus_get_finish() for the asynchronous version.

The returned object is a singleton, that is, shared with other callers of g_bus_get() and g_bus_get_sync() for bus_type. In the event that you need a private message bus connection, use g_dbus_address_get_for_bus_sync() and g_dbus_connection_new_for_address().

Note that the returned GDBusConnection object will (usually) have the "exit-on-close" property set to TRUE.

bus_type :

A GBusType.

cancellable :

A GCancellable or NULL. [allow-none]

error :

Return location for error or NULL.

Returns :

A GDBusConnection or NULL if error is set. Free with g_object_unref(). [transfer full]

Since 2.26


GDBusConnection

typedef struct _GDBusConnection GDBusConnection;

The GDBusConnection structure contains only private data and should only be accessed using the provided API.

Since 2.26


enum GDBusConnectionFlags

typedef enum {
  G_DBUS_CONNECTION_FLAGS_NONE = 0,
  G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT = (1<<0),
  G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_SERVER = (1<<1),
  G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_ALLOW_ANONYMOUS = (1<<2),
  G_DBUS_CONNECTION_FLAGS_MESSAGE_BUS_CONNECTION = (1<<3),
  G_DBUS_CONNECTION_FLAGS_DELAY_MESSAGE_PROCESSING = (1<<4)
} GDBusConnectionFlags;

Flags used when creating a new GDBusConnection.

G_DBUS_CONNECTION_FLAGS_NONE

No flags set.

G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT

Perform authentication against server.

G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_SERVER

Perform authentication against client.

G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_ALLOW_ANONYMOUS

When authenticating as a server, allow the anonymous authentication method.

G_DBUS_CONNECTION_FLAGS_MESSAGE_BUS_CONNECTION

Pass this flag if connecting to a peer that is a message bus. This means that the Hello() method will be invoked as part of the connection setup.

G_DBUS_CONNECTION_FLAGS_DELAY_MESSAGE_PROCESSING

If set, processing of D-Bus messages is delayed until g_dbus_connection_start_message_processing() is called.

Since 2.26


g_dbus_connection_new ()

void                g_dbus_connection_new               (GIOStream *stream,
                                                         const gchar *guid,
                                                         GDBusConnectionFlags flags,
                                                         GDBusAuthObserver *observer,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Asynchronously sets up a D-Bus connection for exchanging D-Bus messages with the end represented by stream.

If stream is a GSocketConnection, then the corresponding GSocket will be put into non-blocking mode.

The D-Bus connection will interact with stream from a worker thread. As a result, the caller should not interact with stream after this method has been called, except by calling g_object_unref() on it.

If observer is not NULL it may be used to control the authentication process.

When the operation is finished, callback will be invoked. You can then call g_dbus_connection_new_finish() to get the result of the operation.

This is a asynchronous failable constructor. See g_dbus_connection_new_sync() for the synchronous version.

stream :

A GIOStream.

guid :

The GUID to use if a authenticating as a server or NULL. [allow-none]

flags :

Flags describing how to make the connection.

observer :

A GDBusAuthObserver or NULL. [allow-none]

cancellable :

A GCancellable or NULL. [allow-none]

callback :

A GAsyncReadyCallback to call when the request is satisfied.

user_data :

The data to pass to callback.

Since 2.26


g_dbus_connection_new_finish ()

GDBusConnection *   g_dbus_connection_new_finish        (GAsyncResult *res,
                                                         GError **error);

Finishes an operation started with g_dbus_connection_new().

res :

A GAsyncResult obtained from the GAsyncReadyCallback passed to g_dbus_connection_new().

error :

Return location for error or NULL.

Returns :

A GDBusConnection or NULL if error is set. Free with g_object_unref().

Since 2.26


g_dbus_connection_new_sync ()

GDBusConnection *   g_dbus_connection_new_sync          (GIOStream *stream,
                                                         const gchar *guid,
                                                         GDBusConnectionFlags flags,
                                                         GDBusAuthObserver *observer,
                                                         GCancellable *cancellable,
                                                         GError **error);

Synchronously sets up a D-Bus connection for exchanging D-Bus messages with the end represented by stream.

If stream is a GSocketConnection, then the corresponding GSocket will be put into non-blocking mode.

The D-Bus connection will interact with stream from a worker thread. As a result, the caller should not interact with stream after this method has been called, except by calling g_object_unref() on it.

If observer is not NULL it may be used to control the authentication process.

This is a synchronous failable constructor. See g_dbus_connection_new() for the asynchronous version.

stream :

A GIOStream.

guid :

The GUID to use if a authenticating as a server or NULL. [allow-none]

flags :

Flags describing how to make the connection.

observer :

A GDBusAuthObserver or NULL. [allow-none]

cancellable :

A GCancellable or NULL. [allow-none]

error :

Return location for error or NULL.

Returns :

A GDBusConnection or NULL if error is set. Free with g_object_unref().

Since 2.26


g_dbus_connection_new_for_address ()

void                g_dbus_connection_new_for_address   (const gchar *address,
                                                         GDBusConnectionFlags flags,
                                                         GDBusAuthObserver *observer,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Asynchronously connects and sets up a D-Bus client connection for exchanging D-Bus messages with an endpoint specified by address which must be in the D-Bus address format.

This constructor can only be used to initiate client-side connections - use g_dbus_connection_new() if you need to act as the server. In particular, flags cannot contain the G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_SERVER or G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_ALLOW_ANONYMOUS flags.

When the operation is finished, callback will be invoked. You can then call g_dbus_connection_new_finish() to get the result of the operation.

If observer is not NULL it may be used to control the authentication process.

This is a asynchronous failable constructor. See g_dbus_connection_new_for_address_sync() for the synchronous version.

address :

A D-Bus address.

flags :

Flags describing how to make the connection.

observer :

A GDBusAuthObserver or NULL. [allow-none]

cancellable :

A GCancellable or NULL. [allow-none]

callback :

A GAsyncReadyCallback to call when the request is satisfied.

user_data :

The data to pass to callback.

Since 2.26


g_dbus_connection_new_for_address_finish ()

GDBusConnection *   g_dbus_connection_new_for_address_finish
                                                        (GAsyncResult *res,
                                                         GError **error);

Finishes an operation started with g_dbus_connection_new_for_address().

res :

A GAsyncResult obtained from the GAsyncReadyCallback passed to g_dbus_connection_new().

error :

Return location for error or NULL.

Returns :

A GDBusConnection or NULL if error is set. Free with g_object_unref().

Since 2.26


g_dbus_connection_new_for_address_sync ()

GDBusConnection *   g_dbus_connection_new_for_address_sync
                                                        (const gchar *address,
                                                         GDBusConnectionFlags flags,
                                                         GDBusAuthObserver *observer,
                                                         GCancellable *cancellable,
                                                         GError **error);

Synchronously connects and sets up a D-Bus client connection for exchanging D-Bus messages with an endpoint specified by address which must be in the D-Bus address format.

This constructor can only be used to initiate client-side connections - use g_dbus_connection_new_sync() if you need to act as the server. In particular, flags cannot contain the G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_SERVER or G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_ALLOW_ANONYMOUS flags.

This is a synchronous failable constructor. See g_dbus_connection_new_for_address() for the asynchronous version.

If observer is not NULL it may be used to control the authentication process.

address :

A D-Bus address.

flags :

Flags describing how to make the connection.

observer :

A GDBusAuthObserver or NULL. [allow-none]

cancellable :

A GCancellable or NULL. [allow-none]

error :

Return location for error or NULL.

Returns :

A GDBusConnection or NULL if error is set. Free with g_object_unref().

Since 2.26


g_dbus_connection_start_message_processing ()

void                g_dbus_connection_start_message_processing
                                                        (GDBusConnection *connection);

If connection was created with G_DBUS_CONNECTION_FLAGS_DELAY_MESSAGE_PROCESSING, this method starts processing messages. Does nothing on if connection wasn't created with this flag or if the method has already been called.

connection :

A GDBusConnection.

Since 2.26


g_dbus_connection_close ()

void                g_dbus_connection_close             (GDBusConnection *connection,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Closes connection. Note that this never causes the process to exit (this might only happen if the other end of a shared message bus connection disconnects, see "exit-on-close").

Once the connection is closed, operations such as sending a message will return with the error G_IO_ERROR_CLOSED. Closing a connection will not automatically flush the connection so queued messages may be lost. Use g_dbus_connection_flush() if you need such guarantees.

If connection is already closed, this method fails with G_IO_ERROR_CLOSED.

When connection has been closed, the "closed" signal is emitted in the thread-default main loop of the thread that connection was constructed in.

This is an asynchronous method. When the operation is finished, callback will be invoked in the thread-default main loop of the thread you are calling this method from. You can then call g_dbus_connection_close_finish() to get the result of the operation. See g_dbus_connection_close_sync() for the synchronous version.

connection :

A GDBusConnection.

cancellable :

A GCancellable or NULL. [allow-none]

callback :

A GAsyncReadyCallback to call when the request is satisfied or NULL if you don't care about the result. [allow-none]

user_data :

The data to pass to callback.

Since 2.26


g_dbus_connection_close_finish ()

gboolean            g_dbus_connection_close_finish      (GDBusConnection *connection,
                                                         GAsyncResult *res,
                                                         GError **error);

Finishes an operation started with g_dbus_connection_close().

connection :

A GDBusConnection.

res :

A GAsyncResult obtained from the GAsyncReadyCallback passed to g_dbus_connection_close().

error :

Return location for error or NULL.

Returns :

TRUE if the operation succeeded, FALSE if error is set.

Since 2.26


g_dbus_connection_close_sync ()

gboolean            g_dbus_connection_close_sync        (GDBusConnection *connection,
                                                         GCancellable *cancellable,
                                                         GError **error);

Synchronously closees connection. The calling thread is blocked until this is done. See g_dbus_connection_close() for the asynchronous version of this method and more details about what it does.

connection :

A GDBusConnection.

cancellable :

A GCancellable or NULL. [allow-none]

error :

Return location for error or NULL.

Returns :

TRUE if the operation succeeded, FALSE if error is set.

Since 2.26


g_dbus_connection_is_closed ()

gboolean            g_dbus_connection_is_closed         (GDBusConnection *connection);

Gets whether connection is closed.

connection :

A GDBusConnection.

Returns :

TRUE if the connection is closed, FALSE otherwise.

Since 2.26


g_dbus_connection_flush ()

void                g_dbus_connection_flush             (GDBusConnection *connection,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Asynchronously flushes connection, that is, writes all queued outgoing message to the transport and then flushes the transport (using g_output_stream_flush_async()). This is useful in programs that wants to emit a D-Bus signal and then exit immediately. Without flushing the connection, there is no guarantee that the message has been sent to the networking buffers in the OS kernel.

This is an asynchronous method. When the operation is finished, callback will be invoked in the thread-default main loop of the thread you are calling this method from. You can then call g_dbus_connection_flush_finish() to get the result of the operation. See g_dbus_connection_flush_sync() for the synchronous version.

connection :

A GDBusConnection.

cancellable :

A GCancellable or NULL. [allow-none]

callback :

A GAsyncReadyCallback to call when the request is satisfied or NULL if you don't care about the result. [allow-none]

user_data :

The data to pass to callback.

Since 2.26


g_dbus_connection_flush_finish ()

gboolean            g_dbus_connection_flush_finish      (GDBusConnection *connection,
                                                         GAsyncResult *res,
                                                         GError **error);

Finishes an operation started with g_dbus_connection_flush().

connection :

A GDBusConnection.

res :

A GAsyncResult obtained from the GAsyncReadyCallback passed to g_dbus_connection_flush().

error :

Return location for error or NULL.

Returns :

TRUE if the operation succeeded, FALSE if error is set.

Since 2.26


g_dbus_connection_flush_sync ()

gboolean            g_dbus_connection_flush_sync        (GDBusConnection *connection,
                                                         GCancellable *cancellable,
                                                         GError **error);

Synchronously flushes connection. The calling thread is blocked until this is done. See g_dbus_connection_flush() for the asynchronous version of this method and more details about what it does.

connection :

A GDBusConnection.

cancellable :

A GCancellable or NULL. [allow-none]

error :

Return location for error or NULL.

Returns :

TRUE if the operation succeeded, FALSE if error is set.

Since 2.26


g_dbus_connection_get_exit_on_close ()

gboolean            g_dbus_connection_get_exit_on_close (GDBusConnection *connection);

Gets whether the process is terminated when connection is closed by the remote peer. See "exit-on-close" for more details.

connection :

A GDBusConnection.

Returns :

Whether the process is terminated when connection is closed by the remote peer.

Since 2.26


g_dbus_connection_set_exit_on_close ()

void                g_dbus_connection_set_exit_on_close (GDBusConnection *connection,
                                                         gboolean exit_on_close);

Sets whether the process should be terminated when connection is closed by the remote peer. See "exit-on-close" for more details.

Note that this function should be used with care. Most modern UNIX desktops tie the notion of a user session the session bus, and expect all of a users applications to quit when their bus connection goes away. If you are setting exit_on_close to FALSE for the shared session bus connection, you should make sure that your application exits when the user session ends.

connection :

A GDBusConnection.

exit_on_close :

Whether the process should be terminated when connection is closed by the remote peer.

Since 2.26


g_dbus_connection_get_stream ()

GIOStream *         g_dbus_connection_get_stream        (GDBusConnection *connection);

Gets the underlying stream used for IO.

While the GDBusConnection is active, it will interact with this stream from a worker thread, so it is not safe to interact with the stream directly.

connection :

a GDBusConnection

Returns :

the stream used for IO. [transfer none]

Since 2.26


g_dbus_connection_get_guid ()

const gchar *       g_dbus_connection_get_guid          (GDBusConnection *connection);

The GUID of the peer performing the role of server when authenticating. See "guid" for more details.

connection :

A GDBusConnection.

Returns :

The GUID. Do not free this string, it is owned by connection.

Since 2.26


g_dbus_connection_get_unique_name ()

const gchar *       g_dbus_connection_get_unique_name   (GDBusConnection *connection);

Gets the unique name of connection as assigned by the message bus. This can also be used to figure out if connection is a message bus connection.

connection :

A GDBusConnection.

Returns :

The unique name or NULL if connection is not a message bus connection. Do not free this string, it is owned by connection.

Since 2.26


enum GDBusCapabilityFlags

typedef enum {
  G_DBUS_CAPABILITY_FLAGS_NONE = 0,
  G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING = (1<<0)
} GDBusCapabilityFlags;

Capabilities negotiated with the remote peer.

G_DBUS_CAPABILITY_FLAGS_NONE

No flags set.

G_DBUS_CAPABILITY_FLAGS_UNIX_FD_PASSING

The connection supports exchanging UNIX file descriptors with the remote peer.

Since 2.26


g_dbus_connection_get_capabilities ()

GDBusCapabilityFlags g_dbus_connection_get_capabilities (GDBusConnection *connection);

Gets the capabilities negotiated with the remote peer

connection :

A GDBusConnection.

Returns :

Zero or more flags from the GDBusCapabilityFlags enumeration.

Since 2.26


g_dbus_connection_get_peer_credentials ()

GCredentials *      g_dbus_connection_get_peer_credentials
                                                        (GDBusConnection *connection);

Gets the credentials of the authenticated peer. This will always return NULL unless connection acted as a server (e.g. G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_SERVER was passed) when set up and the client passed credentials as part of the authentication process.

In a message bus setup, the message bus is always the server and each application is a client. So this method will always return NULL for message bus clients.

connection :

A GDBusConnection.

Returns :

A GCredentials or NULL if not available. Do not free this object, it is owned by connection. [transfer none]

Since 2.26


enum GDBusCallFlags

typedef enum {
  G_DBUS_CALL_FLAGS_NONE = 0,
  G_DBUS_CALL_FLAGS_NO_AUTO_START = (1<<0)
} GDBusCallFlags;

Flags used in g_dbus_connection_call() and similar APIs.

G_DBUS_CALL_FLAGS_NONE

No flags set.

G_DBUS_CALL_FLAGS_NO_AUTO_START

The bus must not launch an owner for the destination name in response to this method invocation.

Since 2.26


g_dbus_connection_call ()

void                g_dbus_connection_call              (GDBusConnection *connection,
                                                         const gchar *bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         const GVariantType *reply_type,
                                                         GDBusCallFlags flags,
                                                         gint timeout_msec,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Asynchronously invokes the method_name method on the interface_name D-Bus interface on the remote object at object_path owned by bus_name.

If connection is closed then the operation will fail with G_IO_ERROR_CLOSED. If cancellable is canceled, the operation will fail with G_IO_ERROR_CANCELLED. If parameters contains a value not compatible with the D-Bus protocol, the operation fails with G_IO_ERROR_INVALID_ARGUMENT.

If reply_type is non-NULL then the reply will be checked for having this type and an error will be raised if it does not match. Said another way, if you give a reply_type then any non-NULL return value will be of this type.

If the parameters GVariant is floating, it is consumed. This allows convenient 'inline' use of g_variant_new(), e.g.:

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g_dbus_connection_call (connection,
                        "org.freedesktop.StringThings",
                        "/org/freedesktop/StringThings",
                        "org.freedesktop.StringThings",
                        "TwoStrings",
                        g_variant_new ("(ss)",
                                       "Thing One",
                                       "Thing Two"),
                        NULL,
                        G_DBUS_CALL_FLAGS_NONE,
                        -1,
                        NULL,
                        (GAsyncReadyCallback) two_strings_done,
                        NULL);

This is an asynchronous method. When the operation is finished, callback will be invoked in the thread-default main loop of the thread you are calling this method from. You can then call g_dbus_connection_call_finish() to get the result of the operation. See g_dbus_connection_call_sync() for the synchronous version of this function.

If callback is NULL then the D-Bus method call message will be sent with the G_DBUS_MESSAGE_FLAGS_NO_REPLY_EXPECTED flag set.

connection :

A GDBusConnection.

bus_name :

A unique or well-known bus name or NULL if connection is not a message bus connection. [allow-none]

object_path :

Path of remote object.

interface_name :

D-Bus interface to invoke method on.

method_name :

The name of the method to invoke.

parameters :

A GVariant tuple with parameters for the method or NULL if not passing parameters. [allow-none]

reply_type :

The expected type of the reply, or NULL. [allow-none]

flags :

Flags from the GDBusCallFlags enumeration.

timeout_msec :

The timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout.

cancellable :

A GCancellable or NULL. [allow-none]

callback :

A GAsyncReadyCallback to call when the request is satisfied or NULL if you don't care about the result of the method invocation. [allow-none]

user_data :

The data to pass to callback.

Since 2.26


g_dbus_connection_call_finish ()

GVariant *          g_dbus_connection_call_finish       (GDBusConnection *connection,
                                                         GAsyncResult *res,
                                                         GError **error);

Finishes an operation started with g_dbus_connection_call().

connection :

A GDBusConnection.

res :

A GAsyncResult obtained from the GAsyncReadyCallback passed to g_dbus_connection_call().

error :

Return location for error or NULL.

Returns :

NULL if error is set. Otherwise a GVariant tuple with return values. Free with g_variant_unref().

Since 2.26


g_dbus_connection_call_sync ()

GVariant *          g_dbus_connection_call_sync         (GDBusConnection *connection,
                                                         const gchar *bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         const GVariantType *reply_type,
                                                         GDBusCallFlags flags,
                                                         gint timeout_msec,
                                                         GCancellable *cancellable,
                                                         GError **error);

Synchronously invokes the method_name method on the interface_name D-Bus interface on the remote object at object_path owned by bus_name.

If connection is closed then the operation will fail with G_IO_ERROR_CLOSED. If cancellable is canceled, the operation will fail with G_IO_ERROR_CANCELLED. If parameters contains a value not compatible with the D-Bus protocol, the operation fails with G_IO_ERROR_INVALID_ARGUMENT.

If reply_type is non-NULL then the reply will be checked for having this type and an error will be raised if it does not match. Said another way, if you give a reply_type then any non-NULL return value will be of this type.

If the parameters GVariant is floating, it is consumed. This allows convenient 'inline' use of g_variant_new(), e.g.:

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g_dbus_connection_call_sync (connection,
                             "org.freedesktop.StringThings",
                             "/org/freedesktop/StringThings",
                             "org.freedesktop.StringThings",
                             "TwoStrings",
                             g_variant_new ("(ss)",
                                            "Thing One",
                                            "Thing Two"),
                             NULL,
                             G_DBUS_CALL_FLAGS_NONE,
                             -1,
                             NULL,
                             &error);

The calling thread is blocked until a reply is received. See g_dbus_connection_call() for the asynchronous version of this method.

connection :

A GDBusConnection.

bus_name :

A unique or well-known bus name.

object_path :

Path of remote object.

interface_name :

D-Bus interface to invoke method on.

method_name :

The name of the method to invoke.

parameters :

A GVariant tuple with parameters for the method or NULL if not passing parameters. [allow-none]

reply_type :

The expected type of the reply, or NULL. [allow-none]

flags :

Flags from the GDBusCallFlags enumeration.

timeout_msec :

The timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout.

cancellable :

A GCancellable or NULL. [allow-none]

error :

Return location for error or NULL.

Returns :

NULL if error is set. Otherwise a GVariant tuple with return values. Free with g_variant_unref().

Since 2.26


g_dbus_connection_call_with_unix_fd_list ()

void                g_dbus_connection_call_with_unix_fd_list
                                                        (GDBusConnection *connection,
                                                         const gchar *bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         const GVariantType *reply_type,
                                                         GDBusCallFlags flags,
                                                         gint timeout_msec,
                                                         GUnixFDList *fd_list,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Like g_dbus_connection_call() but also takes a GUnixFDList object.

This method is only available on UNIX.

connection :

A GDBusConnection.

bus_name :

A unique or well-known bus name or NULL if connection is not a message bus connection. [allow-none]

object_path :

Path of remote object.

interface_name :

D-Bus interface to invoke method on.

method_name :

The name of the method to invoke.

parameters :

A GVariant tuple with parameters for the method or NULL if not passing parameters. [allow-none]

reply_type :

The expected type of the reply, or NULL. [allow-none]

flags :

Flags from the GDBusCallFlags enumeration.

timeout_msec :

The timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout.

fd_list :

A GUnixFDList or NULL. [allow-none]

cancellable :

A GCancellable or NULL. [allow-none]

callback :

A GAsyncReadyCallback to call when the request is satisfied or NULL if you don't * care about the result of the method invocation. [allow-none]

user_data :

The data to pass to callback.

Since 2.30


g_dbus_connection_call_with_unix_fd_list_finish ()

GVariant *          g_dbus_connection_call_with_unix_fd_list_finish
                                                        (GDBusConnection *connection,
                                                         GUnixFDList **out_fd_list,
                                                         GAsyncResult *res,
                                                         GError **error);

Finishes an operation started with g_dbus_connection_call_with_unix_fd_list().

connection :

A GDBusConnection.

out_fd_list :

Return location for a GUnixFDList or NULL. [out][allow-none]

res :

A GAsyncResult obtained from the GAsyncReadyCallback passed to g_dbus_connection_call_with_unix_fd_list().

error :

Return location for error or NULL.

Returns :

NULL if error is set. Otherwise a GVariant tuple with return values. Free with g_variant_unref().

Since 2.30


g_dbus_connection_call_with_unix_fd_list_sync ()

GVariant *          g_dbus_connection_call_with_unix_fd_list_sync
                                                        (GDBusConnection *connection,
                                                         const gchar *bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         const GVariantType *reply_type,
                                                         GDBusCallFlags flags,
                                                         gint timeout_msec,
                                                         GUnixFDList *fd_list,
                                                         GUnixFDList **out_fd_list,
                                                         GCancellable *cancellable,
                                                         GError **error);

Like g_dbus_connection_call_sync() but also takes and returns GUnixFDList objects.

This method is only available on UNIX.

connection :

A GDBusConnection.

bus_name :

A unique or well-known bus name.

object_path :

Path of remote object.

interface_name :

D-Bus interface to invoke method on.

method_name :

The name of the method to invoke.

parameters :

A GVariant tuple with parameters for the method or NULL if not passing parameters. [allow-none]

reply_type :

The expected type of the reply, or NULL. [allow-none]

flags :

Flags from the GDBusCallFlags enumeration.

timeout_msec :

The timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout.

fd_list :

A GUnixFDList or NULL. [allow-none]

out_fd_list :

Return location for a GUnixFDList or NULL. [out][allow-none]

cancellable :

A GCancellable or NULL. [allow-none]

error :

Return location for error or NULL.

Returns :

NULL if error is set. Otherwise a GVariant tuple with return values. Free with g_variant_unref().

Since 2.30


g_dbus_connection_emit_signal ()

gboolean            g_dbus_connection_emit_signal       (GDBusConnection *connection,
                                                         const gchar *destination_bus_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *signal_name,
                                                         GVariant *parameters,
                                                         GError **error);

Emits a signal.

If the parameters GVariant is floating, it is consumed.

This can only fail if parameters is not compatible with the D-Bus protocol.

connection :

A GDBusConnection.

destination_bus_name :

The unique bus name for the destination for the signal or NULL to emit to all listeners. [allow-none]

object_path :

Path of remote object.

interface_name :

D-Bus interface to emit a signal on.

signal_name :

The name of the signal to emit.

parameters :

A GVariant tuple with parameters for the signal or NULL if not passing parameters. [allow-none]

error :

Return location for error or NULL.

Returns :

TRUE unless error is set.

Since 2.26


enum GDBusSignalFlags

typedef enum {
  G_DBUS_SIGNAL_FLAGS_NONE = 0,
  G_DBUS_SIGNAL_FLAGS_NO_MATCH_RULE = (1<<0)
} GDBusSignalFlags;

Flags used when subscribing to signals via g_dbus_connection_signal_subscribe().

G_DBUS_SIGNAL_FLAGS_NONE

No flags set.

G_DBUS_SIGNAL_FLAGS_NO_MATCH_RULE

Don't actually send the AddMatch D-Bus call for this signal subscription. This gives you more control over which match rules you add (but you must add them manually).

Since 2.26


GDBusSignalCallback ()

void                (*GDBusSignalCallback)              (GDBusConnection *connection,
                                                         const gchar *sender_name,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *signal_name,
                                                         GVariant *parameters,
                                                         gpointer user_data);

Signature for callback function used in g_dbus_connection_signal_subscribe().

connection :

A GDBusConnection.

sender_name :

The unique bus name of the sender of the signal.

object_path :

The object path that the signal was emitted on.

interface_name :

The name of the interface.

signal_name :

The name of the signal.

parameters :

A GVariant tuple with parameters for the signal.

user_data :

User data passed when subscribing to the signal.

Since 2.26


g_dbus_connection_signal_subscribe ()

guint               g_dbus_connection_signal_subscribe  (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *interface_name,
                                                         const gchar *member,
                                                         const gchar *object_path,
                                                         const gchar *arg0,
                                                         GDBusSignalFlags flags,
                                                         GDBusSignalCallback callback,
                                                         gpointer user_data,
                                                         GDestroyNotify user_data_free_func);

Subscribes to signals on connection and invokes callback with a whenever the signal is received. Note that callback will be invoked in the thread-default main loop of the thread you are calling this method from.

If connection is not a message bus connection, sender must be NULL.

If sender is a well-known name note that callback is invoked with the unique name for the owner of sender, not the well-known name as one would expect. This is because the message bus rewrites the name. As such, to avoid certain race conditions, users should be tracking the name owner of the well-known name and use that when processing the received signal.

connection :

A GDBusConnection.

sender :

Sender name to match on (unique or well-known name) or NULL to listen from all senders. [allow-none]

interface_name :

D-Bus interface name to match on or NULL to match on all interfaces. [allow-none]

member :

D-Bus signal name to match on or NULL to match on all signals. [allow-none]

object_path :

Object path to match on or NULL to match on all object paths. [allow-none]

arg0 :

Contents of first string argument to match on or NULL to match on all kinds of arguments. [allow-none]

flags :

Flags describing how to subscribe to the signal (currently unused).

callback :

Callback to invoke when there is a signal matching the requested data.

user_data :

User data to pass to callback.

user_data_free_func :

Function to free user_data with when subscription is removed or NULL. [allow-none]

Returns :

A subscription identifier that can be used with g_dbus_connection_signal_unsubscribe().

Since 2.26


g_dbus_connection_signal_unsubscribe ()

void                g_dbus_connection_signal_unsubscribe
                                                        (GDBusConnection *connection,
                                                         guint subscription_id);

Unsubscribes from signals.

connection :

A GDBusConnection.

subscription_id :

A subscription id obtained from g_dbus_connection_signal_subscribe().

Since 2.26


enum GDBusSendMessageFlags

typedef enum {
  G_DBUS_SEND_MESSAGE_FLAGS_NONE = 0,
  G_DBUS_SEND_MESSAGE_FLAGS_PRESERVE_SERIAL = (1<<0)
} GDBusSendMessageFlags;

Flags used when sending GDBusMessages on a GDBusConnection.

G_DBUS_SEND_MESSAGE_FLAGS_NONE

No flags set.

G_DBUS_SEND_MESSAGE_FLAGS_PRESERVE_SERIAL

Do not automatically assign a serial number from the GDBusConnection object when sending a message.

Since 2.26


g_dbus_connection_send_message ()

gboolean            g_dbus_connection_send_message      (GDBusConnection *connection,
                                                         GDBusMessage *message,
                                                         GDBusSendMessageFlags flags,
                                                         volatile guint32 *out_serial,
                                                         GError **error);

Asynchronously sends message to the peer represented by connection.

Unless flags contain the G_DBUS_SEND_MESSAGE_FLAGS_PRESERVE_SERIAL flag, the serial number will be assigned by connection and set on message via g_dbus_message_set_serial(). If out_serial is not NULL, then the serial number used will be written to this location prior to submitting the message to the underlying transport.

If connection is closed then the operation will fail with G_IO_ERROR_CLOSED. If message is not well-formed, the operation fails with G_IO_ERROR_INVALID_ARGUMENT.

See Example 2, “D-Bus server example” and Example 4, “D-Bus UNIX File Descriptor example” for an example of how to use this low-level API to send and receive UNIX file descriptors.

Note that message must be unlocked, unless flags contain the G_DBUS_SEND_MESSAGE_FLAGS_PRESERVE_SERIAL flag.

connection :

A GDBusConnection.

message :

A GDBusMessage

flags :

Flags affecting how the message is sent.

out_serial :

Return location for serial number assigned to message when sending it or NULL. [out][allow-none]

error :

Return location for error or NULL.

Returns :

TRUE if the message was well-formed and queued for transmission, FALSE if error is set.

Since 2.26


g_dbus_connection_send_message_with_reply ()

void                g_dbus_connection_send_message_with_reply
                                                        (GDBusConnection *connection,
                                                         GDBusMessage *message,
                                                         GDBusSendMessageFlags flags,
                                                         gint timeout_msec,
                                                         volatile guint32 *out_serial,
                                                         GCancellable *cancellable,
                                                         GAsyncReadyCallback callback,
                                                         gpointer user_data);

Asynchronously sends message to the peer represented by connection.

Unless flags contain the G_DBUS_SEND_MESSAGE_FLAGS_PRESERVE_SERIAL flag, the serial number will be assigned by connection and set on message via g_dbus_message_set_serial(). If out_serial is not NULL, then the serial number used will be written to this location prior to submitting the message to the underlying transport.

If connection is closed then the operation will fail with G_IO_ERROR_CLOSED. If cancellable is canceled, the operation will fail with G_IO_ERROR_CANCELLED. If message is not well-formed, the operation fails with G_IO_ERROR_INVALID_ARGUMENT.

This is an asynchronous method. When the operation is finished, callback will be invoked in the thread-default main loop of the thread you are calling this method from. You can then call g_dbus_connection_send_message_with_reply_finish() to get the result of the operation. See g_dbus_connection_send_message_with_reply_sync() for the synchronous version.

Note that message must be unlocked, unless flags contain the G_DBUS_SEND_MESSAGE_FLAGS_PRESERVE_SERIAL flag.

See Example 2, “D-Bus server example” and Example 4, “D-Bus UNIX File Descriptor example” for an example of how to use this low-level API to send and receive UNIX file descriptors.

connection :

A GDBusConnection.

message :

A GDBusMessage.

flags :

Flags affecting how the message is sent.

timeout_msec :

The timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout.

out_serial :

Return location for serial number assigned to message when sending it or NULL. [out][allow-none]

cancellable :

A GCancellable or NULL. [allow-none]

callback :

A GAsyncReadyCallback to call when the request is satisfied or NULL if you don't care about the result. [allow-none]

user_data :

The data to pass to callback.

Since 2.26


g_dbus_connection_send_message_with_reply_finish ()

GDBusMessage *      g_dbus_connection_send_message_with_reply_finish
                                                        (GDBusConnection *connection,
                                                         GAsyncResult *res,
                                                         GError **error);

Finishes an operation started with g_dbus_connection_send_message_with_reply().

Note that error is only set if a local in-process error occurred. That is to say that the returned GDBusMessage object may be of type G_DBUS_MESSAGE_TYPE_ERROR. Use g_dbus_message_to_gerror() to transcode this to a GError.

See Example 2, “D-Bus server example” and Example 4, “D-Bus UNIX File Descriptor example” for an example of how to use this low-level API to send and receive UNIX file descriptors.

connection :

a GDBusConnection

res :

A GAsyncResult obtained from the GAsyncReadyCallback passed to g_dbus_connection_send_message_with_reply().

error :

Return location for error or NULL.

Returns :

A locked GDBusMessage or NULL if error is set. [transfer full]

Since 2.26


g_dbus_connection_send_message_with_reply_sync ()

GDBusMessage *      g_dbus_connection_send_message_with_reply_sync
                                                        (GDBusConnection *connection,
                                                         GDBusMessage *message,
                                                         GDBusSendMessageFlags flags,
                                                         gint timeout_msec,
                                                         volatile guint32 *out_serial,
                                                         GCancellable *cancellable,
                                                         GError **error);

Synchronously sends message to the peer represented by connection and blocks the calling thread until a reply is received or the timeout is reached. See g_dbus_connection_send_message_with_reply() for the asynchronous version of this method.

Unless flags contain the G_DBUS_SEND_MESSAGE_FLAGS_PRESERVE_SERIAL flag, the serial number will be assigned by connection and set on message via g_dbus_message_set_serial(). If out_serial is not NULL, then the serial number used will be written to this location prior to submitting the message to the underlying transport.

If connection is closed then the operation will fail with G_IO_ERROR_CLOSED. If cancellable is canceled, the operation will fail with G_IO_ERROR_CANCELLED. If message is not well-formed, the operation fails with G_IO_ERROR_INVALID_ARGUMENT.

Note that error is only set if a local in-process error occurred. That is to say that the returned GDBusMessage object may be of type G_DBUS_MESSAGE_TYPE_ERROR. Use g_dbus_message_to_gerror() to transcode this to a GError.

See Example 2, “D-Bus server example” and Example 4, “D-Bus UNIX File Descriptor example” for an example of how to use this low-level API to send and receive UNIX file descriptors.

Note that message must be unlocked, unless flags contain the G_DBUS_SEND_MESSAGE_FLAGS_PRESERVE_SERIAL flag.

connection :

A GDBusConnection.

message :

A GDBusMessage.

flags :

Flags affecting how the message is sent.

timeout_msec :

The timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout.

out_serial :

Return location for serial number assigned to message when sending it or NULL. [out][allow-none]

cancellable :

A GCancellable or NULL. [allow-none]

error :

Return location for error or NULL.

Returns :

A locked GDBusMessage that is the reply to message or NULL if error is set. [transfer full]

Since 2.26


GDBusMessageFilterFunction ()

GDBusMessage *      (*GDBusMessageFilterFunction)       (GDBusConnection *connection,
                                                         GDBusMessage *message,
                                                         gboolean incoming,
                                                         gpointer user_data);

Signature for function used in g_dbus_connection_add_filter().

A filter function is passed a GDBusMessage and expected to return a GDBusMessage too. Passive filter functions that don't modify the message can simply return the message object:

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static GDBusMessage *
passive_filter (GDBusConnection *connection
                GDBusMessage    *message,
                gboolean         incoming,
                gpointer         user_data)
{
  /* inspect @message */
  return message;
}

Filter functions that wants to drop a message can simply return NULL:

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static GDBusMessage *
drop_filter (GDBusConnection *connection
             GDBusMessage    *message,
             gboolean         incoming,
             gpointer         user_data)
{
  if (should_drop_message)
    {
      g_object_unref (message);
      message = NULL;
    }
  return message;
}

Finally, a filter function may modify a message by copying it:

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static GDBusMessage *
modifying_filter (GDBusConnection *connection
                  GDBusMessage    *message,
                  gboolean         incoming,
                  gpointer         user_data)
{
  GDBusMessage *copy;
  GError *error;

  error = NULL;
  copy = g_dbus_message_copy (message, &error);
  /* handle @error being is set */
  g_object_unref (message);

  /* modify @copy */

  return copy;
}

If the returned GDBusMessage is different from message and cannot be sent on connection (it could use features, such as file descriptors, not compatible with connection), then a warning is logged to standard error. Applications can check this ahead of time using g_dbus_message_to_blob() passing a GDBusCapabilityFlags value obtained from connection.

connection :

A GDBusConnection. [transfer none]

message :

A locked GDBusMessage that the filter function takes ownership of. [transfer full]

incoming :

TRUE if it is a message received from the other peer, FALSE if it is a message to be sent to the other peer.

user_data :

User data passed when adding the filter.

Returns :

A GDBusMessage that will be freed with g_object_unref() or NULL to drop the message. Passive filter functions can simply return the passed message object. [transfer full][allow-none]

Since 2.26


g_dbus_connection_add_filter ()

guint               g_dbus_connection_add_filter        (GDBusConnection *connection,
                                                         GDBusMessageFilterFunction filter_function,
                                                         gpointer user_data,
                                                         GDestroyNotify user_data_free_func);

Adds a message filter. Filters are handlers that are run on all incoming and outgoing messages, prior to standard dispatch. Filters are run in the order that they were added. The same handler can be added as a filter more than once, in which case it will be run more than once. Filters added during a filter callback won't be run on the message being processed. Filter functions are allowed to modify and even drop messages.

Note that filters are run in a dedicated message handling thread so they can't block and, generally, can't do anything but signal a worker thread. Also note that filters are rarely needed - use API such as g_dbus_connection_send_message_with_reply(), g_dbus_connection_signal_subscribe() or g_dbus_connection_call() instead.

If a filter consumes an incoming message the message is not dispatched anywhere else - not even the standard dispatch machinery (that API such as g_dbus_connection_signal_subscribe() and g_dbus_connection_send_message_with_reply() relies on) will see the message. Similary, if a filter consumes an outgoing message, the message will not be sent to the other peer.

connection :

A GDBusConnection.

filter_function :

A filter function.

user_data :

User data to pass to filter_function.

user_data_free_func :

Function to free user_data with when filter is removed or NULL.

Returns :

A filter identifier that can be used with g_dbus_connection_remove_filter().

Since 2.26


g_dbus_connection_remove_filter ()

void                g_dbus_connection_remove_filter     (GDBusConnection *connection,
                                                         guint filter_id);

Removes a filter.

connection :

a GDBusConnection

filter_id :

an identifier obtained from g_dbus_connection_add_filter()

Since 2.26


GDBusInterfaceVTable

typedef struct {
  GDBusInterfaceMethodCallFunc  method_call;
  GDBusInterfaceGetPropertyFunc get_property;
  GDBusInterfaceSetPropertyFunc set_property;
} GDBusInterfaceVTable;

Virtual table for handling properties and method calls for a D-Bus interface.

If you want to handle getting/setting D-Bus properties asynchronously, simply register an object with the org.freedesktop.DBus.Properties D-Bus interface using g_dbus_connection_register_object().

GDBusInterfaceMethodCallFunc method_call;

Function for handling incoming method calls.

GDBusInterfaceGetPropertyFunc get_property;

Function for getting a property.

GDBusInterfaceSetPropertyFunc set_property;

Function for setting a property.

Since 2.26


GDBusInterfaceMethodCallFunc ()

void                (*GDBusInterfaceMethodCallFunc)     (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *method_name,
                                                         GVariant *parameters,
                                                         GDBusMethodInvocation *invocation,
                                                         gpointer user_data);

The type of the method_call function in GDBusInterfaceVTable.

connection :

A GDBusConnection.

sender :

The unique bus name of the remote caller.

object_path :

The object path that the method was invoked on.

interface_name :

The D-Bus interface name the method was invoked on.

method_name :

The name of the method that was invoked.

parameters :

A GVariant tuple with parameters.

invocation :

A GDBusMethodInvocation object that can be used to return a value or error.

user_data :

The user_data gpointer passed to g_dbus_connection_register_object().

Since 2.26


GDBusInterfaceGetPropertyFunc ()

GVariant *          (*GDBusInterfaceGetPropertyFunc)    (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *property_name,
                                                         GError **error,
                                                         gpointer user_data);

The type of the get_property function in GDBusInterfaceVTable.

connection :

A GDBusConnection.

sender :

The unique bus name of the remote caller.

object_path :

The object path that the method was invoked on.

interface_name :

The D-Bus interface name for the property.

property_name :

The name of the property to get the value of.

error :

Return location for error.

user_data :

The user_data gpointer passed to g_dbus_connection_register_object().

Returns :

A GVariant with the value for property_name or NULL if error is set. If the returned GVariant is floating, it is consumed - otherwise its reference count is decreased by one.

Since 2.26


GDBusInterfaceSetPropertyFunc ()

gboolean            (*GDBusInterfaceSetPropertyFunc)    (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *property_name,
                                                         GVariant *value,
                                                         GError **error,
                                                         gpointer user_data);

The type of the set_property function in GDBusInterfaceVTable.

connection :

A GDBusConnection.

sender :

The unique bus name of the remote caller.

object_path :

The object path that the method was invoked on.

interface_name :

The D-Bus interface name for the property.

property_name :

The name of the property to get the value of.

value :

The value to set the property to.

error :

Return location for error.

user_data :

The user_data gpointer passed to g_dbus_connection_register_object().

Returns :

TRUE if the property was set to value, FALSE if error is set.

Since 2.26


g_dbus_connection_register_object ()

guint               g_dbus_connection_register_object   (GDBusConnection *connection,
                                                         const gchar *object_path,
                                                         GDBusInterfaceInfo *interface_info,
                                                         const GDBusInterfaceVTable *vtable,
                                                         gpointer user_data,
                                                         GDestroyNotify user_data_free_func,
                                                         GError **error);

Registers callbacks for exported objects at object_path with the D-Bus interface that is described in interface_info.

Calls to functions in vtable (and user_data_free_func) will happen in the thread-default main loop of the thread you are calling this method from.

Note that all GVariant values passed to functions in vtable will match the signature given in interface_info - if a remote caller passes incorrect values, the org.freedesktop.DBus.Error.InvalidArgs is returned to the remote caller.

Additionally, if the remote caller attempts to invoke methods or access properties not mentioned in interface_info the org.freedesktop.DBus.Error.UnknownMethod resp. org.freedesktop.DBus.Error.InvalidArgs errors are returned to the caller.

It is considered a programming error if the GDBusInterfaceGetPropertyFunc function in vtable returns a GVariant of incorrect type.

If an existing callback is already registered at object_path and interface_name, then error is set to G_IO_ERROR_EXISTS.

GDBus automatically implements the standard D-Bus interfaces org.freedesktop.DBus.Properties, org.freedesktop.DBus.Introspectable and org.freedesktop.Peer, so you don't have to implement those for the objects you export. You can implement org.freedesktop.DBus.Properties yourself, e.g. to handle getting and setting of properties asynchronously.

Note that the reference count on interface_info will be incremented by 1 (unless allocated statically, e.g. if the reference count is -1, see g_dbus_interface_info_ref()) for as long as the object is exported. Also note that vtable will be copied.

See Example 2, “D-Bus server example” for an example of how to use this method.

connection :

A GDBusConnection.

object_path :

The object path to register at.

interface_info :

Introspection data for the interface.

vtable :

A GDBusInterfaceVTable to call into or NULL. [allow-none]

user_data :

Data to pass to functions in vtable. [allow-none]

user_data_free_func :

Function to call when the object path is unregistered.

error :

Return location for error or NULL.

Returns :

0 if error is set, otherwise a registration id (never 0) that can be used with g_dbus_connection_unregister_object() .

Since 2.26


g_dbus_connection_unregister_object ()

gboolean            g_dbus_connection_unregister_object (GDBusConnection *connection,
                                                         guint registration_id);

Unregisters an object.

connection :

A GDBusConnection.

registration_id :

A registration id obtained from g_dbus_connection_register_object().

Returns :

TRUE if the object was unregistered, FALSE otherwise.

Since 2.26


GDBusSubtreeVTable

typedef struct {
  GDBusSubtreeEnumerateFunc  enumerate;
  GDBusSubtreeIntrospectFunc introspect;
  GDBusSubtreeDispatchFunc   dispatch;
} GDBusSubtreeVTable;

Virtual table for handling subtrees registered with g_dbus_connection_register_subtree().

GDBusSubtreeEnumerateFunc enumerate;

Function for enumerating child nodes.

GDBusSubtreeIntrospectFunc introspect;

Function for introspecting a child node.

GDBusSubtreeDispatchFunc dispatch;

Function for dispatching a remote call on a child node.

Since 2.26


GDBusSubtreeEnumerateFunc ()

gchar **            (*GDBusSubtreeEnumerateFunc)        (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         gpointer user_data);

The type of the enumerate function in GDBusSubtreeVTable.

This function is called when generating introspection data and also when preparing to dispatch incoming messages in the event that the G_DBUS_SUBTREE_FLAGS_DISPATCH_TO_UNENUMERATED_NODES flag is not specified (ie: to verify that the object path is valid).

Hierarchies are not supported; the items that you return should not contain the '/' character.

The return value will be freed with g_strfreev().

connection :

A GDBusConnection.

sender :

The unique bus name of the remote caller.

object_path :

The object path that was registered with g_dbus_connection_register_subtree().

user_data :

The user_data gpointer passed to g_dbus_connection_register_subtree().

Returns :

A newly allocated array of strings for node names that are children of object_path.

Since 2.26


GDBusSubtreeIntrospectFunc ()

GDBusInterfaceInfo ** (*GDBusSubtreeIntrospectFunc)     (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *node,
                                                         gpointer user_data);

The type of the introspect function in GDBusSubtreeVTable.

Subtrees are flat. node, if non-NULL, is always exactly one segment of the object path (ie: it never contains a slash).

This function should return NULL to indicate that there is no object at this node.

If this function returns non-NULL, the return value is expected to be a NULL-terminated array of pointers to GDBusInterfaceInfo structures describing the interfaces implemented by node. This array will have g_dbus_interface_info_unref() called on each item before being freed with g_free().

The difference between returning NULL and an array containing zero items is that the standard DBus interfaces will returned to the remote introspector in the empty array case, but not in the NULL case.

connection :

A GDBusConnection.

sender :

The unique bus name of the remote caller.

object_path :

The object path that was registered with g_dbus_connection_register_subtree().

node :

A node that is a child of object_path (relative to object_path) or NULL for the root of the subtree.

user_data :

The user_data gpointer passed to g_dbus_connection_register_subtree().

Returns :

A NULL-terminated array of pointers to GDBusInterfaceInfo, or NULL.

Since 2.26


GDBusSubtreeDispatchFunc ()

const GDBusInterfaceVTable * (*GDBusSubtreeDispatchFunc)
                                                        (GDBusConnection *connection,
                                                         const gchar *sender,
                                                         const gchar *object_path,
                                                         const gchar *interface_name,
                                                         const gchar *node,
                                                         gpointer *out_user_data,
                                                         gpointer user_data);

The type of the dispatch function in GDBusSubtreeVTable.

Subtrees are flat. node, if non-NULL, is always exactly one segment of the object path (ie: it never contains a slash).

connection :

A GDBusConnection.

sender :

The unique bus name of the remote caller.

object_path :

The object path that was registered with g_dbus_connection_register_subtree().

interface_name :

The D-Bus interface name that the method call or property access is for.

node :

A node that is a child of object_path (relative to object_path) or NULL for the root of the subtree.

out_user_data :

Return location for user data to pass to functions in the returned GDBusInterfaceVTable (never NULL).

user_data :

The user_data gpointer passed to g_dbus_connection_register_subtree().

Returns :

A GDBusInterfaceVTable or NULL if you don't want to handle the methods.

Since 2.26


enum GDBusSubtreeFlags

typedef enum {
  G_DBUS_SUBTREE_FLAGS_NONE = 0,
  G_DBUS_SUBTREE_FLAGS_DISPATCH_TO_UNENUMERATED_NODES = (1<<0)
} GDBusSubtreeFlags;

Flags passed to g_dbus_connection_register_subtree().

G_DBUS_SUBTREE_FLAGS_NONE

No flags set.

G_DBUS_SUBTREE_FLAGS_DISPATCH_TO_UNENUMERATED_NODES

Method calls to objects not in the enumerated range will still be dispatched. This is useful if you want to dynamically spawn objects in the subtree.

Since 2.26


g_dbus_connection_register_subtree ()

guint               g_dbus_connection_register_subtree  (GDBusConnection *connection,
                                                         const gchar *object_path,
                                                         const GDBusSubtreeVTable *vtable,
                                                         GDBusSubtreeFlags flags,
                                                         gpointer user_data,
                                                         GDestroyNotify user_data_free_func,
                                                         GError **error);

Registers a whole subtree of dynamic objects.

The enumerate and introspection functions in vtable are used to convey, to remote callers, what nodes exist in the subtree rooted by object_path.

When handling remote calls into any node in the subtree, first the enumerate function is used to check if the node exists. If the node exists or the G_DBUS_SUBTREE_FLAGS_DISPATCH_TO_UNENUMERATED_NODES flag is set the introspection function is used to check if the node supports the requested method. If so, the dispatch function is used to determine where to dispatch the call. The collected GDBusInterfaceVTable and gpointer will be used to call into the interface vtable for processing the request.

All calls into user-provided code will be invoked in the thread-default main loop of the thread you are calling this method from.

If an existing subtree is already registered at object_path or then error is set to G_IO_ERROR_EXISTS.

Note that it is valid to register regular objects (using g_dbus_connection_register_object()) in a subtree registered with g_dbus_connection_register_subtree() - if so, the subtree handler is tried as the last resort. One way to think about a subtree handler is to consider it a fallback handler for object paths not registered via g_dbus_connection_register_object() or other bindings.

Note that vtable will be copied so you cannot change it after registration.

See Example 3, “D-Bus subtree example” for an example of how to use this method.

connection :

A GDBusConnection.

object_path :

The object path to register the subtree at.

vtable :

A GDBusSubtreeVTable to enumerate, introspect and dispatch nodes in the subtree.

flags :

Flags used to fine tune the behavior of the subtree.

user_data :

Data to pass to functions in vtable.

user_data_free_func :

Function to call when the subtree is unregistered.

error :

Return location for error or NULL.

Returns :

0 if error is set, otherwise a subtree registration id (never 0) that can be used with g_dbus_connection_unregister_subtree() .

Since 2.26


g_dbus_connection_unregister_subtree ()

gboolean            g_dbus_connection_unregister_subtree
                                                        (GDBusConnection *connection,
                                                         guint registration_id);

Unregisters a subtree.

connection :

A GDBusConnection.

registration_id :

A subtree registration id obtained from g_dbus_connection_register_subtree().

Returns :

TRUE if the subtree was unregistered, FALSE otherwise.

Since 2.26

Property Details

The "address" property

  "address"                  gchar*                : Write / Construct Only

A D-Bus address specifying potential endpoints that can be used when establishing the connection.

Default value: NULL

Since 2.26


The "authentication-observer" property

  "authentication-observer"  GDBusAuthObserver*    : Write / Construct Only

A GDBusAuthObserver object to assist in the authentication process or NULL.

Since 2.26


The "capabilities" property

  "capabilities"             GDBusCapabilityFlags  : Read

Flags from the GDBusCapabilityFlags enumeration representing connection features negotiated with the other peer.

Since 2.26


The "closed" property

  "closed"                   gboolean              : Read

A boolean specifying whether the connection has been closed.

Default value: FALSE

Since 2.26


The "exit-on-close" property

  "exit-on-close"            gboolean              : Read / Write

A boolean specifying whether the process will be terminated (by calling raise(SIGTERM)) if the connection is closed by the remote peer.

Note that GDBusConnection objects returned by g_bus_get_finish() and g_bus_get_sync() will (usually) have this property set to TRUE.

Default value: FALSE

Since 2.26


The "flags" property

  "flags"                    GDBusConnectionFlags  : Write / Construct Only

Flags from the GDBusConnectionFlags enumeration.

Since 2.26


The "guid" property

  "guid"                     gchar*                : Read / Write / Construct Only

The GUID of the peer performing the role of server when authenticating.

If you are constructing a GDBusConnection and pass G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_SERVER in the "flags" property then you MUST also set this property to a valid guid.

If you are constructing a GDBusConnection and pass G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_CLIENT in the "flags" property you will be able to read the GUID of the other peer here after the connection has been successfully initialized.

Default value: NULL

Since 2.26


The "stream" property

  "stream"                   GIOStream*            : Read / Write / Construct Only

The underlying GIOStream used for I/O.

If this is passed on construction and is a GSocketConnection, then the corresponding GSocket will be put into non-blocking mode.

While the GDBusConnection is active, it will interact with this stream from a worker thread, so it is not safe to interact with the stream directly.

Since 2.26


The "unique-name" property

  "unique-name"              gchar*                : Read

The unique name as assigned by the message bus or NULL if the connection is not open or not a message bus connection.

Default value: NULL

Since 2.26

Signal Details

The "closed" signal

void                user_function                      (GDBusConnection *connection,
                                                        gboolean         remote_peer_vanished,
                                                        GError          *error,
                                                        gpointer         user_data)                 : Run Last

Emitted when the connection is closed.

The cause of this event can be

  • If g_dbus_connection_close() is called. In this case remote_peer_vanished is set to FALSE and error is NULL.

  • If the remote peer closes the connection. In this case remote_peer_vanished is set to TRUE and error is set.

  • If the remote peer sends invalid or malformed data. In this case remote_peer_vanished is set to FALSE and error is set.

Upon receiving this signal, you should give up your reference to connection. You are guaranteed that this signal is emitted only once.

connection :

The GDBusConnection emitting the signal.

remote_peer_vanished :

TRUE if connection is closed because the remote peer closed its end of the connection.

error :

A GError with more details about the event or NULL.

user_data :

user data set when the signal handler was connected.

Since 2.26



[1] This is so that g_bus_get() and g_bus_get_sync() can safely return the same GDBusConnection when called from any thread.