[bind10-dev] fd_share / send_fd

[Francis Dupont]

Some questions about fd_share / send_fd:
 - it seems there are two versions of them today: src/lib/xfr and
  src/lib/util/io. It seems it is a simple code reorg, i.e.,
  the code moved from xfr to util/io (BTW this is a good idea)

 - what kind of descriptors are moved? on some systems file
  descriptors and "socket" file descriptors are different
  (cf. Windows file and socket handles, note both can be
   sent to another process and they are more different than
   one could believe, e.g., close functions are different too!)
  (it seems sockets, cf xfr code)

 - there are other ways to send a file descriptor, for instance
  one can open /proc/<other_process_id>/fd/<file_descriptor_number>
  on Linux or in general any OS with /proc file system.
  I'd like to get a fd_share / send_fd clone using this /proc way
  (IMHO it is far closer than PF_UNIX to what Windows support,
   and this can remove some dependencies too).

Thanks

Francis Dupont <fdupont at isc.org>