From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from seine.is.ed.ac.uk (seine.is.ed.ac.uk [129.215.17.202]) by sourceware.org (Postfix) with ESMTPS id 51DC3385803B for ; Wed, 10 Nov 2021 18:42:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 51DC3385803B Received: from crunchie.inf.ed.ac.uk (crunchie.inf.ed.ac.uk [129.215.202.41]) by seine.is.ed.ac.uk (8.14.7/8.14.7) with ESMTP id 1AAIgVew032616 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 10 Nov 2021 18:42:31 GMT Received: from ecclerig.inf.ed.ac.uk (ecclerig.inf.ed.ac.uk [129.215.24.151]) by crunchie.inf.ed.ac.uk (8.14.7/8.14.7) with ESMTP id 1AAIgUR6015104; Wed, 10 Nov 2021 18:42:30 GMT Received: by ecclerig.inf.ed.ac.uk (Postfix, from userid 27024) id 470F21202ED; Wed, 10 Nov 2021 18:42:31 +0000 (GMT) To: Ken Brown Cc: Subject: Re: Another pipe-related problem? References: <05c4180e-396b-4af3-ac0c-2ab8125df17e@cornell.edu> <0971ace1-5ee8-bdcc-5fd9-4551b294ebf8@cornell.edu> <75197fd0-d5da-3236-a7df-b8ffc3f67da7@cornell.edu> <4b937b32-e348-19d2-2406-c55fa12e20a3@cornell.edu> <83df50b8-5c0c-41b9-1e9e-4ea6bfa3d69f@cornell.edu> From: "Henry S. Thompson" Date: Wed, 10 Nov 2021 18:42:31 +0000 In-Reply-To: <83df50b8-5c0c-41b9-1e9e-4ea6bfa3d69f@cornell.edu> (Ken Brown's message of "Wed\, 10 Nov 2021 13\:03\:09 -0500") Message-ID: User-Agent: Gnus/5.101 (Gnus v5.10.10) XEmacs/21.5-b34 (linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Edinburgh-Scanned: at seine.is.ed.ac.uk X-Spam-Status: No, score=-2.2 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: cygwin@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: General Cygwin discussions and problem reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Nov 2021 18:42:42 -0000 Ken Brown writes: > ... > The main change was that we stopped using Win32 Overlapped I/O > (https://docs.microsoft.com/en-us/windows/win32/sync/synchronization-and-overlapped-input-and-output) > and switched to using the NT API. As a result, pipe I/O became much > more efficient. It wouldn't surprise me if the efficiency alone is > what exposed the bug. > > The good news is that the bug doesn't seem to occur in XEmacs 21.4 > (on 32-bit Cygwin). So one way to approach this would be to bisect > the XEmacs git repo to find the commit that introduced the bug. > You'd probably have to do the work on 32-bit Cygwin since, if I > remember correctly, XEmacs 21.4 didn't build on 64-bit Cygwin. Right, although I _suspect_ it will be in 64-bit-only code. Easy enough to find out, once I resurrect a 32-bit install on a spare machine that I can run 3.3 on (I use XEmacs all day every day from my day job, so I need to stay with 3.2 until we fix this). So, this may take a while, unless someone else hits the problem and finds a simpler test case. Thanks again, ht -- Henry S. Thompson, School of Informatics, University of Edinburgh 10 Crichton Street, Edinburgh EH8 9AB, SCOTLAND -- (44) 131 650-4440 Fax: (44) 131 650-4587, e-mail: ht@inf.ed.ac.uk URL: http://www.ltg.ed.ac.uk/~ht/ [mail from me _always_ has a .sig like this -- mail without it is forged spam] The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.