SD_BUS_ADD_OBJECT_MANAGER(3)

NAME
sd_bus_add_object_manager - Add a D-Bus object manager for a D-Bus object sub-tree

SYNOPSIS

#include <systemd/sd-bus.h>

int sd_bus_add_object_manager(sd_bus *bus, sd_bus_slot **slot, const char *path);

DESCRIPTION

sd_bus_add_object_manager() installs a handler for the given path that implements the GetManagedObjects() method of the org.freedesktop.DBus.ObjectManager interface. See org.freedesktop.DBus.ObjectManager[1] for more information.

To implement the InterfacesAdded and InterfacesRemoved signals of the org.freedesktop.DBus.ObjectManager interface, call sd_bus_emit_interfaces_added(3) and sd_bus_emit_interfaces_removed(3) whenever interfaces are added or removed from the sub-tree, respectively.

When sd_bus_add_object_manager() succeeds, a slot is created internally. If the output parameter slot is NULL, a "floating" slot object is created, see sd_bus_slot_set_floating(3). Otherwise, a pointer to the slot object is returned. In that case, the reference to the slot object should be dropped when the object manager is not needed anymore, see sd_bus_slot_unref(3).

RETURN VALUE

On success, sd_bus_add_object_manager() returns a non-negative integer. On failure, it returns a negative errno-style error code.

  Errors

Returned errors may indicate the following problems:

-EINVAL
    One of the required parameters is NULL or path is not a valid object path.

-ENOPKG
    The bus cannot be resolved.

-ECHILD
    The bus was created in a different process, library or module instance.

-ENOMEM
    Memory allocation failed.

NOTES

Functions described here are available as a shared library, which can be compiled against and linked to with the libsystemd pkg-config(1) file.

The code described here uses getenv(3), which is declared to be not multi-thread-safe. This means that the code calling the functions described here must not call setenv(3) from a parallel thread. It is recommended to only do calls to setenv() from an early phase of the program when no other threads have been started.

HISTORY

sd_bus_add_object_manager() was added in version 221.

SEE ALSO

sd-bus(3), busctl(1), sd_bus_add_object_vtable(3), sd_bus_emit_interfaces_added(3), sd_bus_slot_unref(3)

NOTES

1.  org.freedesktop.DBus.ObjectManager
    https://dbus.freedesktop.org/doc/dbus-specification.html#standard-interfaces-objectmanager