Re: [PATCH] Futex Asynchronous Interface

[H. Peter Anvin]

Followup to:  <[e-mail]>
By author:    Linus Torvalds <[e-mail]>
In newsgroup: linux.dev.kernel
> 
> But what would you _do_ with them? What would be the advantage as compared
> to the current situation?
> 
> Now, to configure a device, you get a fd to the device the same way you
> get a fd _anyway_ - with "socket()".
> 
> And anybody who says that "socket()" is utterly unnatural to the UNIX way
> is quite far out to lunch. It may be unnatural to the Plan-9 way of
> "everything is a namespace", but that was never the UNIX way. The UNIX way
> is "everything is a file descriptor or a process", but that was never
> about namespaces.
> 
> Yes, some old-timers could argue that original UNIX didn't have sockets,
> and that the BSD interface is ugly and an abomination and that it _should_
> have been a namespace thing, but that argument falls flat on its face when
> you realize that the "pipe()" system call _was_ in original UNIX, and has
> all the same issues.
> 

The biggest problem with the socket API is that it makes it impossible
to use in a shell script context or other context where it isn't
practical to operate on binary data.  The second-biggest problem with
the API is that it at least historically makes it basically impossible
to write address-family-independent code... something like "telnet"
shouldn't need to know if it's operating over TCP on IPv4, TCP on
IPv6, SPX on IPX...; it should be able to resolve a string to a name and
then create a connection, and the address family stuff should be
encasulated in the library.

The first problem a namespace-like solution would deal with... then
one could open /dev/sock/stream/ipv4/206.189.222.9/23 using a normal
open() call.  The second is to resolve "poetry.vogon.net","telnet" to
the above string, but that's a user-space issue.

At least it would be nice if open() on a Unix domain socket would
connect to that socket.

	-hpa

-- 
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