DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:mime-version:from:date:message-id:subject:to
	:content-type; q=dns; s=default; b=bG5Tvci8z8uxeEy6v4UfzSZ/pAMs0
	9PSyTmJLy0Pj8EX1XM227CO1FkD7jBEte8gsCZNkHr4TXP7WI48jiBkdutZuLEtS
	1RYIh9FvzCIL3wUnm1Nv4hMHg0n5B9W9SNqs3yhCM0JVhWC7Rmal9LcoLNX4r/jN
	P3i8SwXb7ql5c8=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
MIME-Version: 1.0
From: Pankaj Yadav <pankajdnapster AT gmail DOT com>
Date: Tue, 16 Aug 2016 00:04:23 +0530
Message-ID: <CAAPqxJx+EPpzESWMOXowp3grKubWJJ7n93ftFPK1L3MKWkqrLQ@mail.gmail.com>
Subject: On WIN7, write() not returning immediately even on non-blocking sockets
To: cygwin AT cygwin DOT com
Content-Type: text/plain; charset=UTF-8

Hi,
We have a proxy server type of program which has an infinite loop
writing to sockets with write() call.

All of the sockets are set to non-blocking mode.It works fine on linux
and all windows versions except win7(both 32 and 64 bit).We tested on
hundreds of computers.

The code where it gets stuck is

printf("Nonblocking:%d\n",(fcntl(t_qelem->respsock, F_GETFL, 0) &
O_NONBLOCK))?1:0;
i = write(t_qelem->respsock,&t_qelem->webtoresp[t_qelem->webtorespsent],t_qelem->webtoresplen-t_qelem->webtorespsent);
printf("written\n");

Output is :  Non-blocking:1 and then it does NOT print "written" ever.

I also tried to do some debugging using gdb.
write() -> send_internal()  ->{looping through fhandler_socket::wait_for_events}
even when the socket is set to blocking mode.

I am ignoring SIGPIPEs but I know that it probably happens only when
the connection has closed from the other side coz it happens when i
close the browser which is using this proxy software.Can you please
help me out, if i am doing something wrong.

Thanks
-- 
--
Regards
Pankaj Yadav

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