Date: Sun, 11 Apr 2010 01:48:51 -0400
From: tmhikaru AT gmail DOT com
To: cygwin AT cygwin DOT com
Subject: Usage of _exit(0) closes fd's of parent process
Message-ID: <20100411054851.GA25578@roll>
Mime-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha1; 	protocol="application/pgp-signature"; boundary="BOKacYhQ+x31HxR3"
Content-Disposition: inline
User-Agent: Mutt/1.4.2.3i
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

--BOKacYhQ+x31HxR3
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

	Hi. I'm having an unusual problem in a program I'm trying to get
working in cygwin. My program fork()'s a child process to do a hostname
lookup, establishes a tcp connection in the parent, then has the child
_exit(0) itself. For some reason I don't understand, _exit is not just
closing the fd's of the child, but of the parent as well. From my
understanding, _exit is supposed to close the fd's of the process it is run
from only.

	The program works correctly (That is to say, stays connected) if I
comment out the _exit and instead have it while (1) { sleep (10000); }.
Obviously I would like to be able to kill off the child at some point, but
for testing this proved to me that either my expectation of how _exit is
supposed to work in cygwin is flawed, or _exit is.

	Please let me know if I'm using this function call incorrectly, and
what behavior I should be expecting. If my expectation of how _exit is
supposed to act is correct, let me know and I'll file a bug report.


	I am not subscribed to the cygwin mailing list, so please make sure
replies are sent to my email address as well as the list.

Thank you,
Hikaru
--BOKacYhQ+x31HxR3
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (GNU/Linux)

iQEVAwUBS8Fiw5EncCrqzVruAQJiwQgAuBgIdkMC4EsHBNSBmUrFraXu/NCvq1Ja
SDjidNJ6bMdCGAeuYcXGUnSZWkWgjub9mTaWv923RtqUSWWtXbZKkdwdz0AwxO2d
DZjKrNADy7XxAnaEgm6CXeUzO7xYsb/6/l32+arCVFB0b6YGidBU2IFL3+WS2ArT
a3DT7i0qmtyIvR89s+g17WMAcMuAUH6UF2zchUuEmAZzwHhaneIY4j1T5EPMptiw
7ysILUUJ2+rHi37PUqMOvdrcJOOIfXOO6ybQ+gSL8urRAWcKFPuEQvaBpIROgruT
IgYeFp7WzzMRqfqcBVxzcGS5RvdsB/Vr2YKOEzBqMtV5ATd8Y2xYoQ==
=MetO
-----END PGP SIGNATURE-----

--BOKacYhQ+x31HxR3--