delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2003/07/17/03:45:13

Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sources.redhat.com/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
Date: Thu, 17 Jul 2003 09:44:53 +0200
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: configure and mmap on Cygwin
Message-ID: <20030717074453.GY1733@cygbert.vinschen.de>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <Pine DOT WNT DOT 4 DOT 56 DOT 0307161729140 DOT 1096 AT pervalidus>
Mime-Version: 1.0
In-Reply-To: <Pine.WNT.4.56.0307161729140.1096@pervalidus>
User-Agent: Mutt/1.4.1i

On Wed, Jul 16, 2003 at 05:39:22PM -0300, Fr?d?ric L. W. Meunier wrote:
> I noticed configure always return
> 
> checking for working mmap... no

Yeah, that's unfortunate.  I'm seeing the same all the time.

> I found the following posts from Corinna
> 
> http://www.cygwin.com/ml/cygwin/2002-04/msg00412.html
> http://mail.gnu.org/archive/html/autoconf-patches/2000-10/msg00241.html
> 
> The question is if I should just ignore this test or add
> #define HAVE_MMAP 1 to config.h before make.

It depends.  The Cygwin mmap implementation should work in 99% of the
cases.  There's one case which will never work:

   mem = malloc(sizeof(blah));
   mmap (mem, ..., MAP_FIXED, ...);

since Windows doesn't support memory maps on already allocated memory.
If your application does this (not many today), you're out of luck. 
Otherwise you should be fine using mmap.

Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                                mailto:cygwin AT cygwin DOT com
Red Hat, Inc.

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

- Raw text -


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