From owner-freebsd-hackers@freebsd.org Sun Feb 10 23:20:37 2019 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7AD8814E0D19 for ; Sun, 10 Feb 2019 23:20:37 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: from mail-it1-f177.google.com (mail-it1-f177.google.com [209.85.166.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id B39B47129B for ; Sun, 10 Feb 2019 23:20:36 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: by mail-it1-f177.google.com with SMTP id h193so21910643ita.5 for ; Sun, 10 Feb 2019 15:20:36 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc; bh=lq9aPUmJMhL/9logtrGxZH4a+3t0WDmv34ZSnPR2/HI=; b=exmv803o7oSyvsmEiR/RqfpmNfbsA9nDLHa/toxnOOIgf/hyvK9xrQrcRxLgmtYvgm h1JcodXz3cyhYU74O+xQ14jFBpdgcWSre/N72SvMFUQHGrE/yi7YTLtfGOHRc7Mbzi3+ 7KZ/Rn7Hf6zXrrVeLYl9aBumERxbK+1jzZ0/1hjce1uvFn/+gQeb9VFCGdVhjtpMaw0/ f6w4BFQK+Q3CuMq2gczps2BxJS7mihXbNN1liNWmeYZZRo75H4kRs8TrHDpsOa4a7GsF HE0A8KgyoNGJRpFrRrg+8fVR0ne7gT1Zs/UZkjChh+W/1kNINnarf3QoYzN7SVzmVpIz Ff0w== X-Gm-Message-State: AHQUAuY9jDUL5MdNc2KhpJx+YPbiMnpLJ7LBJd1pxNwLeEa4nWlBRNiY 4v8qkpznNb/c/vrd+DSXcFTcbsAL X-Google-Smtp-Source: AHgI3IaN2KPKo0oj5U/G5cy4+uJEAo5zdUXAaG1mcA2rAo8IjAmjD53AIJwHu/y4LUQt34SoR8XvVg== X-Received: by 2002:a02:1c41:: with SMTP id c62mr16013996jac.109.1549840829666; Sun, 10 Feb 2019 15:20:29 -0800 (PST) Received: from mail-it1-f175.google.com (mail-it1-f175.google.com. [209.85.166.175]) by smtp.gmail.com with ESMTPSA id y10sm3963710iom.9.2019.02.10.15.20.29 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 10 Feb 2019 15:20:29 -0800 (PST) Received: by mail-it1-f175.google.com with SMTP id a6so21919899itl.4 for ; Sun, 10 Feb 2019 15:20:29 -0800 (PST) X-Received: by 2002:a24:b64a:: with SMTP id d10mr4416415itj.149.1549840829158; Sun, 10 Feb 2019 15:20:29 -0800 (PST) MIME-Version: 1.0 References: <201902100136.x1A1aXXv039736@slippy.cwsent.com> <201902100420.x1A4KSxA064573@pdx.rh.CN85.dnsmgr.net> In-Reply-To: <201902100420.x1A4KSxA064573@pdx.rh.CN85.dnsmgr.net> Reply-To: cem@freebsd.org From: Conrad Meyer Date: Sun, 10 Feb 2019 15:20:18 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: nosh init system To: "Rodney W. Grimes" Cc: "freebsd-hackers@freebsd.org" Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: B39B47129B X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of csecem@gmail.com designates 209.85.166.177 as permitted sender) smtp.mailfrom=csecem@gmail.com X-Spamd-Result: default: False [-5.80 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; HAS_REPLYTO(0.00)[cem@freebsd.org]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; REPLYTO_ADDR_EQ_FROM(0.00)[]; RCVD_COUNT_THREE(0.00)[4]; MX_GOOD(-0.01)[cached: alt3.gmail-smtp-in.l.google.com]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_SHORT(-0.83)[-0.826,0]; FORGED_SENDER(0.30)[cem@freebsd.org,csecem@gmail.com]; IP_SCORE(-2.96)[ip: (-9.01), ipnet: 209.85.128.0/17(-3.77), asn: 15169(-1.95), country: US(-0.07)]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; FROM_NEQ_ENVFROM(0.00)[cem@freebsd.org,csecem@gmail.com]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; TAGGED_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-hackers@freebsd.org]; DMARC_NA(0.00)[freebsd.org]; MIME_TRACE(0.00)[0:+]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[177.166.85.209.list.dnswl.org : 127.0.5.0]; RCVD_TLS_LAST(0.00)[] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 10 Feb 2019 23:20:37 -0000 On Sat, Feb 9, 2019 at 8:20 PM Rodney W. Grimes wrote: > It -should- be safe to restart rc, as rc scripts should check to > see if the item they are being requested to start is already running, It isn't, as described in detail in the email Cy replied to. There is some difficulty in making scripts idempotent even in relatively happy cases; not everything has a pid file (and pid files are not a particularly robust system anyway). Even harder are weird corner cases like interrupted and resumed boot, that are rarely or never tested. Shell is just a poor language for any sophisticated behavior or robust error handling. Conrad