From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 23398 invoked from network); 2 Jun 2020 09:35:37 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 2 Jun 2020 09:35:37 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 884AE9C92B; Tue, 2 Jun 2020 19:35:34 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 031789C5F8; Tue, 2 Jun 2020 19:35:02 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (1024-bit key; unprotected) header.d=planet.nl header.i=@planet.nl header.b="RW8gcQd6"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 1BA389C5F8; Tue, 2 Jun 2020 19:35:00 +1000 (AEST) Received: from cpsmtpb-ews08.kpnxchange.com (cpsmtpb-ews08.kpnxchange.com [213.75.39.13]) by minnie.tuhs.org (Postfix) with ESMTP id 1724893D46 for ; Tue, 2 Jun 2020 19:34:57 +1000 (AEST) Received: from cpsps-ews26.kpnxchange.com ([10.94.84.192]) by cpsmtpb-ews08.kpnxchange.com with Microsoft SMTPSVC(8.5.9600.16384); Tue, 2 Jun 2020 11:34:54 +0200 X-Brand: 7abm2Q== X-KPN-SpamVerdict: e1=0;e2=0;e3=0;e4=(e1=10;e3=10;e2=11;e4=10);EVW:Whi te;BM:NotScanned;FinalVerdict:Clean X-CMAE-Analysis: v=2.3 cv=O/OiQC1W c=1 sm=1 tr=0 cx=a_idp_e a=aIJzBKXFL4aO3PtWP49Erg==:117 a=soxbC+bCkqwFbqeW/W/r+Q==:17 a=x1i13A_MHe4A:10 a=IkcTkHD0fZMA:10 a=nTHF0DUjJn0A:10 a=AoeSMSUmAAAA:8 a=xN30SpXcdmJKmJDRH5UA:9 a=QEXdDO2ut3YA:10 a=2UY7SMgi64q-0UtCmZ5F:22 X-CM-AcctID: kpn@feedback.cloudmark.com Received: from smtp.kpnmail.nl ([195.121.84.43]) by cpsps-ews26.kpnxchange.com over TLS secured channel with Microsoft SMTPSVC(8.5.9600.16384); Tue, 2 Jun 2020 11:34:54 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=planet.nl; s=planet01; h=to:date:message-id:subject:mime-version:content-type:from; bh=R27BfSD72bw2d07VRoCKqa7vpFMDvsWwfUwflz7s/IY=; b=RW8gcQd6iBi9SxaeYrEubDO8EVP2WsOMDfNNZA8MGXRszw4onmStKsspHTDxn526AgS/PZC7MelZ3 stlyOn6FtQdLM72je8UuKBjIsPnmCi32iPdXmHVGwhJuByKZnXQ12S77vLuqbScAaJYj14vtMARPVJ NL4+tX8Eo1hNtDaQ= X-KPN-VerifiedSender: Yes X-CMASSUN: 33|wVPIJsgWO9qKHc1UOSJ5OU4NErT/UTH0uTroagsan21mHPbJIENLGHqZl9lvUfS ebw+Sf2tWjAUAIGdB5TCv6w== X-Originating-IP: 80.101.112.122 Received: from mba2.fritz.box (sqlite.xs4all.nl [80.101.112.122]) by smtp.kpnmail.nl (Halon) with ESMTPSA id 50b25789-a4b4-11ea-93ae-005056ab1411; Tue, 02 Jun 2020 11:34:55 +0200 (CEST) From: Paul Ruizendaal Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.11\)) Message-Id: Date: Tue, 2 Jun 2020 11:34:54 +0200 To: TUHS main list X-Mailer: Apple Mail (2.3445.104.11) X-OriginalArrivalTime: 02 Jun 2020 09:34:54.0907 (UTC) FILETIME=[12C9D8B0:01D638C1] X-RcptDomain: minnie.tuhs.org Subject: [TUHS] non-blocking IO (morphing to "The serial I/O loop") X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" > On 5/31/2020 9:46 AM, Warner Losh wrote: > > Sorry to top post, but LSX or Miniunix had non blocking I/O as well.=20= > > It was in one of the documents that Clem scanned in the last year. = It=20 > > specifically was an experiment into how to do it. > > > > Warner > I did add a few new features to LSX to deal with contiguous files > and to handle asynchronous read/write's for real time applications. > They are described in the LSX paper in the 1978 BSTJ on the > UNIX Time-Sharing System. >=20 > Heinz Thanks for highlighting this! The realm here is async I/O to disk, my original scope was limited to = =E2=80=9Ccommunication=E2=80=9D files (tty=E2=80=99s, pipes, network = connections). Still, I find it an interesting topic. For others, the paper that you refer to can also be found here: = https://www.tuhs.org/Archive/Documentation/TechReports/Heinz_Tech_Memos/UN= IX_on_a_Microprocessor_19780322.pdf If I read correctly, the async functionality was available only in the = stand alone program version of LSX. Is that correct? In any case, the = source code appears lost. =46rom another paper in that set, I get the impression that the async = functionality for LSX builds on earlier work for a very early version of = Unix: = https://www.tuhs.org/Archive/Documentation/TechReports/Heinz_Tech_Memos/TM= -74-1352-1_Implementation_of_Large_Contiguous_Files_and_Asynchronous_IO_in= _UNIX_19740104.pdf - - - When reading through the papers in that TUHS directory, something else = caught my attention: early networking at the labs. For a while I have = been puzzled by the =E2=80=9Cserial I/O loop=E2=80=9D in use at the labs = in the early seventies. Last Fall I found some 1970/1971 BSTJ papers = about it, but there it stopped. I see in the memo on Glance = (https://www.tuhs.org/Archive/Documentation/TechReports/Heinz_Tech_Memos/T= M-75-1352-3_GLANCE_Terminals_on_UNIX_Time-Sharing_19750303.pdf) that = D.R. Weller continued to work on it up to 1973 at least and that it was = integrated with Unix in some way. Is that correct? Did the two memo=E2=80=99= s referred to (MM 70-1384-1 and TM 73-1356-8) survive? Then the memo on satellite processors is very interesting = (https://www.tuhs.org/Archive/Documentation/TechReports/Heinz_Tech_Memos/T= M-78-3114-2_A_Minicomputer_Satellite_Processor_System_19780322.pdf). = This appears to show the serial I/O loop in use as late as 1978, with a = very intriguing use case involving system call forwarding over the = network. Can you tell me more about the serial I/O loop and its use cases?