From: "Morris, Chris" <chris.morris@...>
Date: 2002-03-20T03:03:58+09:00
Subject: RE: Development of Windows version of Ruby

Here's an overview of fork on Windows with Perl. (Google rocks):

ActiveState announced an agreement with Microsoft to help with Perl on
Windows that included the addition of fork emulation (June 1999):
http://www.perl.com/pub/a/1999/06/activestate.html


ActiveState added fork support for Perl on Windows with ActiveState Perl
5.6:
http://www.activestate.com/Corporate/Communications/Releases/Press971298169.
html


The current release is 5.6.1.631. Release notes here:
http://aspn.activestate.com/ASPN/Reference/Products/ActivePerl/RELEASE.html

They state: "The fork() emulation has known limitations. See perlfork for a
detailed summary"


Here's the perlfork docs:
http://aspn.activestate.com/ASPN/Products/ActivePerl/lib/Pod/perlfork.html

They state:

  WARNING:  As of the 5.6.1 release, the fork() emulation continues to be an

  experimental feature.  Use in production applications is not recommended. 
  See the "BUGS" and "CAVEATS AND LIMITATIONS" sections below.

  Perl provides a fork() keyword that corresponds to the Unix system call of

  the same name. On most Unix-like platforms where the fork() system call is

  available, Perl's fork() simply calls it.

  On some platforms such as Windows where the fork() system call is not 
  available, Perl can be built to emulate fork() at the interpreter level. 
  While the emulation is designed to be as compatible as possible with the 
  real fork() at the level of the Perl program, there are certain important 
  differences that stem from the fact that all the pseudo child 
  ``processes'' created this way live in the same real process as far as the

  operating system is concerned.

  This document provides a general overview of the capabilities and 
  limitations 

So ... in 2-3 years, with Microsoft's help, fork support in ActiveState Perl
for Windows is still sketchy, which greatly amplifies Mark's question:

  "how important is the lack of a True Fork"

Chris