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
From: "Michael Clarke" <mclarke AT timetra DOT com>
To: <cygwin AT cygwin DOT com>
Subject: fhandler pointers to cygwin shared memory during fork
Date: Mon, 23 Feb 2004 12:30:58 -0000
Message-ID: <001801c3fa08$e4eb3cd0$1a0016ac@eng.timetra.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
X-OriginalArrivalTime: 23 Feb 2004 12:31:00.0865 (UTC) FILETIME=[E5351710:01C3FA08]


Hi folks,

I've been writing a Cygwin application that uses a DLL that maps memory
at the same virtual address as the default cygwin_shared address
(0x0A000000). My DLL maps the memory before Cygwin's dll_entry point is
called. I notice that open_shared correctly maps Cygwin's shared memory
area at a different virtual address to the default. However, tty file
handlers take a pointer (tc in class fhandler_termios) to the tty list
held in this shared memory area. During a fork, this pointer is copied
and never fixed up to account for differing cygwin_shared addresses
between parent and child. My question is, is it a goal of Cywgin to
avoid copying pointers to the shared memory areas during a fork?

Thanks,

Michael.



--
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/