Re: forked before bash subshell

[Daniel Colascione]

On 10/15/2016 12:23 AM, L. A. Walsh wrote:
> Daniel Colascione wrote:
> > One such case is Cygwin --- I'm not sure how "contrived" it is. Cygwin
> > has an old-fashioned non-COW fork, and to add insult to injury,
> > process creation generally is very slow (~100ms). It pays to eliminate
> > subshells in that environment.
> Given what Cygwin has to work around in Windows -- it is very contrived.

Maybe the internals. From the perspective of programs like bash, Cygwin 
is a mostly ordinary POSIX environment, one with lots of users and that 
deserves full support.

> MS has copy-on-write available to MS processes, that it's not usable in
> Cygwin isn't surprising given that most of Windows is closed-source.

It has nothing to do with being closed source and everything to do with 
the win32 subsystem (under which Cygwin runs) not being designed to cope 
with process duplication.

> But if you really want bash on your windows, use a native copy.  It's
> not as likely to have the same problems
> (https://techcrunch.com/2016/03/30/be-very-afraid-hell-has-frozen-over-bash-is-coming-to-windows-10/)

It doesn't do the same thing. Cygwin is an integrated POSIXish environment.

> Apparently there is a Windows Subsystem for Linux that is currently in Beta
> for Win10:
> http://www.howtogeek.com/265900/everything-you-can-do-with-windows-10s-new-bash-shell/

SFU and similar do not interact with the win32 subsystem as closely as 
Cygwin and so can't provide the same experience. IMHO, you might as well 
run a VM.