fostel@ncsu.UUCP (09/20/83)
Someone suggested a way to extend pipes to serve as a better IPC system,
by attaching filesystem names .. etc. Someone else responded that Berkley
had done just that and the result was sockets. Well, the history is very
long on this item and Berkley is far from the first (or likely the last)
word on the subject. The oldest reference I have is a paper by Carl
Sunshine at Rand, circa early 70's. The name chosen then was "port",
a much nicer one than "socket" except for the popularity of sockets in
networking jargon. A port was just what you might expect. To allow an
interrupt like system (essential for the server systems such IPC is often
used for) a new system call was added, the "await" call, which allowed
you to go to sleep until there was activity on the port. Also a "capac"
call to allow polling on the availability of data as an alternative to
await.
Similar though I think not quite as nice was Berkleys MPX files, Bells
Fifi files and a host of varioations on the original Rand model.
Decendents of the Port model are still in use, e.g NBS networking modeling.
(sorry Fif-o- files.) I have not yet seen a good description of BSD4.2
so I don't know if berkley has advanced the state of the art or just
re-written it. <- last time someone confessed ignorance of 4.2, there was
a rather snide remark about all the ways of learning about it and the
lack of weight behind an opinion from such a person. I have learned that
you can never tell whether a UNIX anything is good until you try to use
it, since the written descriptions tend to be _______ (supply your favorite
word) ->
----GaryFostel----