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,FREEMAIL_FROM,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 8792 invoked from network); 2 Jun 2020 17:46:32 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 2 Jun 2020 17:46:32 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 7344A9CAFB; Wed, 3 Jun 2020 03:46:23 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 09F8B9CAD4; Wed, 3 Jun 2020 03:46:00 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="tHXZTMii"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id BA88D9CAD2; Wed, 3 Jun 2020 03:45:57 +1000 (AEST) Received: from mail-vs1-f53.google.com (mail-vs1-f53.google.com [209.85.217.53]) by minnie.tuhs.org (Postfix) with ESMTPS id 545F49C96B for ; Wed, 3 Jun 2020 03:45:57 +1000 (AEST) Received: by mail-vs1-f53.google.com with SMTP id k3so2549359vsg.2 for ; Tue, 02 Jun 2020 10:45:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=yw/XJ04fg0vRba2wRvYaW7PXxV8Nnx361ieOLdXrN6o=; b=tHXZTMiiFyjgYzcq5FroZFRc1bY5jPhkle97TrrvbWXCQSTW4v273g9ENOYvqxFE5G zAy2xT9rsO5GtPt19gxldQuLkYP+L/sOIdIMyaUmsXD11Ity7NZF+7XtLaAZX3eqHM4Z dYutCWVIqMlDgRfl30lS4ute06tiQjJsBQL5mWwrbI+D7jUD3wRMi/xa3cnUcl+kjMNf DlZiYC4RZCvtRIKQawgYb28NhFmaNZa4ANBKHqsCgYJkIf83RupVsd0nEjxrJm4OOq+O iukPsJogscjSc5IRnbF77KmJ2BVnNQxZGW/CEz3MFeHV6UA/jJZtSlU/QfAe2I0dtI6h Fsig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=yw/XJ04fg0vRba2wRvYaW7PXxV8Nnx361ieOLdXrN6o=; b=aKhurA0+n9MLBBD6zALuyh9wTIOmqUqJMQS6DGb5+J/lWK9zppWV+bpvFCYcE+2Ps+ 4n6CJLDeSkS9iIhvaFkJaehBv9mxlrsaiREZEIrGtG9S1eWPLZZ+Oc858gkTSEJ/MnRr /7kcOSIUTNH3f8bLqpKVtN/wKbcfWWjXU0KMYwl/2FTm9pKl64LJzgalsfpLndVGi7ld QKdpPczw2OLptUtqbyE4itRMpkP5MrDIpmHbrprpfid1Fj7t/EpLMjuhnQUpvu/j62ao sVUEQj3WppH/NDssTUnCCmOc2n/1mXaC2pY0mZ3bjQNzgPCwkW6jiBNFWRau03PQv3e7 YY5w== X-Gm-Message-State: AOAM531n/tRBJr365YDlXgheZBNDMUExj1NcSSf2ACCbTZaA3vbjBrF6 XB8yXy1DMKg72AxCCBxgTUfPSzJTPRnrKtAOnNRaqw== X-Google-Smtp-Source: ABdhPJwvcleKo9LvqHJqUfUUyCfKH05/bai6qpwHkFajxZk8Z71xRxmuitaos38yP3QuLz0gKvfxMnrHHxvDge1fDTM= X-Received: by 2002:a67:22c7:: with SMTP id i190mr4938700vsi.179.1591119955875; Tue, 02 Jun 2020 10:45:55 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:ab0:2b92:0:0:0:0:0 with HTTP; Tue, 2 Jun 2020 10:45:55 -0700 (PDT) In-Reply-To: References: From: Paul Winalski Date: Tue, 2 Jun 2020 13:45:55 -0400 Message-ID: To: TUHS main list Content-Type: text/plain; charset="UTF-8" Subject: Re: [TUHS] non-blocking IO 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" The operating systems that I cut my teeth on (OS/360, DOS/360, VAX/VMS) all had basic I/O system calls that were non-blocking. Blocking I/O calls were all built on top of that framework. I thus found it curious that Unix took the opposite tack, and non-blocking I/O was an afterthought. So I'm curious as to what the rationale was for Unix to have been designed with basic I/O being blocking rather than asynchronous. Especially that non-blocking I/O primitives were the norm for OSes in those days. -Paul W.