Re: PROPOSAL: extend pipe() to support NULL argument.

[Albert ARIBAUD]

Changli Gao a Ãcrit :
> On Mon, Jul 6, 2009 at 2:15 PM, Albert ARIBAUD<albert.aribaud@xxxxxxx> wrote:
> > > pipe doesn't support llseek.
> > I wasn't thinking of actively seeking a file position, but simply that reads
> > and writes were independent (and both variable) in size, thus even without
> > (l)seeking, each endpoint has an independent read (resp. write) position to
> > track what's been read from (resp.written into) it at any time, and such a
> > position is, IIUC, single for a given fd, making a fd (a struct file)
> > insufficient for representing a pipe.
> >
> > Amicalement,
> > --
> > Albert.
> pipe doesn't refer to pos when reading or writing. Please refer to
> pipe_read() and pipe_write() for more detail.

Hmm. Then how does pipe avoid overwriting what it's already written at the 
in endpoint, or reading twice the same data from the out endpoint?

Amicalement,
--
Albert.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/