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Re: fork and exec (was: Re: Proposed patch to system.XWinrc)
- From: Christopher Faylor <cgf-use-the-mailinglist-please at cygwin dot com>
- To: cygwin at cygwin dot com
- Date: Wed, 1 Jul 2009 11:11:56 -0400
- Subject: Re: fork and exec (was: Re: Proposed patch to system.XWinrc)
- References: <416096c60906302255t1b5bdb41u442ebca20679c8d9@mail.gmail.com>
- Reply-to: cygwin at cygwin dot com
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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