dns_dispatch_create() no longer exists. dns_dispatch_createtcp()
and dns_dispatch_getudp() are the replacements. _createtcp() takes
a bound, connected TCP socket, while _getudp() will search for
a sharable UDP socket, and if found, attach to it and return a
pointer to it. If one is not found, it will create a udp socket,
bind it to a supplied local address, and create a new dispatcher
around it.
dns_dispatch_remove{request,response}() no longer take the dispatch
as an argument.
query-source can now be set per view.
The dispatch manager holds onto three memory pools, one for
allocating dispatchers from, one for events, and one for
requests/replies. The free list on these pools is hard-coded,
but set to 1024. This keeps us from having to dig into the
isc_mem_t the pools draw from as often.
dns_resolver_create() and dns_view_createresolver() require that
valid dispatchers be passed in; dispatchers are no longer created
for the caller.