DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 537FWR5q1492562
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org F1A863845872
To: Yuyi Wang <Strawberry_Str@hotmail.com>
CC: "cygwin@cygwin.com" <cygwin@cygwin.com>
Subject: RE: [EXTERNAL] Re: unix socket hang when connect
Thread-Topic: [EXTERNAL] Re: unix socket hang when connect
Thread-Index: AQHbp5jKUrkL6l23f0mADm7jeJ5cy7OX7PsAgABljPA=
Date: Mon, 7 Apr 2025 15:30:08 +0000
Deferred-Delivery: Mon, 7 Apr 2025 15:29:16 +0000
Message-ID: <PH0PR09MB109416D36238000B37F545087A5AA2@PH0PR09MB10941.namprd09.prod.outlook.com>
References: <20250407173937.3c2c1e2d5e148b446a558ff4@nifty.ne.jp>
 <TYCPR01MB10926D4FEF9331D030F4551DEF8AA2@TYCPR01MB10926.jpnprd01.prod.outlook.com>
In-Reply-To: <TYCPR01MB10926D4FEF9331D030F4551DEF8AA2@TYCPR01MB10926.jpnprd01.prod.outlook.com>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?VD0BljhmyzViaBbUyLUE3yNXe5eHPwfzH1n4/gdTeBaRa2On7yh7u4aXJZp6?=
 =?us-ascii?Q?asHkQ+fAnV7GbHSV6bvwGWhrX3/Vmq+vljJvLtdhSRRXF6CrQjRUbzoHwT2n?=
 =?us-ascii?Q?JS95mINkm7FDdh1CW9fLkEwYTA2q2gTSQwXMVveOYJdltcs1CxvoUsAYMWKr?=
 =?us-ascii?Q?9lpOvcrAClrfoPEVfoE33vHKoU4xAWypMZlPd3Rm2cH66OcLYrHy+o8y4iJ9?=
 =?us-ascii?Q?L/9zk1g7Mp9O19wKlAxTudCAXsWsye2asi29LEmmn6JgpAB/QOcCC8ddCA7E?=
 =?us-ascii?Q?ic5KVEX+l+UCerhFYFbXvu1XGkaUejy5+h/W3sQJjaVkibkzs2GL+Txcgp+I?=
 =?us-ascii?Q?0qBkbmsZaEN22jEnAfKR4acthwlOdHN5rW/xHihngqG1Lpt9C1O7UwLHwGtJ?=
 =?us-ascii?Q?WQ2D47KtJUaZGG528BC3aN8fX/rAotgNW/kMFBzjsJCCh+kKGE8eU25ymKnf?=
 =?us-ascii?Q?KUR2Ib/uc26cpw2Uw/V1toADf0Ft9NkpL721iStA+2mO5/22jl7EoS43VFl0?=
 =?us-ascii?Q?Bti04mANFlKOy6PNAO/MgFdeA5rNl321RvFXSIDi7ByxHw762MJcR2Q0FSFv?=
 =?us-ascii?Q?zytI1BWyLTPCU+HeiHKf1huoi12EsW2cHk/fmPeyZE+v4zpISsd3UISLax1v?=
 =?us-ascii?Q?XV3RpT3fppC8p5+s+Qz7aKAp0lpt/JaNQlFt2Xu8t6jCVqbvBdFzP/0/BnRE?=
 =?us-ascii?Q?j7CB2/s9pHSAoaudNMGQH2KpjiOytPep2neYwAp75IR8PBofnD2D9vR3VpcD?=
 =?us-ascii?Q?yXHnWa+U0qgtP4l1f2RlA1IKqSRlGuKhLoB/hw0P3zgZ92BeHth367rfQV0A?=
 =?us-ascii?Q?K3A1g/S4ZiXHLjFoxux2P7uMBpm7rILZM7KCAdk7/b6Ea6H4BfZZgUYwTH/b?=
 =?us-ascii?Q?S6ByxCVr69PtE7r/97ZIRFVRYW6sfnF8Tqmgg7fRP/afOdUKGDJJZNPr9ROe?=
 =?us-ascii?Q?pFwLnW2OKjgnHbort3Boo1s2XoQ+8WRG/afDkCnYxJhywFeLDbg9NPu/WaML?=
 =?us-ascii?Q?1xDH4niPwcPAj0m5t21xVGZhuGg5DheIgPXrkFpSz58wTZ/+cme4uvkQRbno?=
 =?us-ascii?Q?dk//o8awyIEbrQn2QcI7XN13W4U7jkRPUiaslsARSETIoH3Tpq/Cl5W7Q4yo?=
 =?us-ascii?Q?8+bjRZjGtlYumy4V/Y5SnOdOb8sycSxr0aNi0x1pIvYmB9wA3jIKqCVIBKzE?=
 =?us-ascii?Q?HvcgB7bDc4vh/V+toL1V0qks8UhYSj4fLMag9wFk5tKkRv2qKV9qIOLsNrxR?=
 =?us-ascii?Q?pnRLiI8wRGo4NF/2q9wImGzUgJG1oTIacNyA9BZcckiWUppjJydOg0cwSILt?=
 =?us-ascii?Q?vseuafgvh+IPb6TUv+dB0fr/DP84ZEQDhvrZqbbepx4FYxLtiiHQsuu+c7c5?=
 =?us-ascii?Q?TsAYsWHfep+XIsTa/xSNMMkZHa7EZpvlKSIiGiAmhJ7uD3HA7HzyQq68bDuA?=
 =?us-ascii?Q?MMu8ZK/451KAGpJ0Dsd0TbcEpl+APRE1kgnElQxMSveWZeVd9xUSezqaypMO?=
 =?us-ascii?Q?HvufgKvd4jDt9tCsvOQJmDL/4kZGJEljBwhYRFvGWO9hHNvL6G7wxADJdIUf?=
 =?us-ascii?Q?QNuDTYt58rD+iQ8NRWw=3D?=
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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
X-OriginatorOrg: ncbi.nlm.nih.gov
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: PH0PR09MB10941.namprd09.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: f3d48682-daef-449b-f4cd-08dd75e91cdc
X-MS-Exchange-CrossTenant-originalarrivaltime: 07 Apr 2025 15:30:22.7952 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 14b77578-9773-42d5-8507-251ca2dc2b06
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW4PR09MB10343
X-BeenThere: cygwin@cygwin.com
X-Mailman-Version: 2.1.30
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin@cygwin.com>
List-Help: <mailto:cygwin-request@cygwin.com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request@cygwin.com?subject=subscribe>
From: "Lavrentiev, Anton \(NIH/NLM/NCBI\) \[C\] via Cygwin" <cygwin@cygwin.com>
Reply-To: "Lavrentiev, Anton \(NIH/NLM/NCBI\) \[C\]" <lavr@ncbi.nlm.nih.gov>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie.com@cygwin.com>

> I'm agree with you, but on other *nix platforms, and even on Windows with
> winsock and AF_UNIX, connect() doesn't wait for accept(). I would like such
> behavior.

The behavior that connect() does not require accept() from the other end is platform-specific.
It's your other system's courtesy, actually, to acknowledge the connection before the user code calls accept().  But it is not guaranteed.

> setting SO_PEERCRED on the client socket works.

This is again a kludge, which is not designed (in general of what SO_PEERCRED is supposed to do) to address the situation above.  Yes, it makes it work, in this particular case on this particular platform (Cygwin), but it won't have the same effect on some other Unix platform that wants to get accept() in the user code and that doesn't ack the connection without it, otherwise.

$.02,

Anton Lavrentiev
Contractor NIH/NLM/NCBI


-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple