SD_BUS_AD...CT_MANAGER(3)

👑 NAME 👑

okay so bestie, this page is all about sd_bus_add_object_manager — and yes that's the manual name, it lives in section 3 of the systemd manual, and it's literally the function that adds a D-Bus object manager for a D-Bus object sub-tree. no cap. 💅

✨ SYNOPSIS ✨

#include <systemd/sd-bus.h>

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

💖 DESCRIPTION 💖

So sd_bus_add_object_manager() installs a handler for the given path that implements the GetManagedObjects() method of the org.freedesktop.DBus.ObjectManager interface. that's the whole vibe. see org.freedesktop.DBus.ObjectManager[1] for more info if you wanna deep-dive. 🦋

Now, to implement the InterfacesAdded and InterfacesRemoved signals of that same org.freedesktop.DBus.ObjectManager interface, you gotta 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. like, that's the move. periodt. 🌸

When sd_bus_add_object_manager() succeeds, a slot is created internally — main character energy. 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). don't leave that reference hanging, bestie, that's not the vibe. 🙈

🎀 RETURN VALUE 🎀

On success, sd_bus_add_object_manager() returns a non-negative integer. slay. ✨ On failure, it returns a negative errno-style error code. and that's the tea. 💀

🌈 Errors 🌈

Returned errors may indicate the following problems — keep these in your notes fr fr:

• -EINVAL — one of the required parameters is NULL or path is not a valid object path. not the vibe. 🚫
• -ENOPKG — the bus cannot be resolved. like it's giving "who dis?" 😭
• -ECHILD — the bus was created in a different process, library or module instance. awkward. 🙈
• -ENOMEM — memory allocation failed. the audacity of this economy. 💀

💜 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. icon behavior. 👑

All functions listed here are thread-agnostic and only a single thread may operate on a given object at any given time. Different threads may access the same object at different times. Multiple independent objects may be used from different threads in parallel. so like, don't be messy with your threads, okay? one at a time per object, but different objects can vibe in parallel. 🧚

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. so like, do your setenv() before the party starts, not during. highkey important. 💅

⭐ HISTORY ⭐

sd_bus_add_object_manager() was added in version 221. a classic. 🎀

🦋 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 (the footnote era) 📝

1. org.freedesktop.DBus.ObjectManager — [https://dbus.freedesktop.org/doc/dbus-specification.html#standard-interfaces-objectmanager](https://dbus.freedesktop.org/doc/dbus-specification.html#standard-interfaces-objectmanager)

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okay that's the whole page, bestie. this was systemd 261.3, and you understood it because you're literally so smart. no cap. 💖✨🎀🦋🌸💅🫶😭🔥👑🌈⭐💀🙈🍓🧚💜