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=-1.0 required=5.0 tests=MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 6090 invoked from network); 12 Jun 2020 08:19:22 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 12 Jun 2020 08:19:22 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 242EF9C21A; Fri, 12 Jun 2020 18:19:17 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 7274C9C1C8; Fri, 12 Jun 2020 18:18:42 +1000 (AEST) Received: by minnie.tuhs.org (Postfix, from userid 112) id B48979C1C8; Fri, 12 Jun 2020 18:18:38 +1000 (AEST) Received: from viclamta27p.bpe.bigpond.com (viclamta27p.bpe.bigpond.com [203.38.21.91]) by minnie.tuhs.org (Postfix) with ESMTPS id 87263945D9 for ; Fri, 12 Jun 2020 18:18:37 +1000 (AEST) Received: from smtp.telstra.com ([10.10.26.4]) by viclafep27p-svc.bpe.nexus.telstra.com.au with ESMTP id <20200612081835.KMW1618.viclafep27p-svc.bpe.nexus.telstra.com.au@smtp.telstra.com> for ; Fri, 12 Jun 2020 18:18:35 +1000 X-RG-Spam: Unknown X-RazorGate-Vade: gggruggvucftvghtrhhoucdtuddrgeduhedrudeiuddgtdefucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuuffpveftpgfvgffnuffvtfetpdfqfgfvnecuuegrihhlohhuthemucegtddtnecunecujfgurhepfffhvffujgfkfhgfgggtsehmtddtredtreejnecuhfhrohhmpeffrghvvgcujfhorhhsfhgrlhhluceouggrvhgvsehhohhrshhfrghllhdrohhrgheqnecuggftrfgrthhtvghrnhepieegteeivdevfeffudekhfegleduveejkedtgfefudekhfekleelvdejheetfeefnecukfhppeduuddtrddugedurdduleefrddvfeefnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehhvghloheprghnvghurhhinhdrhhhorhhsfhgrlhhlrdhorhhgpdhinhgvthepuddutddrudeguddrudelfedrvdeffedpmhgrihhlfhhrohhmpeeouggrvhgvsehhohhrshhfrghllhdrohhrghequceuqfffjgepkeeukffvoffkoffgpdhrtghpthhtohepoehtuhhhshesthhuhhhsrdhorhhgqe X-RazorGate-Vade-Verdict: clean 0 X-RazorGate-Vade-Classification: clean X-RG-VS-CLASS: clean Received: from aneurin.horsfall.org (110.141.193.233) by smtp.telstra.com (5.8.420) id 5E8A564B0C2938F6 for tuhs@tuhs.org; Fri, 12 Jun 2020 18:18:34 +1000 Received: from aneurin.horsfall.org (localhost [127.0.0.1]) by aneurin.horsfall.org (8.15.2/8.15.2) with ESMTP id 05C8IWWl002228 for ; Fri, 12 Jun 2020 18:18:33 +1000 (EST) (envelope-from dave@horsfall.org) Received: from localhost (dave@localhost) by aneurin.horsfall.org (8.15.2/8.15.2/Submit) with ESMTP id 05C8IVlZ002225 for ; Fri, 12 Jun 2020 18:18:32 +1000 (EST) (envelope-from dave@horsfall.org) X-Authentication-Warning: aneurin.horsfall.org: dave owned process doing -bs Date: Fri, 12 Jun 2020 18:18:30 +1000 (EST) From: Dave Horsfall To: The Eunuchs Hysterical Society In-Reply-To: Message-ID: References: <20200601145801.GE22016@mcvoy.com> <20200604090436.GJ279@server.rulingia.com> <20200604165011.GC18437@mcvoy.com> User-Agent: Alpine 2.21.9999 (BSF 287 2018-06-16) X-GPG-Public-Key: http://www.horsfall.org/gpgkey.pub X-GPG-Fingerprint: 05B4 FFBC 0218 B438 66E0 587B EF46 7357 EF5E F58B X-Home-Page: http://www.horsfall.org/ X-Witty-Saying: "chmod 666 the_mode_of_the_beast" MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="1483753691-235702026-1591949912=:44790" 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" This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --1483753691-235702026-1591949912=:44790 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8BIT On Fri, 5 Jun 2020, Dan Cross wrote: > Was it Rob who said that signals were really just for SIGKILL? Here, > signals would be gang-pressed into service as a general IPC mechanism. > In fairness, they've mutated that way, but they didn't start out that > way. While I obviously wasn't there, the strong impression I get is that > by the time people were seriously thinking about async IO in Unix, the > die had already been cast for better or worse. I will quite happily strangle anyone who uses signals for IPC. Why? I got bitten quite badly by that, if anyone here remembers BSD/OS... It seemed that "fdump" forked off several kiddies, and they chatted amongst themselves using signals. Anyway, let's just say that after a disk crash this was a poor time to discover that *some* of my backups were screwed in a weird way; for example, there was a 1/4" QIC[*] tape with files, but no inodes to put them into their corresponding home directories... I wrote something to extract whatever I could, excavate what I could, and then either rebuild or rely upon memory from there. Not fun. Did I mention that I will quite happily strangle anyone who uses signals for IPC? Signals mean "stop what you're doing now, do this instead, then hopefully go back to whatever you thought you were doing". [*] Don't ask me about those !@#$% QIC tapes, that chose to use whatever density they wished depending upon the phase of the moon etc. -- Dave, who lost a lot of valuable files that day --1483753691-235702026-1591949912=:44790--