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Date: Fri, 15 Dec 2000 21:09:40 -0500
From: Christopher Faylor <cgf AT redhat DOT com>
To: cygwin-developers AT cygwin DOT com
Subject: Re: Serial blocking read
Message-ID: <20001215210940.A12596@redhat.com>
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References: <Pine DOT GSO DOT 4 DOT 21 DOT 0012151727280 DOT 7629-100000 AT myth8 DOT Stanford DOT EDU>
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In-Reply-To: <Pine.GSO.4.21.0012151727280.7629-100000@myth8.Stanford.EDU>; from cobbler@stanford.edu on Fri, Dec 15, 2000 at 05:38:09PM -0800

I think this is coming from fhandler_serial.cc but I don't know for
sure.  Can you provide a unified diff?  A complete unified diff will
show the filename and give a little more context.

The contributing link on http://cygwin.com should give you some pointers on how
to do this and how to provide a patch.

cgf

On Fri, Dec 15, 2000 at 05:38:09PM -0800, Dan Morris wrote:
>Has anyone else had problems with serial port reads blocking even when
>O_NONBLOCK is passed to _read in the 1.1.6-1 DLL?
>
>I noticed that my reads were appropriately non-blocking most of the time, but
>blocked whenever "overlapped_armed" was set, because in this case raw_read
>never finds out how many bytes are in the serial port's buffer.  This patch
>seems to fix the problem for me :
>
>121a122,128
>>       if (overlapped_armed) {
>>           if (!ClearCommError (get_handle (), &ev, &st))
>> 	          goto err;
>>           else if (st.cbInQue)
>>             inq = st.cbInQue;
>>       }
>> 
>
>If anyone else has found a better solution to this problem, let me know...
>otherwise perhaps this patch will fix things.
>
>-Dan
> 
>Dan Morris
>http://techhouse.brown.edu/dmorris
>
>Tiqit Computers
>http://www.tiqit.com
>

-- 
cgf AT cygnus DOT com                        Red Hat, Inc.
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