Re: [9fans] 9P2000 and p9p

["Bruce Ellis" <bruce.ellis@gmail.com>]

can i say that EOD is useless on synthesized files.  may be good
on readonly stuff.  i hate the extra read of 0 but get over it.

as presto once said "are you just whining or preposing a solution?".

brucee

On 4/11/07, Russ Cox <rsc@swtch.com> wrote:
> > There is no correlation between read and write ops executed on different
> > machines to the same file server, wherever it is running on.
>
> This is not true.
>
> Suppose two programs running on two different machines
> are communicating directly but also using a shared file server.
>
> Then program A could write something to a file, tell program B
> there was new data in the file, and program B could read it.
> Repeat.  You get the same write, read, write, read sequence
> I gave before, but without any central kernel that knows enough
> to second-guess the EOD tag on the first read response -- the
> reads happen using one machine, the writes using another.
>
> You are proposing a clumsy fix to a problem that you haven't
> actually demonstrated to exist.  The extra read is just not
> costly enough in practice to justify the extra complexity.
>
> You are already doing Twalk Topen Tread Tclunk.  A second
> Tread won't hurt very much.  If you really care about minimizing
> the number of requests, you'd do better to have a single "events"
> file that got opened once and then polled (with blocking reads)
> to get information out of the device.
>
> Russ
>
>