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To: cygwin@cygwin.com References: <71490665-31b0-f63c-74da-461a053fac21@huarp.harvard.edu> From: Ken Brown Message-ID: <55ea1649-1979-6238-75ab-69100c22e069@cornell.edu> Date: Wed, 25 Nov 2020 17:27:22 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 In-Reply-To: <71490665-31b0-f63c-74da-461a053fac21@huarp.harvard.edu> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [68.175.129.7] X-ClientProxiedBy: MN2PR05CA0058.namprd05.prod.outlook.com (2603:10b6:208:236::27) To MN2PR04MB6176.namprd04.prod.outlook.com (2603:10b6:208:e3::13) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [192.168.0.17] (68.175.129.7) by MN2PR05CA0058.namprd05.prod.outlook.com (2603:10b6:208:236::27) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.3632.6 via Frontend Transport; Wed, 25 Nov 2020 22:27:22 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 00110581-13f8-452a-314c-08d891914790 X-MS-TrafficTypeDiagnostic: MN2PR04MB5967: X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:10000; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: EGdk4g3eDGUwI2JrN0gVjDl2pDrdL76FXiXYYBjuzT9NYp8Syxi1Jt7n3wl8ECbRmlSVHZY79zWrc1SEYONrCwaqvKbyqWZkwrKlY2igxQr9/Vt9lyFcmAo1eXri+LBGOcPsQwoX1aez0I9Q7i7GIv21GdStqEAwAjurfRm9QAVV1o+ydDfFQ2s6vpchrW4FD/bByDrFYxyeq9IcftN64foztfc0/VukMHkFV2lcUvGVmZiKn7O5rTqrrIS/DnMZ+GkoCsKdXblqNX+4NJ7daFLbr3ArmzjKgSpaQd+LzWKAFL/23yVvIAycIer3J/pROJz4OtDAGMrcNV9tCExdGvF7yi6Bxy3NScUeRfqfMm5cqXS9Z4pjJFSipnVO7oYP X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:MN2PR04MB6176.namprd04.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(376002)(136003)(39860400002)(346002)(366004)(396003)(478600001)(31696002)(16526019)(75432002)(6916009)(5660300002)(786003)(66556008)(66476007)(16576012)(316002)(66946007)(36756003)(8936002)(3480700007)(26005)(86362001)(6486002)(52116002)(53546011)(8676002)(83380400001)(186003)(31686004)(956004)(2616005)(2906002)(43740500002); DIR:OUT; SFP:1102; X-MS-Exchange-AntiSpam-MessageData: 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 X-OriginatorOrg: cornell.edu X-MS-Exchange-CrossTenant-Network-Message-Id: 00110581-13f8-452a-314c-08d891914790 X-MS-Exchange-CrossTenant-AuthSource: MN2PR04MB6176.namprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Nov 2020 22:27:23.1671 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 5d7e4366-1b9b-45cf-8e79-b14b27df46e1 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Pg/biaA7raK9i2zL3+KcsusdIqTHGshOM0y/LZuwnrOrGjm9UDX3uyVsC+bejHfOxZsH3VKxbzuz39GbOfvPmQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR04MB5967 X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, JMQ_SPF_NEUTRAL, MSGID_FROM_MTA_HEADER, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_PASS, SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) 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, 25 Nov 2020 22:27:25 -0000 On 11/25/2020 4:47 PM, Norton Allen wrote: > In my recent tests, it appears as though it is not possible to successfully > connect via two Unix Domain sockets from one client application to one server > application. > > Specifically, if I create a server which listens on a Unix Domain socket and a > client, which attempts to connect() twice, both seem to lock up. This is not the > behavior under Linux. > > I will be happy to work up a minimal example if it is helpful in tracking this > down. I wanted to start by asking whether this is a known limitation and/or if > there is something about the Cygwin implementation that makes this sort of thing > very difficult. A minimal example would be extremely helpful. Corinna can answer questions about limitations in the current implementation. But there is a new implementation under development. It's in the topic/af_unix branch of the Cygwin git repository if you're interested in looking at it. Corinna began working on this a couple years ago, and I've recently been trying to finish it. I've made quite a bit of progress, but there's still more to do and undoubtedly many bugs. So any test cases you have would be very useful. Ken