|Launchd[1,2] replaces init, inetd and cron on Mac OS X since 10.4 "Tiger".
|dbus uses this service to provide a common session bus address for each user
|and so deprecates the X11 enabled dbus-launcher.
|Configure with --enable-launchd and --without-x (X11 should not harm but it's
|simply not necessary any more)
|After installation, to prevent a reboot, load the dbus session starter into
|launchd by executing:
|$ launchctl load /Library/LaunchAgents/org.freedesktop.dbus-session.plist
|You can change the launch agent dir via configure, but it's not recommended.
|Make sure to execute the above line as the actual user for which you want to
|use a session bus since launchd manages its agents on a per user basis.
|How it works
|Launchd allocates a socket and provides the unix path to it via the variable
|DBUS_LAUNCHD_SESSION_BUS_SOCKET in launchd's environment. Every process
|spawned by launchd (or dbus-daemon, if stared by launchd) can access it through
|its own environment. Other processes can query launchd for it by executing:
|$ launchctl getenv DBUS_LAUNCHD_SESSION_BUS_SOCKET
|However, this is normally done by the dbus client lib for you.
|If launchd start dbus-daemon with a config file containing a "launchd:env=FOO"
|address, as the default session config does with env=DBUS_LAUNCHD_SESSION_BUS_SOCKET,
|the daemon will get the file descriptor from launchd and start listening on it.
|The environment variable is used to get the actual socket path which is passed
|to every service spawned by dbus-daemon as a result from autolaunch messages.
|Please note that it's not possible to start dbus-daemon manually when using a
|"launchd:" address. Only child processes of launchd can access the above
|mentioned file descriptor!
|To create custom buses just set up an other launch agent. As a quick start copy
|/Library/LaunchAgents/org.freedesktop.dbus-session.plist, change the label
|to i.e. "org.freedesktop.dbus-foo" and change the SecureSocketWithKey value,
|i.e. to "DBUS_LAUNCHD_FOO_BUS_SOCKET". This environment variable has to be set
|in the config file for your new bus in the <listen> element (see session.config).
|Then edit your /Library/LaunchAgents/org.freedesktop.dbus-foo.plist to start
|dbus-daemon with "--config-file=/opt/local/etc/dbus-1/foo.conf" instead of
|"--session". Now load the new plist onto launchd as described in the setup
|section of this document.
|Executing "launchctl export" should now give you two sockets, one in
|DBUS_LAUNCHD_SESSION_BUS_SOCKET and the new DBUS_LAUNCHD_FOO_BUS_SOCKET.
|To connect to this new bus use "launchd:env=DBUS_LAUNCHD_FOO_BUS_SOCKET".
|Since Mac OS X 10.5 "Leopard" you can also configure launchd to start
|dbus-daemon on demand as soon as some process connects to the socket. Since
|it's broken on 10.4 this feature is disabled per default. Look at
|/Library/LaunchAgents/org.freedesktop.dbus-session.plist to change it.
|On the client side, the envvar DBUS_SESSION_BUS_ADDRESS can be normally used
|but if it's not set, launchd is queried for the session bus socket.