Owning Bus Names: GIO Reference Manual

## Owning Bus Names Owning Bus Names — Simple API for owning bus names |

## Functions

void | (*GBusAcquiredCallback) ()
void | (*GBusNameAcquiredCallback) ()
void | (*GBusNameLostCallback) ()
guint | g_bus_own_name ()
guint | g_bus_own_name_on_connection ()
void | g_bus_unown_name ()
guint | g_bus_own_name_with_closures ()
guint | g_bus_own_name_on_connection_with_closures ()

## Types and Values

enum | GBusNameOwnerFlags

## Includes

    #include <gio/gio.h>

## Description

Convenience API for owning bus names.

A simple example for owning a name can be found in gdbus-example-own-name.c

## Functions

### GBusAcquiredCallback ()

    void
    (*GBusAcquiredCallback) (GDBusConnection *connection,
                             const gchar *name,
                             gpointer user_data);

Invoked when a connection to a message bus has been obtained.

#### Parameters

connection | The GDBusConnection to a message bus. |
name | The name that is requested to be owned. |
user_data | User data passed to `g_bus_own_name()`. |

Since: 2.26

### GBusNameAcquiredCallback ()

    void
    (*GBusNameAcquiredCallback) (GDBusConnection *connection,
                                 const gchar *name,
                                 gpointer user_data);

Invoked when the name is acquired.

#### Parameters

connection | The GDBusConnection on which to acquired the name. |
name | The name being owned. |
user_data | User data passed to `g_bus_own_name()` or `g_bus_own_name_on_connection()`. |

Since: 2.26

### GBusNameLostCallback ()

    void
    (*GBusNameLostCallback) (GDBusConnection *connection,
                             const gchar *name,
                             gpointer user_data);

Invoked when the name is lost or `connection` has been closed.

#### Parameters

connection | The GDBusConnection on which to acquire the name or `NULL` if the connection was disconnected. |
name | The name being owned. |
user_data | User data passed to `g_bus_own_name()` or `g_bus_own_name_on_connection()`. |

Since: 2.26

### g_bus_own_name ()

    guint
    g_bus_own_name (GBusType bus_type,
                    const gchar *name,
                    GBusNameOwnerFlags flags,
                    GBusAcquiredCallback bus_acquired_handler,
                    GBusNameAcquiredCallback name_acquired_handler,
                    GBusNameLostCallback name_lost_handler,
                    gpointer user_data,
                    GDestroyNotify user_data_free_func);

Starts acquiring `name` on the bus specified by `bus_type` and calls `name_acquired_handler` and `name_lost_handler` when the name is acquired respectively lost. Callbacks will be invoked in the thread-default main context of the thread you are calling this function from.

You are guaranteed that one of the `name_acquired_handler` and `name_lost_handler` callbacks will be invoked after calling this function - there are three possible cases:

- `name_lost_handler` with a `NULL` connection (if a connection to the bus can't be made).

- `bus_acquired_handler` then `name_lost_handler` (if the name can't be obtained)

- `bus_acquired_handler` then `name_acquired_handler` (if the name was obtained).

When you are done owning the name, just call `g_bus_unown_name()` with the owner id this function returns.

If the name is acquired or lost (for example another application could acquire the name if you allow replacement or the application currently owning the name exits), the handlers are also invoked. If the GDBusConnection that is used for attempting to own the name closes, then `name_lost_handler` is invoked since it is no longer possible for other processes to access the process.

You cannot use `g_bus_own_name()` several times for the same name (unless interleaved with calls to `g_bus_unown_name()`) - only the first call will work.

Another guarantee is that invocations of `name_acquired_handler` and `name_lost_handler` are guaranteed to alternate; that is, if `name_acquired_handler` is invoked then you are guaranteed that the next time one of the handlers is invoked, it will be `name_lost_handler` . The reverse is also true.

If you plan on exporting objects (using e.g. `g_dbus_connection_register_object()`), note that it is generally too late to export the objects in `name_acquired_handler` . Instead, you can do this in `bus_acquired_handler` since you are guaranteed that this will run before `name` is requested from the bus.

This behavior makes it very simple to write applications that wants to own names and export objects. Simply register objects to be exported in `bus_acquired_handler` and unregister the objects (if any) in `name_lost_handler` .

#### Parameters

bus_type | the type of bus to own a name on |
name | the well-known name to own |
flags | a set of flags from the GBusNameOwnerFlags enumeration |
bus_acquired_handler | handler to invoke when connected to the bus of type `bus_type` or `NULL`. | [nullable]
name_acquired_handler | handler to invoke when `name` is acquired or `NULL`. | [nullable]
name_lost_handler | handler to invoke when `name` is lost or `NULL`. | [nullable]
user_data | user data to pass to handlers |
user_data_free_func | function for freeing `user_data` or `NULL`. | [nullable]

#### Returns

an identifier (never 0) that an be used with `g_bus_unown_name()` to stop owning the name.

Since: 2.26

### g_bus_own_name_on_connection ()

    guint
    g_bus_own_name_on_connection (GDBusConnection *connection,
                                  const gchar *name,
                                  GBusNameOwnerFlags flags,
                                  GBusNameAcquiredCallback name_acquired_handler,
                                  GBusNameLostCallback name_lost_handler,
                                  gpointer user_data,
                                  GDestroyNotify user_data_free_func);

Like `g_bus_own_name()` but takes a GDBusConnection instead of a GBusType.

#### Parameters

connection | a GDBusConnection |
name | the well-known name to own |
flags | a set of flags from the GBusNameOwnerFlags enumeration |
name_acquired_handler | handler to invoke when `name` is acquired or `NULL`. | [nullable]
name_lost_handler | handler to invoke when `name` is lost or `NULL`. | [nullable]
user_data | user data to pass to handlers |
user_data_free_func | function for freeing `user_data` or `NULL`. | [nullable]

#### Returns

an identifier (never 0) that an be used with `g_bus_unown_name()` to stop owning the name

Since: 2.26

### g_bus_unown_name ()

    void
    g_bus_unown_name (guint owner_id);

Stops owning a name.

#### Parameters

owner_id | an identifier obtained from `g_bus_own_name()` |

Since: 2.26

### g_bus_own_name_with_closures ()

    guint
    g_bus_own_name_with_closures (GBusType bus_type,
                                  const gchar *name,
                                  GBusNameOwnerFlags flags,
                                  GClosure *bus_acquired_closure,
                                  GClosure *name_acquired_closure,
                                  GClosure *name_lost_closure);

Version of `g_bus_own_name()` using closures instead of callbacks for easier binding in other languages.

[rename-to g_bus_own_name]

#### Parameters

bus_type | the type of bus to own a name on |
name | the well-known name to own |
flags | a set of flags from the GBusNameOwnerFlags enumeration |
bus_acquired_closure | GClosure to invoke when connected to the bus of type `bus_type` or `NULL`. | [nullable]
name_acquired_closure | GClosure to invoke when `name` is acquired or `NULL`. | [nullable]
name_lost_closure | GClosure to invoke when `name` is lost or `NULL`. | [nullable]

#### Returns

an identifier (never 0) that an be used with `g_bus_unown_name()` to stop owning the name.

Since: 2.26

### g_bus_own_name_on_connection_with_closures ()

    guint
    g_bus_own_name_on_connection_with_closures
                                   (GDBusConnection *connection,
                                    const gchar *name,
                                    GBusNameOwnerFlags flags,
                                    GClosure *name_acquired_closure,
                                    GClosure *name_lost_closure);

Version of `g_bus_own_name_on_connection()` using closures instead of callbacks for easier binding in other languages.

[rename-to g_bus_own_name_on_connection]

#### Parameters

connection | a GDBusConnection |
name | the well-known name to own |
flags | a set of flags from the GBusNameOwnerFlags enumeration |
name_acquired_closure | GClosure to invoke when `name` is acquired or `NULL`. | [nullable]
name_lost_closure | GClosure to invoke when `name` is lost or `NULL`. | [nullable]

#### Returns

an identifier (never 0) that an be used with `g_bus_unown_name()` to stop owning the name.

Since: 2.26

## Types and Values

### enum GBusNameOwnerFlags

Flags used in `g_bus_own_name()`.

#### Members

G_BUS_NAME_OWNER_FLAGS_NONE | No flags set. |
G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT | Allow another message bus connection to claim the name. |
G_BUS_NAME_OWNER_FLAGS_REPLACE | If another message bus connection owns the name and have specified G_BUS_NAME_OWNER_FLAGS_ALLOW_REPLACEMENT, then take the name from the other connection. |
G_BUS_NAME_OWNER_FLAGS_DO_NOT_QUEUE | If another message bus connection owns the name, immediately return an error from `g_bus_own_name()` rather than entering the waiting queue for that name. (Since 2.54) |

Since: 2.26