On Sun, 6 May 2007, Alan Cox wrote:
> > However, whatever policy the buffer uses, the fundamental point it's that
> > when I flush the input buffer I should be sure that each byte read
> > after the flush is *new* (current) data and not old one. This because
>
> Define "new" and "old" in this case. I don't believe you can give a
> precise definition or that such a thing is physically possible.
One can come close. It would make sense to say that after a flush,
subsequent reads should retrieve _contiguous_ bytes from the input stream.
In other words, rule out the possibility that the read would get bytes
1-10 (from some buffer somewhere) followed by bytes 30-60 (because bytes
11-29 were dropped by the flush). By contrast, it would be permissible
for the read to obtain bytes 20-60, even though 20-29 may have been
entered the input stream before the flush occurred.
> The hardware itself has buffers at both ends of the link, there may be
> buffers in modems, muxes and the like as well. We can certainly flush
> input buffers in the kernel but it isn't clear we can always do so at the
> hardware level, let alone at the remote end or buffers on devices on the
> link.
This is of course the fly in the ointment.
Alan Stern
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
