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Date: Sat, 08 Dec 2001 17:30:40 -0500
To: cygwin AT cygwin DOT com
From: "Pierre A. Humblet" <Pierre DOT Humblet AT ieee DOT org>
Subject: Re: More exim, and fcntl lock problems
In-Reply-To: <3.0.5.32.20011208165955.008351e0@pop.ne.mediaone.net>
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>"Pierre A. Humblet" wrote:
>
>2) On WinNT, local deliveries fail on line 765 of transport.c
>  while ((len = read(deliver_datafile, deliver_in_buffer,
>I reproduced the situation in the attached try.c  
>A parent process opens and locks a file (using fcntl), 
>and then forks a child. It turns out that the child cannot 
>read the file. Is it a Cygwin bug (latest everything)?

This answers my own question to close this matter.

Cygwin's file locking is based on Windows LockFileEx(), which 
uses a mandatory locking method, rather than a cooperative one
as in Unix. For a tutorial, see e.g.
http://www.netapp.com/tech_library/3024.html  

Making Cygwin's locking more Unix-like would be a big task.
If you run into this issue my advice is to modify the 
application.

Pierre

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