r21064: The core of this patch is

r21064: The core of this patch is

 void message_register(int msg_type,
                      void (*fn)(int msg_type, struct process_id pid,
-                                void *buf, size_t len))
+                                void *buf, size_t len,
+                                void *private_data),
+                     void *private_data)
 {
        struct dispatch_fns *dfn;

So this adds a (so far unused) private pointer that is passed from
message_register to the message handler. A prerequisite to implement a tiny
samba4-API compatible wrapper around our messaging system. That itself is
necessary for the Samba4 notify system.

Yes, I know, I could import the whole Samba4 messaging system, but I want to
do it step by step and I think getting notify in is more important in this
step.

Volker
(This used to be commit c8ae60ed65dcce9660ee39c75488f2838cf9a28b)