vfork() question

vfork() question

[Bence Szépkúti]

Hello,

I was poking around in the fork() code in Cygwin, and was wondering if
someone could explain to me / point me to a discussion of why the NEWVFORK
code was abandoned.

I realise that this code had been disabled as "not working" since 2008,
however I am interested in why this was the case. Was the concept behind
"short-circuiting" vfork itself unfeasible in the context of Cygwin? Was a
compatible implementation too complex / too slow to be worth it compared to
a regular fork?

Any insight is appreciated.

Thanks,
Bence

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Re: vfork() question

[Andrey Repin]

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Greetings, Bence Szépkúti!

> Hello,

> I was poking around in the fork() code in Cygwin, and was wondering if
> someone could explain to me / point me to a discussion of why the NEWVFORK
> code was abandoned.

> I realise that this code had been disabled as "not working" since 2008,
> however I am interested in why this was the case. Was the concept behind
> "short-circuiting" vfork itself unfeasible in the context of Cygwin? Was a
> compatible implementation too complex / too slow to be worth it compared to
> a regular fork?

> Any insight is appreciated.

I could be wrong, but it may be due to a more reliable ways to implement
forking that became available in Win7+.


-- 
With best regards,
Andrey Repin
Saturday, July 27, 2019 13:34:49

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Re: vfork() question

[Corinna Vinschen]

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On Jul 27 12:02, Bence Szépkúti wrote:
> Hello,
> 
> I was poking around in the fork() code in Cygwin, and was wondering if
> someone could explain to me / point me to a discussion of why the NEWVFORK
> code was abandoned.
> 
> I realise that this code had been disabled as "not working" since 2008,
> however I am interested in why this was the case. Was the concept behind
> "short-circuiting" vfork itself unfeasible in the context of Cygwin? Was a
> compatible implementation too complex / too slow to be worth it compared to
> a regular fork?

This was long ago and the original developer hacking this code isn't
with us anymore.  The only vague recollection I have is that it never
really worked right, but no details.  Maybe searching the mailing list
archives helps unearthing some of the problems.


Sorry,
Corinna

-- 
Corinna Vinschen
Cygwin Maintainer

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