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
Message-ID: <3F2C7F4B.50501@santafe.edu>
Date: Sat, 02 Aug 2003 21:19:39 -0600
From: "Marcus G. Daniels" <mgd AT santafe DOT edu>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: cygwin AT cygwin DOT com
Subject: Re: loading DLLs created with Cygwin into Sun JDK
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

> Interesting -- if I add the -Xmx256m flag to `java', my test case 
> works too.


The cause is the fixed `cygwin_shared_address' (set to 0xa000000 in 
winsup/cygwin/shared_info.h).  What happens with Sun JVM loads of 
Cygwin-dependent DLLs is that chunk of virtual memory gets claimed by 
the JVM, and then `open_shared' (in winsup/cygwin/shared.cc) defaults to 
a second MapViewOfFileEx after failing in its attempt to map the fixed 
address.  The second MapViewOfFileEx attempt has a comment that says 
"Probably win95, so try without specifying the address", which doesn't 
seem to be desirable in this case. 

When I rebuilt the Cygwin DLL using 0x20000000 the load of my set of 
DLLs work fine (without the -Xmx256m flag, which was presumably just 
pushing VM allocation blocks around).

Incidentally, does anyone know of a Windows application that can be used 
to see the VM maps in a given process.
(Like in Linux, with /proc/PID/maps?)


--
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/