6 Apr
2018
6 Apr
'18
6:03 p.m.
Sorry autocorrect bit me. And being discussed by both faculty and grad students a like
Sent from my PDP-7 Running UNIX V0 expect things to be almost but not quite.
On Apr 6, 2018, at 7:34 AM, Paul Ruizendaal
<pnr(a)planet.nl> wrote:
Date: Fri, 30 Mar 2018 00:28:13 -0400
From: Clem cole <clemc(a)ccc.com>
Also, joy / BSD 4.2 was heavily influenced by Accent (and RIG )and the Mach memory system
would eventually go back into BSD (4.3 IIRC) - which we have talked about before wrt to
sockets and Accent/Mach’s port concept.
From an "outsider looking in” perspective I’m not sure I recognise such heavy
influence in the sockets code base. Of course, suitability for distributed systems was an
important part of the 4.2BSD design brief and Rick Rashid was one of the steering
committee members, that is all agreed.
However in the code evolution for sockets I only see two influences that seem not direct
continuations from earlier arpanet unices and have a possible Accent origins:
- Addition of sendto()/recvfrom() to the API. Earlier code had poor support for UDP and
was forced through the TCP focused API’s, with fixed endpoint addresses. It could be
Accent inspired, it could also be a natural solution for sending datagrams. For example,
Jack Haverty had hacked a “raw datagram” facility into UoI Arpanet Unix around ’79 (it’s
in the Unix Tree).
- Addition of a facility to pass file descriptors using sendmsg()/recvmsg() in the local
domain. This facility was only added at the very last moment (it was not in 4.1c, only in
4.2). I’m being told that the CSRG team procrastinated on this because they did not see
much use for it — and indeed it was mostly ignored in the field for the next two decades.
Joy had left by that time, so perhaps the dynamics had changed.
Earlier I though that the select() call may have come from Accent, but it was inspired by
the Ada select statement. Conceptually, it was preceded on Unix by Haverty’s await() call
(also ’79).
For clarity: I wasn’t there, just commenting on what I see in the code.
Paul