Re: Porting vfork()
David Feuer (dfeuer@his.com)
Mon, 11 Jan 1999 17:14:07 -0500
Horst von Brand wrote:
>
> Tim Smith <tzs@tzs.net> said:
> > On Sun, 10 Jan 1999, Torbjorn Lindgren wrote:
> > > The requirements are basically (paraphrased):
> > > * Don't modify any data other than a variable of type pid_t used to store
> > > the return value from vfork()
> > > * Don't return from the function in which vfork() was called.
> > > * Don't call any functions before successfully calling _exit(),or one of
> > > the exec family of functions.
>
> > That last requirement seems overly stringent. I'd expect the child to be
> > able to (and need to) call open, close, dup, fcntl, etc., to deal with
> > IO redirection before calling exec.
>
> Then you can't use vfork(2), you must use fork(2).
>
> All this trouble to shave off a fraction of a percent on a libc build. I
> just don't get it.
>
> [The BSD folks claim "a few seconds less in a libc build", let's make that
> 5 seconds out of 30 minutes (this should be generous). That makes a full
> 0.27%.]
> --
> Dr. Horst H. von Brand mailto:vonbrand@inf.utfsm.cl
> Departamento de Informatica Fono: +56 32 654431
> Universidad Tecnica Federico Santa Maria +56 32 654239
> Casilla 110-V, Valparaiso, Chile Fax: +56 32 797513
A libc build may be a bad example..... A mail server or news
server could be a better one.
--
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David Feuer
dfeuer@his.com
dfeuer@binx.mbhs.edu
Open Source: Think locally; act globally.
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