Re: Rationale for paccept() sigset argument?

["Michael Kerrisk" <mtk.manpages@googlemail.com>]

[CC+=Roland]

On 9/2/08, Michael Kerrisk <mtk.manpages@googlemail.com> wrote:
> Ulrich Drepper wrote:
> > On Wed, Aug 20, 2008 at 9:50 AM, Michael Kerrisk
> > <mtk.manpages@googlemail.com> wrote:
> >
> > > What is the rationale for the sigset argument of paccept()?
> > >
> >
> > accept, like select/poll, is used often as a function to dealy
> > operation.  Unlike read, recv, etc, which are handled using O_NONBLOCK
> > and select/poll.  pselect/ppoll do not really have a sigset parameter
> > to handle signals in general.  You use it to enable special handling
> > in case of blocking.  Example: if you want to implement userlevel
> > context switching, you dedicate a signal to wake up any blocked
> > thread.  Since accept falls more into the same category than poll,
> > this means the sigset parameter is justified.  In theory we could add
> > it to all functions but there is no reason to do this without any
> > other reason to change the interface.
> >
>
>
> Ulrich, you snipped a relevant piece of my earlier message:
>
> [[
> > * It seems to me that any case where we might want to use paccept() could
> be
> > equivalently dealt with using the existing
> pselect()/ppoll()/epoll_pwait()
> > followed by a conventional accept() if the listening file descriptor
> > indicates as ready.
> ]]
>
> So I'll rephrase: what use case does the sigset argument of paccept()
> allow us to handle that couldn't equally have been handled by
> pselect()/ppoll()/epoll_pwait() + traditional accept()?
>
>
> Cheers,
>
> Michael
>
> --
> Michael Kerrisk
> Linux man-pages maintainer;
> http://www.kernel.org/doc/man-pages/
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