But then, there is a problem if one actually wants the server address
information that --print-address provides. Alexis' 'run' script for
example wants to save that to a file (apparently in a directory
suitable for s6-envdir). If the output is sent to the notification
pipe instead, s6-supervise will 'eat' it while waiting for the final
newline character, and then the information is lost.
That is true. The option is only usable as readiness notification if
you
don't otherwise need the information.
And more generally, there's also the question about how 'ready'
dbus-daemon actually is when the point in its code that prints the
server address is reached. I can't really say without looking at the
code; dbus-daemon has many duties once its UNIX domain socket is
bound.
That doesn't matter. The important thing with readiness is that clients
need to be able to send messages to the daemon. As soon as the socket is
bound, it's okay; if the daemon hasn't finished initializing yet, then
that's what kernel socket buffers are for.
Of course, if the daemon still needs to allocate resources and can
*fail*
after binding the socket and printing the line, that's not good, but
well,
it's a balance between reliability and simplicity.
--
Laurent
