The ->init() callback of the connection's data layer was only used to
complete the session's initialisation since sessions and streams were
split apart in 1.6. The problem is that it creates a big confusion in
the layers' roles as the session has to register a dummy data layer
when waiting for a handshake to complete, then hand it off to the
stream which will replace it.
The real need is to notify that the transport has finished initializing.
This should enable a better splitting between these layers.
This patch thus introduces a connection-specific callback called
xprt_done_cb() which informs about handshake successes or failures. With
this, data->init() can disappear, CO_FL_INIT_DATA as well, and we don't
need to register a dummy data->wake() callback to be notified of errors.
Very early in the connection rework process leading to v1.5-dev12, commit
56a77e5 ("MEDIUM: connection: complete the polling cleanups") marked the
end of use for this flag which since was never set anymore, but it continues
to be tested. Let's kill it now.
The goal is to have a collection of quick-n-dirty utilities that make
debugging easier and that can easily be modified when needed. The first
utility in this series is called "flags". For a given numeric argument,
it reports the various known combinations of flags for channels, streams
and so on. This way it's easy to copy-paste values from the CLI or from
gdb and immediately know what state a stream-interface or connection is
in.
