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Date:	Wed, 1 Jul 2009 11:11:56 -0400
From:	Christopher Faylor <cgf-use-the-mailinglist-please AT cygwin DOT com>
To:	cygwin AT cygwin DOT com
Subject:	Re: fork and exec (was: Re: Proposed patch to system.XWinrc)
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On Wed, Jul 01, 2009 at 06:55:35AM +0100, Andy Koppe wrote:
>2009/6/23 Christopher Faylor:
>>>If posix_spawn() ever gets implemented in Cygwin to
>>>avoid the slowness of fork(), /bin/sh might well change to the first
>>>shell that supports it.
>>
>> It's really somewhat of an urban myth about Cygwin's fork being slow.
>> Cygwin's exec is also pretty slow. ??I'm not really sure that posix_spawn
>> would cause any kind of performance improvement.
>
>Ah, right. So is it Windows' CreateProcess() itself that's slow? Or is
>it some of the additional stuff that exec() needs to deal with?
>Signals? The hidden console?

The majority of the exec code is in spawn.cc - spawn_guts().  You can
see for yourself that this is not a simple function.

Just remember that neither fork nor exec have native Windows analogues.

cgf

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