delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2014/01/15/11:50:54

X-Recipient: archive-cygwin AT delorie DOT com
DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
:list-unsubscribe:list-subscribe:list-archive:list-post
:list-help:sender:date:from:to:subject:message-id:reply-to
:references:mime-version:content-type:in-reply-to; q=dns; s=
default; b=bHVUyZzPVsJ8VIi2pe6i+Qg0icqlqWQg4soXhAsFV1M3upaXDZsHV
Lr9+HzzlvooOJF6HBlr21zwXHM5lK9ZkXsUnKYejZMd2hrCLjX0+KhVZ++zI+yLA
wKA+Hps7BBgqpCo5w//XxwYdI+OpQ8KZVa6yUWWE/GjJ6pBGzPsimM=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
:list-unsubscribe:list-subscribe:list-archive:list-post
:list-help:sender:date:from:to:subject:message-id:reply-to
:references:mime-version:content-type:in-reply-to; s=default;
bh=lOcjaBuf2AJeiYodchbaimycp5Y=; b=ygcFG5MY4X54pPdfsAemAvrs9Jwb
KvW0iT/QmNsJv5Jcmhuwn5WLuyIBUNtq5JoFFxzSEz5KLbsy6aHydSYPeBWhdfpm
IAG4qknRerpdVQo6/lY9sniTngDgUxOYnkCpTQVrXrMaz1qP70vwGI9VdhdDl43O
CWGX3NryrXwQ1xU=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
Authentication-Results: sourceware.org; auth=none
X-Virus-Found: No
X-Spam-SWARE-Status: No, score=-6.0 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.3.2
X-HELO: calimero.vinschen.de
Date: Wed, 15 Jan 2014 17:50:31 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: fork() + file descriptor bug in 1.7.27(0.271/5/3) 2013-12-09 11:54
Message-ID: <20140115165031.GA30785@calimero.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <831845 DOT 98759 DOT bm AT smtp116 DOT sbc DOT mail DOT ne1 DOT yahoo DOT com> <52D6B9DC DOT 50903 AT coverity DOT com>
MIME-Version: 1.0
In-Reply-To: <52D6B9DC.50903@coverity.com>
User-Agent: Mutt/1.5.21 (2010-09-15)

--6c2NcOVqGQ03X4Wi
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Jan 15 11:39, Tom Honermann wrote:
> On 01/13/2014 11:06 AM, tednolan AT bellsouth DOT net wrote:
> ...
> >		switch (fork()) {
> >=09=09=09
> >			/* error */
> >			case -1:
> ...
> >			/* child */
> >			case 0:
> >				fprintf(stderr, "child\n"); fflush(stderr);
> >				exit(0);
> >				break;
>=20
> The above code is incorrect.  It is always wrong to call exit() from
> a forked process that has not yet called one of the exec() family of
> functions.  _exit() should be called instead.  Best case, calling
> exit() will result in double flushing of any stream buffers held by
> the parent at the time fork() is called (since the buffers will
> (eventually) be flushed by the parent as well as the child (unless
> at least one of the processes aborts or exits with _exit()).

Still, SUSv4 says:

  The exit() function shall then flush all open streams with unwritten
  buffered data and close all open streams. Finally, the process shall
  be terminated [...]
=20
Note that exit only flushes streams with *unwritten* data, but not
streams with *unread* data.  So this testcase is still valid and
should work.


Corinna

--=20
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

--6c2NcOVqGQ03X4Wi
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1
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=6J3O
-----END PGP SIGNATURE-----

--6c2NcOVqGQ03X4Wi--

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019