DMARC-Filter: OpenDMARC Filter v1.4.2 delorie.com 58N9pb8B2069415
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 4AAD03858D26
MIME-Version: 1.0
References: <CAN0SSYzFKJoZRU7fCm4YKH5O_J3SMvCjjgfua7zUJQL4Zj3rzA AT mail DOT gmail DOT com>
 <631f0af5-d05c-cb33-956f-b1c284a37766 AT jdrake DOT com>
In-Reply-To: <631f0af5-d05c-cb33-956f-b1c284a37766@jdrake.com>
Date: Tue, 23 Sep 2025 11:49:48 +0200
Message-ID: <CAPJSo4WL5sh-jhAgVq9yZMYVvKT-iq04Ncx5E4yrfd6uQ1+deg@mail.gmail.com>
Subject: Re: Why does Cygwin not use MiCloneProcessAddressSpace() for fork()
To: cygwin AT cygwin DOT com
From: Lionel Cons via Cygwin <cygwin AT cygwin DOT com>
Reply-To: Lionel Cons <lionelcons1972 AT gmail DOT com>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>

On Mon, 22 Sept 2025 at 23:28, Jeremy Drake via Cygwin
<cygwin AT cygwin DOT com> wrote:
>
> On Mon, 22 Sep 2025, Mark Liam Brown via Cygwin wrote:
>
> > Greetings!
> >
> > Why does Cygwin not use MiCloneProcessAddressSpace() for fork()? That
> > function was added for the Windows Services for UNIX, and it still
> > working in Windows 11.
> >
> > Mark
> >
>
> This is a perennial question, and the short answer is that it doesn't play
> well with win32 dlls.  Replies turned up via simple search:
>
> https://cygwin.com/pipermail/cygwin/2016-January/225571.html
> https://cygwin.com/pipermail/cygwin/2018-January/235767.html

Maybe those bugs were fixed in the meantime? UWIN has threads, uses
DLLs (UWIN build DLLs, stock Windows DLLs, 3rd party DLLs, ...) and
obviously has full console support (even tmux works).

I also would be VERY happy to escalate any bugs related to
RtlCloneUserProcess() in Cygwin. Very few things (except proof for
extensions to THE Standard Model) would make me more happy than a
faster (RtlCloneUserProcess() based) fork() in Cygwin.

Lionel

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple