Re: Windows XP Support

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Jan 11 09:25, Warren Young wrote:
> On Jan 11, 2016, at 4:52 AM, Corinna Vinschen <corinna-cygwin@cygwin.com> wrote:
> > 
> > Continuing support for XP and Server 2003 is really becoming a
> > burden.  It requires to code and maintain workarounds which are not
> > required anymore in newer OSes, so I really would like to get rid of
> > that stuff.
> 
> I seem to recall you saying that Vista added a fork-like facility to
> the kernel which might let Cygwin implement a copy-on-write fork(2).
> Would dropping XP support allow that?

Unfortunately not.  Effectively I begged for it on the Windows MSDN
forums and in private communication with Microsoft, but to no avail
for technical reasons.

The fork-like function (called RtlCloneUserProcess) does not work
reliably with Win32 processes.  The problem is not the function itself,
but the way certain Win32 DLLs are initialized at startup.  The DLL
initialization code won't do the right thing anymore in the child
process and thus stuff doesn't work in the child.  E.g., the connection
to the console Window is broken in the child and no AllocConsole or
AttachConsole call will resurrect it.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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