Mailing-List: contact cygwin-help@sourceware.cygnus.com; run by ezmlm List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@sources.redhat.com Delivered-To: mailing list cygwin@sources.redhat.com Date: Tue, 28 Nov 2000 22:52:59 -0500 From: Christopher Faylor To: "cygwin@cygwin.com" Cc: zackw@stanford.edu Subject: Re: [PATCH] Problems with Cygwin mmap/munmap (mmap.cc) Message-ID: <20001128225259.B11647@redhat.com> Reply-To: cygwin@cygwin.com Mail-Followup-To: "cygwin@cygwin.com" , zackw@stanford.edu References: <200011281912.eASJCmf13405@plmlir5.mail.eds.com> <20001128114558.R2285@wolery.stanford.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.11i In-Reply-To: <20001128114558.R2285@wolery.stanford.edu>; from zackw@Stanford.EDU on Tue, Nov 28, 2000 at 11:45:58AM -0800 On Tue, Nov 28, 2000 at 11:45:58AM -0800, Zack Weinberg wrote: >I might point out that we only want these things for mmap of anonymous >memory. If Cygwin used VirtualAlloc instead of CreateFileMapping with >an invalid handle to implement anonymous mmap, then both behaviors >would be implementable easily. (I don't know if this would interfere >with cygwin's brk() implementation, though.) I think that I raised this specter before but, on reflection, this implementation detail should matter. We'd have the same issue with VirtualAlloc or CreateFileMapping. I think that you (Zack) noted that using VirtualAlloc actually might save us some precious upper memory in the Windows 9x "OS"'s. The problem, I think, is that VirtualAlloc space is not inherited. We could kludge around this, like we do with fork, by copying the regions but that could slow down things a lot. The Microsoft docs sometimes seem to imply that you can mark a VirtualAlloc'ed region as shareable but I've never been able to get that to work. cgf -- Want to unsubscribe from this list? Send a message to cygwin-unsubscribe@sourceware.cygnus.com