Subject: Re: bi-directional pipes?
To: Matt Thomas <>
From: David Laight <>
List: tech-kern
Date: 02/04/2003 15:39:43
On Tue, Feb 04, 2003 at 06:22:00AM -0800, Matt Thomas wrote:
> At 06:21 AM 2/4/2003, Paul Kranenburg wrote:
> >Our pipe(2) system call internally creates data structures to enable
> >bi-directional traffic (inherited from FreeBSD). We don't currently
> >use this. We don't even expose it at all since the pipe descriptors are
> >marked read-only and write-only.
> >
> >The question is: do we want to hang on to this?
> >
> >If not, the code can be simplified, which, among other things, would
> >reduce complexity of an MP-safe locking design (something that FreeBSD
> >hasn't got right either, as far as I can tell).
> You can always use socketpair() to get bidirectional pipes.
> So I'd say simplify...

For compatibility with SVR4 we should support bi-directional pipes.


David Laight: