From: Thomas Wolff <towo@towo.net>
To: cygwin@cygwin.com
Subject: Re: select() hanging after terminal killed
Date: Thu, 29 Apr 2010 14:18:00 -0000 [thread overview]
Message-ID: <4BD989A9.4080402@towo.net> (raw)
In-Reply-To: <4BD96D59.7080808@gmx.de>
On 29.04.2010 13:28, Matthias Andree wrote:
> Am 29.04.2010 12:53, schrieb Thomas Wolff:
>
> [on closed terminal]
>
>> On Linux, select() indicates an exception and EIO.
>> On SunOS, select() indicates both an exception and input (weird),
>>
> Not weird, you appear to be misunderstanding select().
> An IEEE Std 1003.1 compliant select():
>
> - only states that a subsequent read() will *not block*
> this includes EOF and error, as they make read() return without blocking)
>
> - makes *no statements about success*
>
Oh, right, so apparently Linux is wrong here (since it does not report
read availability...).
>> On Cygwin, the following is observed:
>> * EOF is not signalled on read(); rather EIO is indicated right away.
>> (Maybe not too bad, an application can handle that as well.)
>> * select() with timeout hangs.
>>
>> Especially the latter can hardly be handled by an application.
>>
> Pointers for workarounds: alarm(), signal().
>
So I could setup alarm() to get myself signal()ed while waiting in a
long sleep().
But the granularity is in seconds only, so this is not a substitute for
most use cases typically handled by calling select().
Thanks for the information anyway.
------
Thomas
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next prev parent reply other threads:[~2010-04-29 13:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-29 11:28 Thomas Wolff
2010-04-29 12:17 ` Matthias Andree
2010-04-29 14:18 ` Thomas Wolff [this message]
2010-04-29 16:40 ` Matthias Andree
2010-04-29 15:19 ` Corinna Vinschen
2010-04-29 15:24 ` Christopher Faylor
2011-05-26 22:44 Thomas Wolff
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