From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from endymion.arp.harvard.edu (endymion.arp.harvard.edu [140.247.179.94]) by sourceware.org (Postfix) with ESMTPS id 1F9883851C1A for ; Wed, 25 Nov 2020 21:47:20 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 1F9883851C1A Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=huarp.harvard.edu Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=allen@huarp.harvard.edu Received: from [192.168.7.23] (pool-74-104-152-231.bstnma.fios.verizon.net [74.104.152.231]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by endymion.arp.harvard.edu (Postfix) with ESMTPSA id A2E896C095A for ; Wed, 25 Nov 2020 16:47:19 -0500 (EST) To: "cygwin@cygwin.com" From: Norton Allen Subject: Unix Domain Socket Limitation? Message-ID: <71490665-31b0-f63c-74da-461a053fac21@huarp.harvard.edu> Date: Wed, 25 Nov 2020 16:47:16 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.12.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Spam-Status: No, score=-3.7 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, RCVD_IN_DNSWL_LOW, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham 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 21:47:21 -0000 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.