From: jnc@mercury.lcs.mit.edu (Noel Chiappa)
To: tuhs@minnie.tuhs.org
Cc: jnc@mercury.lcs.mit.edu
Subject: Re: [TUHS] non-blocking IO
Date: Mon, 1 Jun 2020 20:08:45 -0400 (EDT) [thread overview]
Message-ID: <20200602000845.CF26E18C073@mercury.lcs.mit.edu> (raw)
> when you're working below the reliable stream level, you can't just do a
> blocking 'read' for a packet; it pretty much has to be asynchronous
Oh, you should look at the early BBN TCP for V6 Unix - they would have faced
the same issue, with their TCP process. They did have the capac() call (which
kind of alleviates the need for non-blocking I/O), but that may have only been
available for ports/pipes; I'm not sure if the ARPANET device supported it.
(With the NCP as well, that did some amount of demultiplexing in the kernel,
and probably had buffering there, so, if so, in theory capac() could have been
done there. Of course, with the ARPANET link being only 100Kbit/sec maximum -
although only to a host on the same IMP - the overhead of copying buffered
data made kernel buffering more 'affordable'.)
Noel
next reply other threads:[~2020-06-02 0:09 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-02 0:08 Noel Chiappa [this message]
-- strict thread matches above, loose matches on Subject: below --
2020-06-06 13:29 Noel Chiappa
2020-06-02 20:13 Noel Chiappa
2020-06-02 20:43 ` Clem Cole
2020-06-02 22:14 ` Rich Morin
2020-06-03 16:31 ` Paul Winalski
2020-06-03 19:19 ` John P. Linderman
2020-06-02 14:19 Paul Ruizendaal
2020-06-02 17:45 ` Paul Winalski
2020-06-02 17:59 ` arnold
2020-06-02 18:53 ` Paul Winalski
2020-06-02 19:18 ` Clem Cole
2020-06-02 21:15 ` Lawrence Stewart
2020-06-02 18:23 ` Dan Cross
2020-06-02 18:56 ` Paul Winalski
2020-06-02 19:23 ` Clem Cole
2020-06-02 8:22 Paul Ruizendaal
2020-06-01 23:17 Noel Chiappa
2020-05-31 11:09 Paul Ruizendaal
2020-05-31 16:05 ` Clem Cole
2020-05-31 16:46 ` Warner Losh
2020-05-31 22:01 ` Rob Pike
2020-06-01 3:32 ` Dave Horsfall
2020-06-01 14:58 ` Larry McVoy
2020-06-04 9:04 ` Peter Jeremy
2020-06-04 14:19 ` Warner Losh
2020-06-04 16:34 ` Tony Finch
2020-06-04 16:50 ` Larry McVoy
2020-06-05 16:00 ` Dan Cross
2020-06-12 8:18 ` Dave Horsfall
2020-06-01 16:58 ` Heinz Lycklama
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