From owner-freebsd-gnome@FreeBSD.ORG Tue Nov 9 05:54:35 2010 Return-Path: Delivered-To: gnome@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6722E106564A; Tue, 9 Nov 2010 05:54:35 +0000 (UTC) (envelope-from avg@freebsd.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 3E1998FC12; Tue, 9 Nov 2010 05:54:33 +0000 (UTC) Received: from porto.topspin.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id HAA14471; Tue, 09 Nov 2010 07:54:32 +0200 (EET) (envelope-from avg@freebsd.org) Received: from localhost.topspin.kiev.ua ([127.0.0.1]) by porto.topspin.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1PFhA8-00075T-GS; Tue, 09 Nov 2010 07:54:32 +0200 Message-ID: <4CD8E218.1030600@freebsd.org> Date: Tue, 09 Nov 2010 07:54:32 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.12) Gecko/20101029 Lightning/1.0b2 Thunderbird/3.1.6 MIME-Version: 1.0 To: Joe Marcus Clarke References: <20101109001442.F27651CC0E@ptavv.es.net> <4CD8DDCD.3010902@freebsd.org> <4CD8E075.9090901@freebsd.org> <4CD8E1B0.4010005@freebsd.org> In-Reply-To: <4CD8E1B0.4010005@freebsd.org> X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: gnome@freebsd.org, bug-followup@freebsd.org Subject: Re: ports/151725: sysutils/hal: hald fails to start with dbus-1.4 X-BeenThere: freebsd-gnome@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GNOME for FreeBSD -- porting and maintaining List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Nov 2010 05:54:35 -0000 on 09/11/2010 07:52 Andriy Gapon said the following: > on 09/11/2010 07:47 Joe Marcus Clarke said the following: >> On 11/9/10 12:36 AM, Andriy Gapon wrote: >>> on 09/11/2010 02:14 Kevin Oberman said the following: >>>> I'll try this as soon as I can. I'm not too sure that it will happen as >>>> I think that this is somehow timing related. I suspect that the entry is >>>> disappearing too quickly with 1.4 in some cases but is not a problem >>>> with 1.2. Perhaps some optimization? >>>> >>>> I suggest this because on at least rare occasion, 1.4 did run >>>> successfully, not because I have any clue what was happening under the >>>> covers. >>> >>> I guess that I already explained this part. >>> The problem happened because we tried to write something (even if it's just zero >>> sized something) into stdin of a child process that already exited. >>> Sometimes the child process was quicker, sometimes the parent process was >>> quicker, hence the non-determinism. >>> >> >> Ah, I missed that. I wonder if it would be safer then to ignore SIGPIPE >> around the write block. > > Maybe. Actually, please read the above as "probably no". If a child process that is supposed to get input would crash, then such a change would obfuscate diagnostics. > But not calling write(2) when we don't have anything to write (zero > length) also looks like a good solution (for me personally). > > My point is: zero-sized write in nothing but testing OS implementation details > of handling zero-sized writes, it doesn't perform any useful function. > OTOH, if a child process is supposed to get any actual input, then it won't exit > prematurely, but would block reading from its stdin until the input arrives. > > But I think I am starting to repeat what I have already wrote before. > -- Andriy Gapon