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From: Enrico Forestieri <forenr@lyx.org>
To: cygwin@cygwin.com
Subject: Re: FIFO issues
Date: Tue, 20 Sep 2022 00:05:57 +0200	[thread overview]
Message-ID: <1b28b650-b588-e34f-919e-e75f5a01196f@lyx.org> (raw)
In-Reply-To: <a3084ca6-ea7b-535c-c0fb-2c29e20b7ddb@cornell.edu>

[-- Attachment #1: Type: text/plain, Size: 1141 bytes --]

Ken Brown wrote:

 > I did an internet search on this issue and found the following, which 
describes the

 > situation we're discussing:

> https://stackoverflow.com/questions/14594508/fifo-pipe-is-always-readable-in-select  

 > According to that post, select on Linux will wait for a writer the 
first time it's

 > called to check read readiness for a FIFO opened for reading with 
O_NONBLOCK set.

 > But if the writer then closes the FIFO, subsequent calls to select 
will always find

 > the FIFO read ready (and read will return 0). This behavior is not 
documented, as far as

 > I can tell, and in fact it contradicts the existing documentation 
(both POSIX and Linux).

 > So I don't think someone trying to write a portable program should 
rely on it.


Please, note that this code was working on cygwin the way it works on 
linux until some

time ago, maybe last year, I am not sure. I also found this 
stackoverflow discussion:

https://stackoverflow.com/questions/28851639/select-with-non-blocking-reads

I tried the code also on Solaris and NetBSD and it works exactly as on 
linux, so I think

it is portable.


-- 

Enrico

  parent reply	other threads:[~2022-09-19 22:06 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-18 21:45 Enrico Forestieri
2022-09-19 19:15 ` Ken Brown
2022-09-19 19:50   ` Norton Allen
2022-09-19 19:53     ` Norton Allen
2022-09-19 21:25       ` Ken Brown
2022-09-19 21:28         ` Norton Allen
2022-09-19 22:05         ` Enrico Forestieri [this message]
2022-09-19 23:54           ` Ken Brown
2022-09-20  3:51             ` [EXTERNAL] " Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2022-09-20  6:54             ` Enrico Forestieri
2022-09-20 13:18               ` Ken Brown
2022-09-20 17:20                 ` Enrico Forestieri
2022-09-23 15:36                   ` Ken Brown

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