Mailing-List: contact cygwin-developers-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-developers-subscribe AT sources DOT redhat DOT com>
List-Archive: <http://sources.redhat.com/ml/cygwin-developers/>
List-Post: <mailto:cygwin-developers AT sources DOT redhat DOT com>
List-Help: <mailto:cygwin-developers-help AT sources DOT redhat DOT com>, <http://sources.redhat.com/ml/#faqs>
Sender: cygwin-developers-owner AT sources DOT redhat DOT com
Delivered-To: mailing list cygwin-developers AT sources DOT redhat DOT com
Message-ID: <003a01c0c714$c59789d0$0200a8c0@lifelesswks>
From: "Robert Collins" <robert DOT collins AT itdomain DOT com DOT au>
To: <cygwin-developers AT cygwin DOT com>
Subject: file change notifications - the unix model is?
Date: Tue, 17 Apr 2001 18:02:32 +1000
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 5.50.4133.2400
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400
X-OriginalArrivalTime: 17 Apr 2001 07:55:16.0746 (UTC) FILETIME=[BDB55EA0:01C0C713]

It think the title pretty much sums it up.

I am currently doing a documentation search, but perhaps one of you folk
can give me a name to search for.  This is for /etc/passwd parsing.

As I see it we can
a) use win32 filechange notification semantics. This may involve being
notified on writes to /etc and then checking the date on /etc/passwd, or
I may be able to be informed about /etc/passwd directly - not sure yet.
The ugly thing is we'd have to get the win32 path, and then get told
about mount point changes.
b) implement the unix model, and have that model be mount point change
aware. This has the advantage of reusability, and possibly adding extra
external functionality as well.

--- possible different approach---
memory map /etc/passwd and parse it every time. As there'd be no file
read overhead, and it should get very high cache hit rates this should
be pretty quick. I'm willing to do a test implementation for testing to
see if it does have the same perf hit as parsing via file read/writes
every time.

Rob