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From: Pankaj Yadav <pankajdnapster@gmail.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@cygwin.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

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