Gio.DBusConnection¶

class — extends GObject.Object, AsyncInitable, Initable

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 a IOStream.

This class is rarely used directly in D-Bus clients. If you are writing a D-Bus client, it is often easier to use the bus_own_name, bus_watch_name or DBusProxy.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, GDBusConnections methods may be called from any thread. This is so that bus_get and bus_get_sync can safely return the same GDBusConnection when called from any thread.

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

If you construct an uninitialized GDBusConnection, such as via GObject.Object.new, you must initialize it via Initable.init or AsyncInitable.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 GObject.Object.unref.

An example D-Bus server¶

Here is an example for a D-Bus server: gdbus-example-server.c

An example for exporting a subtree¶

Here is an example for exporting a subtree: gdbus-example-subtree.c

An example for file descriptor passing¶

Here is an example for passing UNIX file descriptors: gdbus-unix-fd-client.c

An example for exporting a GObject¶

Here is an example for exporting a GObject.Object: gdbus-example-export.c

Constructors¶

new_finish¶

@classmethod
def new_finish(cls, res: AsyncResult) -> DBusConnection

Finishes an operation started with DBusConnection.new.

Parameters:

res — a AsyncResult obtained from the GAsyncReadyCallback passed to DBusConnection.new.

new_for_address_finish¶

@classmethod
def new_for_address_finish(cls, res: AsyncResult) -> DBusConnection

Finishes an operation started with DBusConnection.new_for_address.

Parameters:

res — a AsyncResult obtained from the GAsyncReadyCallback passed to DBusConnection.new

new_for_address_sync¶

@classmethod
def new_for_address_sync(cls, address: str, flags: DBusConnectionFlags | int, observer: DBusAuthObserver | None = ..., cancellable: Cancellable | None = ...) -> DBusConnection

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 DBusConnection.new_sync if you need to act as the server. In particular, flags cannot contain the DBusConnectionFlags.AUTHENTICATION_SERVER, DBusConnectionFlags.AUTHENTICATION_ALLOW_ANONYMOUS or DBusConnectionFlags.AUTHENTICATION_REQUIRE_SAME_USER flags.

This is a synchronous failable constructor. See DBusConnection.new_for_address for the asynchronous version.

If observer is not None it may be used to control the authentication process.

Parameters:

address — a D-Bus address
flags — flags describing how to make the connection
observer — a DBusAuthObserver or None
cancellable — a Cancellable or None

new_sync¶

@classmethod
def new_sync(cls, stream: IOStream, guid: str | None, flags: DBusConnectionFlags | int, observer: DBusAuthObserver | None = ..., cancellable: Cancellable | None = ...) -> DBusConnection

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

If stream is a SocketConnection, then the corresponding Socket 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 GObject.Object.unref on it.

If observer is not None it may be used to control the authentication process.

This is a synchronous failable constructor. See DBusConnection.new for the asynchronous version.

Parameters:

stream — a IOStream
guid — the GUID to use if authenticating as a server or None
flags — flags describing how to make the connection
observer — a DBusAuthObserver or None
cancellable — a Cancellable or None

Methods¶

add_filter¶

def add_filter(self, filter_function: DBusMessageFilterFunction) -> int

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 DBusConnection.send_message_with_reply, DBusConnection.signal_subscribe or DBusConnection.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 DBusConnection.signal_subscribe and DBusConnection.send_message_with_reply relies on) will see the message. Similarly, if a filter consumes an outgoing message, the message will not be sent to the other peer.

If user_data_free_func is non-None, it will be called (in the thread-default main context of the thread you are calling this method from) at some point after user_data is no longer needed. (It is not guaranteed to be called synchronously when the filter is removed, and may be called after connection has been destroyed.)

Parameters:

filter_function — a filter function

call¶

def call(self, bus_name: str | None, object_path: str, interface_name: str, method_name: str, parameters: GLib.Variant | None, reply_type: GLib.VariantType | None, flags: DBusCallFlags | int, timeout_msec: int, cancellable: Cancellable | None = ..., callback: Callable[[DBusConnection | None, AsyncResult], None] | None = ...) -> None

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 IOErrorEnum.CLOSED. If cancellable is canceled, the operation will fail with IOErrorEnum.CANCELLED. If parameters contains a value not compatible with the D-Bus protocol, the operation fails with IOErrorEnum.INVALID_ARGUMENT.

If reply_type is non-None 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-None return value will be of this type. Unless it’s G_VARIANT_TYPE_UNIT, the reply_type will be a tuple containing one or more values.

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

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 context (see GLib.MainContext.push_thread_default) of the thread you are calling this method from. You can then call DBusConnection.call_finish to get the result of the operation. See DBusConnection.call_sync for the synchronous version of this function.

If callback is None then the D-Bus method call message will be sent with the DBusMessageFlags.NO_REPLY_EXPECTED flag set.

Parameters:

bus_name — a unique or well-known bus name or None if connection is not a message bus connection
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 GLib.Variant tuple with parameters for the method or None if not passing parameters
reply_type — the expected type of the reply (which will be a tuple), or None
flags — flags from the DBusCallFlags enumeration
timeout_msec — the timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout
cancellable — a Cancellable or None
callback — a GAsyncReadyCallback to call when the request is satisfied or None if you don't care about the result of the method invocation

call_finish¶

def call_finish(self, res: AsyncResult) -> GLib.Variant

Finishes an operation started with DBusConnection.call.

Parameters:

res — a AsyncResult obtained from the GAsyncReadyCallback passed to DBusConnection.call

call_sync¶

def call_sync(self, bus_name: str | None, object_path: str, interface_name: str, method_name: str, parameters: GLib.Variant | None, reply_type: GLib.VariantType | None, flags: DBusCallFlags | int, timeout_msec: int, cancellable: Cancellable | None = ...) -> GLib.Variant

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 IOErrorEnum.CLOSED. If cancellable is canceled, the operation will fail with IOErrorEnum.CANCELLED. If parameters contains a value not compatible with the D-Bus protocol, the operation fails with IOErrorEnum.INVALID_ARGUMENT.

If reply_type is non-None 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-None return value will be of this type.

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

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 DBusConnection.call for the asynchronous version of this method.

Parameters:

bus_name — a unique or well-known bus name or None if connection is not a message bus connection
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 GLib.Variant tuple with parameters for the method or None if not passing parameters
reply_type — the expected type of the reply, or None
flags — flags from the DBusCallFlags enumeration
timeout_msec — the timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout
cancellable — a Cancellable or None

call_with_unix_fd_list¶

def call_with_unix_fd_list(self, bus_name: str | None, object_path: str, interface_name: str, method_name: str, parameters: GLib.Variant | None, reply_type: GLib.VariantType | None, flags: DBusCallFlags | int, timeout_msec: int, fd_list: UnixFDList | None = ..., cancellable: Cancellable | None = ..., callback: Callable[[DBusConnection | None, AsyncResult], None] | None = ...) -> None

Like DBusConnection.call but also takes a UnixFDList object.

The file descriptors normally correspond to G_VARIANT_TYPE_HANDLE values in the body of the message. For example, if a message contains two file descriptors, fd_list would have length 2, and g_variant_new_handle (0) and g_variant_new_handle (1) would appear somewhere in the body of the message (not necessarily in that order!) to represent the file descriptors at indexes 0 and 1 respectively.

When designing D-Bus APIs that are intended to be interoperable, please note that non-GDBus implementations of D-Bus can usually only access file descriptors if they are referenced in this way by a value of type G_VARIANT_TYPE_HANDLE in the body of the message.

This method is only available on UNIX.

Parameters:

bus_name — a unique or well-known bus name or None if connection is not a message bus connection
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 GLib.Variant tuple with parameters for the method or None if not passing parameters
reply_type — the expected type of the reply, or None
flags — flags from the DBusCallFlags enumeration
timeout_msec — the timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout
fd_list — a UnixFDList or None
cancellable — a Cancellable or None
callback — a GAsyncReadyCallback to call when the request is satisfied or None if you don't * care about the result of the method invocation

call_with_unix_fd_list_finish¶

def call_with_unix_fd_list_finish(self, res: AsyncResult) -> tuple[GLib.Variant, UnixFDList]

Finishes an operation started with DBusConnection.call_with_unix_fd_list.

The file descriptors normally correspond to G_VARIANT_TYPE_HANDLE values in the body of the message. For example, if GLib.Variant.get_handle returns 5, that is intended to be a reference to the file descriptor that can be accessed by g_unix_fd_list_get (*out_fd_list, 5, ...).

When designing D-Bus APIs that are intended to be interoperable, please note that non-GDBus implementations of D-Bus can usually only access file descriptors if they are referenced in this way by a value of type G_VARIANT_TYPE_HANDLE in the body of the message.

Parameters:

res — a AsyncResult obtained from the GAsyncReadyCallback passed to DBusConnection.call_with_unix_fd_list

call_with_unix_fd_list_sync¶

def call_with_unix_fd_list_sync(self, bus_name: str | None, object_path: str, interface_name: str, method_name: str, parameters: GLib.Variant | None, reply_type: GLib.VariantType | None, flags: DBusCallFlags | int, timeout_msec: int, fd_list: UnixFDList | None = ..., cancellable: Cancellable | None = ...) -> tuple[GLib.Variant, UnixFDList]

Like DBusConnection.call_sync but also takes and returns UnixFDList objects. See DBusConnection.call_with_unix_fd_list and DBusConnection.call_with_unix_fd_list_finish for more details.

This method is only available on UNIX.

Parameters:

bus_name — a unique or well-known bus name or None if connection is not a message bus connection
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 GLib.Variant tuple with parameters for the method or None if not passing parameters
reply_type — the expected type of the reply, or None
flags — flags from the DBusCallFlags enumeration
timeout_msec — the timeout in milliseconds, -1 to use the default timeout or G_MAXINT for no timeout
fd_list — a UnixFDList or None
cancellable — a Cancellable or None

close¶

def close(self, cancellable: Cancellable | None = ..., callback: Callable[[DBusConnection | None, AsyncResult], None] | None = ...) -> None

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 DBusConnection:exit-on-close).

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

If connection is already closed, this method fails with IOErrorEnum.CLOSED.

When connection has been closed, the DBusConnection::closed signal is emitted in the thread-default main context (see GLib.MainContext.push_thread_default) 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 context (see GLib.MainContext.push_thread_default) of the thread you are calling this method from. You can then call DBusConnection.close_finish to get the result of the operation. See DBusConnection.close_sync for the synchronous version.

Parameters:

cancellable — a Cancellable or None
callback — a GAsyncReadyCallback to call when the request is satisfied or None if you don't care about the result

close_finish¶

def close_finish(self, res: AsyncResult) -> bool

Finishes an operation started with DBusConnection.close.

Parameters:

res — a AsyncResult obtained from the GAsyncReadyCallback passed to DBusConnection.close

close_sync¶

def close_sync(self, cancellable: Cancellable | None = ...) -> bool

Synchronously closes connection. The calling thread is blocked until this is done. See DBusConnection.close for the asynchronous version of this method and more details about what it does.

Parameters:

cancellable — a Cancellable or None

emit_signal¶

def emit_signal(self, destination_bus_name: str | None, object_path: str, interface_name: str, signal_name: str, parameters: GLib.Variant | None = ...) -> bool

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 (IOErrorEnum.INVALID_ARGUMENT), or if connection has been closed (IOErrorEnum.CLOSED).

Parameters:

destination_bus_name — the unique bus name for the destination for the signal or None to emit to all listeners
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 GLib.Variant tuple with parameters for the signal or None if not passing parameters

export_action_group¶

def export_action_group(self, object_path: str, action_group: ActionGroup) -> int

Exports action_group on connection at object_path.

The implemented D-Bus API should be considered private. It is subject to change in the future.

A given object path can only have one action group exported on it. If this constraint is violated, the export will fail and 0 will be returned (with error set accordingly).

You can unexport the action group using DBusConnection.unexport_action_group with the return value of this function.

The thread default main context is taken at the time of this call. All incoming action activations and state change requests are reported from this context. Any changes on the action group that cause it to emit signals must also come from this same context. Since incoming action activations and state change requests are rather likely to cause changes on the action group, this effectively limits a given action group to being exported from only one main context.

Parameters:

object_path — a D-Bus object path
action_group — an action group

export_menu_model¶

def export_menu_model(self, object_path: str, menu: MenuModel) -> int

Exports menu on connection at object_path.

The implemented D-Bus API should be considered private. It is subject to change in the future.

An object path can only have one menu model exported on it. If this constraint is violated, the export will fail and 0 will be returned (with error set accordingly).

Exporting menus with sections containing more than MENU_EXPORTER_MAX_SECTION_SIZE items is not supported and results in undefined behavior.

You can unexport the menu model using DBusConnection.unexport_menu_model with the return value of this function.

Parameters:

object_path — a D-Bus object path
menu — a MenuModel

flush¶

def flush(self, cancellable: Cancellable | None = ..., callback: Callable[[DBusConnection | None, AsyncResult], None] | None = ...) -> None

Asynchronously flushes connection, that is, writes all queued outgoing messages to the transport and then flushes the transport (using OutputStream.flush_async). This is useful in programs that want 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 context (see GLib.MainContext.push_thread_default) of the thread you are calling this method from. You can then call DBusConnection.flush_finish to get the result of the operation. See DBusConnection.flush_sync for the synchronous version.

Parameters:

cancellable — a Cancellable or None
callback — a GAsyncReadyCallback to call when the request is satisfied or None if you don't care about the result

flush_finish¶

def flush_finish(self, res: AsyncResult) -> bool

Finishes an operation started with DBusConnection.flush.

Parameters:

res — a AsyncResult obtained from the GAsyncReadyCallback passed to DBusConnection.flush

flush_sync¶

def flush_sync(self, cancellable: Cancellable | None = ...) -> bool

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

Parameters:

cancellable — a Cancellable or None

get_capabilities¶

def get_capabilities(self) -> DBusCapabilityFlags

Gets the capabilities negotiated with the remote peer

get_exit_on_close¶

def get_exit_on_close(self) -> bool

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

get_flags¶

def get_flags(self) -> DBusConnectionFlags

Gets the flags used to construct this connection

get_guid¶

def get_guid(self) -> str

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

get_last_serial¶

def get_last_serial(self) -> int

Retrieves the last serial number assigned to a DBusMessage on the current thread. This includes messages sent via both low-level API such as DBusConnection.send_message as well as high-level API such as DBusConnection.emit_signal, DBusConnection.call or DBusProxy.call.

get_peer_credentials¶

def get_peer_credentials(self) -> Credentials | None

Gets the credentials of the authenticated peer. This will always return None unless connection acted as a server (e.g. DBusConnectionFlags.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 None for message bus clients.

get_stream¶

def get_stream(self) -> IOStream

Gets the underlying stream used for IO.

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

get_unique_name¶

def get_unique_name(self) -> str | None

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.

is_closed¶

def is_closed(self) -> bool

Gets whether connection is closed.

register_object¶

def register_object(self, object_path: str, interface_info: DBusInterfaceInfo, vtable: DBusInterfaceVTable | None, user_data: int | None, user_data_free_func: GLib.DestroyNotify) -> int

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 context (see GLib.MainContext.push_thread_default) of the thread you are calling this method from.

Note that all GLib.Variant 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 GLib.Variant of incorrect type.

If an existing callback is already registered at object_path and interface_name, then error is set to IOErrorEnum.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 DBusInterfaceInfo.ref) for as long as the object is exported. Also note that vtable will be copied.

See this [server][classGio.DBusConnection#an-example-d-bus-server] for an example of how to use this method.

Parameters:

object_path — the object path to register at
interface_info — introspection data for the interface
vtable — a DBusInterfaceVTable to call into or None
user_data — data to pass to functions in vtable
user_data_free_func — function to call when the object path is unregistered

register_object_with_closures¶

def register_object_with_closures(self, object_path: str, interface_info: DBusInterfaceInfo, method_call_closure: GObject.Closure | None = ..., get_property_closure: GObject.Closure | None = ..., set_property_closure: GObject.Closure | None = ...) -> int

:::warning Deprecated since 2.84 This API is deprecated. :::

Version of DBusConnection.register_object using closures instead of a DBusInterfaceVTable for easier binding in other languages.

Note that the reference counting semantics of the function wrapped by method_call_closure are the same as those of DBusInterfaceMethodCallFunc: ownership of a reference to the DBusMethodInvocation is transferred to the function.

Parameters:

object_path — The object path to register at.
interface_info — Introspection data for the interface.
method_call_closure — GObject.Closure for handling incoming method calls.
get_property_closure — GObject.Closure for getting a property.
set_property_closure — GObject.Closure for setting a property.

register_object_with_closures2¶

def register_object_with_closures2(self, object_path: str, interface_info: DBusInterfaceInfo, method_call_closure: GObject.Closure | None = ..., get_property_closure: GObject.Closure | None = ..., set_property_closure: GObject.Closure | None = ...) -> int

Version of DBusConnection.register_object using closures instead of a DBusInterfaceVTable for easier binding in other languages.

In contrast to DBusConnection.register_object and DBusConnection.register_object_with_closures, the reference counting semantics of the function wrapped by method_call_closure are not the same as those of DBusInterfaceMethodCallFunc. Ownership of a reference to the DBusMethodInvocation is not transferred to the function. Bindings must ensure that they add a reference to the DBusMethodInvocation before calling any g_dbus_method_invocation_return_*() methods on it. This should be automatic as a result of the introspection annotations on those methods.

Parameters:

object_path — The object path to register at.
interface_info — Introspection data for the interface.
method_call_closure — GObject.Closure for handling incoming method calls.
get_property_closure — GObject.Closure for getting a property.
set_property_closure — GObject.Closure for setting a property.

register_subtree¶

def register_subtree(self, object_path: str, vtable: DBusSubtreeVTable, flags: DBusSubtreeFlags | int, user_data: int | None, user_data_free_func: GLib.DestroyNotify) -> int

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 DBusSubtreeFlags.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 DBusInterfaceVTable 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 context (see GLib.MainContext.push_thread_default) 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 IOErrorEnum.EXISTS.

Note that it is valid to register regular objects (using DBusConnection.register_object) in a subtree registered with DBusConnection.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 DBusConnection.register_object or other bindings.

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

See this [server][classGio.DBusConnection#an-example-for-exporting-a-subtree] for an example of how to use this method.

Parameters:

object_path — the object path to register the subtree at
vtable — a DBusSubtreeVTable 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

remove_filter¶

def remove_filter(self, filter_id: int) -> None

Removes a filter.

Note that since filters run in a different thread, there is a race condition where it is possible that the filter will be running even after calling DBusConnection.remove_filter, so you cannot just free data that the filter might be using. Instead, you should pass a GDestroyNotify to DBusConnection.add_filter, which will be called when it is guaranteed that the data is no longer needed.

Parameters:

filter_id — an identifier obtained from DBusConnection.add_filter

send_message¶

def send_message(self, message: DBusMessage, flags: DBusSendMessageFlags | int) -> tuple[bool, int]

Asynchronously sends message to the peer represented by connection.

Unless flags contain the DBusSendMessageFlags.PRESERVE_SERIAL flag, the serial number will be assigned by connection and set on message via DBusMessage.set_serial. If out_serial is not None, then the serial number used will be written to this location prior to submitting the message to the underlying transport. While it has a volatile qualifier, this is a historical artifact and the argument passed to it should not be volatile.

If connection is closed then the operation will fail with IOErrorEnum.CLOSED. If message is not well-formed, the operation fails with IOErrorEnum.INVALID_ARGUMENT.

See this [server][classGio.DBusConnection#an-example-d-bus-server] and [client][classGio.DBusConnection#an-example-for-file-descriptor-passing] 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 DBusSendMessageFlags.PRESERVE_SERIAL flag.

Parameters:

message — a DBusMessage
flags — flags affecting how the message is sent

send_message_with_reply¶

def send_message_with_reply(self, message: DBusMessage, flags: DBusSendMessageFlags | int, timeout_msec: int, cancellable: Cancellable | None = ..., callback: Callable[[DBusConnection | None, AsyncResult], None] | None = ...) -> int

Asynchronously sends message to the peer represented by connection.

Unless flags contain the DBusSendMessageFlags.PRESERVE_SERIAL flag, the serial number will be assigned by connection and set on message via DBusMessage.set_serial. If out_serial is not None, then the serial number used will be written to this location prior to submitting the message to the underlying transport. While it has a volatile qualifier, this is a historical artifact and the argument passed to it should not be volatile.

If connection is closed then the operation will fail with IOErrorEnum.CLOSED. If cancellable is canceled, the operation will fail with IOErrorEnum.CANCELLED. If message is not well-formed, the operation fails with IOErrorEnum.INVALID_ARGUMENT.

This is an asynchronous method. When the operation is finished, callback will be invoked in the thread-default main context (see GLib.MainContext.push_thread_default) of the thread you are calling this method from. You can then call DBusConnection.send_message_with_reply_finish to get the result of the operation. See DBusConnection.send_message_with_reply_sync for the synchronous version.

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

See this [server][classGio.DBusConnection#an-example-d-bus-server] and [client][classGio.DBusConnection#an-example-for-file-descriptor-passing] for an example of how to use this low-level API to send and receive UNIX file descriptors.

Parameters:

message — a DBusMessage
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
cancellable — a Cancellable or None
callback — a GAsyncReadyCallback to call when the request is satisfied or None if you don't care about the result

send_message_with_reply_finish¶

def send_message_with_reply_finish(self, res: AsyncResult) -> DBusMessage

Finishes an operation started with DBusConnection.send_message_with_reply.

Note that error is only set if a local in-process error occurred. That is to say that the returned DBusMessage object may be of type DBusMessageType.ERROR. Use DBusMessage.to_gerror to transcode this to a GLib.Error.

See this [server][classGio.DBusConnection#an-example-d-bus-server] and [client][classGio.DBusConnection#an-example-for-file-descriptor-passing] for an example of how to use this low-level API to send and receive UNIX file descriptors.

Parameters:

res — a AsyncResult obtained from the GAsyncReadyCallback passed to DBusConnection.send_message_with_reply

send_message_with_reply_sync¶

def send_message_with_reply_sync(self, message: DBusMessage, flags: DBusSendMessageFlags | int, timeout_msec: int, cancellable: Cancellable | None = ...) -> tuple[DBusMessage, int]

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 DBusConnection.send_message_with_reply for the asynchronous version of this method.

Unless flags contain the DBusSendMessageFlags.PRESERVE_SERIAL flag, the serial number will be assigned by connection and set on message via DBusMessage.set_serial. If out_serial is not None, then the serial number used will be written to this location prior to submitting the message to the underlying transport. While it has a volatile qualifier, this is a historical artifact and the argument passed to it should not be volatile.

If connection is closed then the operation will fail with IOErrorEnum.CLOSED. If cancellable is canceled, the operation will fail with IOErrorEnum.CANCELLED. If message is not well-formed, the operation fails with IOErrorEnum.INVALID_ARGUMENT.

Note that error is only set if a local in-process error occurred. That is to say that the returned DBusMessage object may be of type DBusMessageType.ERROR. Use DBusMessage.to_gerror to transcode this to a GLib.Error.

See this [server][classGio.DBusConnection#an-example-d-bus-server] and [client][classGio.DBusConnection#an-example-for-file-descriptor-passing] 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 DBusSendMessageFlags.PRESERVE_SERIAL flag.

Parameters:

message — a DBusMessage
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
cancellable — a Cancellable or None

set_exit_on_close¶

def set_exit_on_close(self, exit_on_close: bool) -> None

Sets whether the process should be terminated when connection is closed by the remote peer. See DBusConnection: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 with the session bus, and expect all of a user's 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.

Parameters:

exit_on_close — whether the process should be terminated when connection is closed by the remote peer

signal_subscribe¶

def signal_subscribe(self, sender: str | None, interface_name: str | None, member: str | None, object_path: str | None, arg0: str | None, flags: DBusSignalFlags | int, callback: DBusSignalCallback) -> int

Subscribes to signals on connection and invokes callback whenever the signal is received. Note that callback will be invoked in the thread-default main context (see GLib.MainContext.push_thread_default) of the thread you are calling this method from.

If connection is not a message bus connection, sender must be None.

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.

If one of DBusSignalFlags.MATCH_ARG0_NAMESPACE or DBusSignalFlags.MATCH_ARG0_PATH are given, arg0 is interpreted as part of a namespace or path. The first argument of a signal is matched against that part as specified by D-Bus.

If user_data_free_func is non-None, it will be called (in the thread-default main context of the thread you are calling this method from) at some point after user_data is no longer needed. (It is not guaranteed to be called synchronously when the signal is unsubscribed from, and may be called after connection has been destroyed.)

As callback is potentially invoked in a different thread from where it’s emitted, it’s possible for this to happen after DBusConnection.signal_unsubscribe has been called in another thread. Due to this, user_data should have a strong reference which is freed with user_data_free_func, rather than pointing to data whose lifecycle is tied to the signal subscription. For example, if a GObject.Object is used to store the subscription ID from DBusConnection.signal_subscribe, a strong reference to that GObject.Object must be passed to user_data, and GObject.Object.unref passed to user_data_free_func. You are responsible for breaking the resulting reference count cycle by explicitly unsubscribing from the signal when dropping the last external reference to the GObject.Object. Alternatively, a weak reference may be used.

It is guaranteed that if you unsubscribe from a signal using DBusConnection.signal_unsubscribe from the same thread which made the corresponding DBusConnection.signal_subscribe call, callback will not be invoked after DBusConnection.signal_unsubscribe returns.

The returned subscription identifier is an opaque value which is guaranteed to never be zero.

This function can never fail.

Parameters:

sender — sender name to match on (unique or well-known name) or None to listen from all senders
interface_name — D-Bus interface name to match on or None to match on all interfaces
member — D-Bus signal name to match on or None to match on all signals
object_path — object path to match on or None to match on all object paths
arg0 — contents of first string argument to match on or None to match on all kinds of arguments
flags — DBusSignalFlags describing how arg0 is used in subscribing to the signal
callback — callback to invoke when there is a signal matching the requested data

signal_unsubscribe¶

def signal_unsubscribe(self, subscription_id: int) -> None

Unsubscribes from signals.

Note that there may still be D-Bus traffic to process (relating to this signal subscription) in the current thread-default GLib.MainContext after this function has returned. You should continue to iterate the GLib.MainContext until the GDestroyNotify function passed to DBusConnection.signal_subscribe is called, in order to avoid memory leaks through callbacks queued on the GLib.MainContext after it’s stopped being iterated. Alternatively, any idle source with a priority lower than GLib.PRIORITY_DEFAULT that was scheduled after unsubscription, also indicates that all resources of this subscription are released.

Parameters:

subscription_id — a subscription id obtained from DBusConnection.signal_subscribe

start_message_processing¶

def start_message_processing(self) -> None

If connection was created with DBusConnectionFlags.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.

unexport_action_group¶

def unexport_action_group(self, export_id: int) -> None

Reverses the effect of a previous call to DBusConnection.export_action_group.

It is an error to call this function with an ID that wasn’t returned from DBusConnection.export_action_group or to call it with the same ID more than once.

Parameters:

export_id — the ID from DBusConnection.export_action_group

unexport_menu_model¶

def unexport_menu_model(self, export_id: int) -> None

Reverses the effect of a previous call to DBusConnection.export_menu_model.

It is an error to call this function with an ID that wasn't returned from DBusConnection.export_menu_model or to call it with the same ID more than once.

Parameters:

export_id — the ID from DBusConnection.export_menu_model

unregister_object¶

def unregister_object(self, registration_id: int) -> bool

Unregisters an object.

Parameters:

registration_id — a registration id obtained from DBusConnection.register_object

unregister_subtree¶

def unregister_subtree(self, registration_id: int) -> bool

Unregisters a subtree.

Parameters:

registration_id — a subtree registration id obtained from DBusConnection.register_subtree

Static functions¶

new¶

@staticmethod
def new(stream: IOStream, guid: str | None, flags: DBusConnectionFlags | int, observer: DBusAuthObserver | None = ..., cancellable: Cancellable | None = ..., callback: AsyncReadyCallback | None = ...) -> None

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

If stream is a SocketConnection, then the corresponding Socket 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 GObject.Object.unref on it.

If observer is not None it may be used to control the authentication process.

When the operation is finished, callback will be invoked. You can then call DBusConnection.new_finish to get the result of the operation.

This is an asynchronous failable constructor. See DBusConnection.new_sync for the synchronous version.

Parameters:

stream — a IOStream
guid — the GUID to use if authenticating as a server or None
flags — flags describing how to make the connection
observer — a DBusAuthObserver or None
cancellable — a Cancellable or None
callback — a GAsyncReadyCallback to call when the request is satisfied

new_for_address¶

@staticmethod
def new_for_address(address: str, flags: DBusConnectionFlags | int, observer: DBusAuthObserver | None = ..., cancellable: Cancellable | None = ..., callback: AsyncReadyCallback | None = ...) -> None

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 DBusConnection.new if you need to act as the server. In particular, flags cannot contain the DBusConnectionFlags.AUTHENTICATION_SERVER, DBusConnectionFlags.AUTHENTICATION_ALLOW_ANONYMOUS or DBusConnectionFlags.AUTHENTICATION_REQUIRE_SAME_USER flags.

When the operation is finished, callback will be invoked. You can then call DBusConnection.new_for_address_finish to get the result of the operation.

If observer is not None it may be used to control the authentication process.

This is an asynchronous failable constructor. See DBusConnection.new_for_address_sync for the synchronous version.

Parameters:

address — a D-Bus address
flags — flags describing how to make the connection
observer — a DBusAuthObserver or None
cancellable — a Cancellable or None
callback — a GAsyncReadyCallback to call when the request is satisfied

Properties¶

address¶

address: str  # read/write

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

authentication_observer¶

authentication_observer: DBusAuthObserver  # read/write

A DBusAuthObserver object to assist in the authentication process or None.

capabilities¶

capabilities: DBusCapabilityFlags | int  # read-only

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

closed¶

closed: bool  # read-only

A boolean specifying whether the connection has been closed.

exit_on_close¶

exit_on_close: bool  # 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 DBusConnection objects returned by bus_get_finish and bus_get_sync will (usually) have this property set to True.

flags¶

flags: DBusConnectionFlags | int  # read/write

Flags from the DBusConnectionFlags enumeration.

guid¶

guid: str  # read/write

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

If you are constructing a DBusConnection and pass DBusConnectionFlags.AUTHENTICATION_SERVER in the DBusConnection:flags property then you must also set this property to a valid guid.

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

Note that the D-Bus specification uses the term ‘UUID’ to refer to this, whereas GLib consistently uses the term ‘GUID’ for historical reasons.

Despite its name, the format of DBusConnection:guid does not follow RFC 4122 or the Microsoft GUID format.

stream¶

stream: IOStream  # read/write

The underlying IOStream used for I/O.

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

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

unique_name¶

unique_name: str  # read-only

The unique name as assigned by the message bus or None if the connection is not open or not a message bus connection.

Signals¶

closed¶

def on_closed(self, remote_peer_vanished: bool, error: GLib.Error | None) -> None: ...

Emitted when the connection is closed.

The cause of this event can be

If DBusConnection.close is called. In this case remote_peer_vanished is set to False and error is None.
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.