Re: [ECOS] Update on the availability of socketpair()?

[Andrew Lunn <andrew at lunn dot ch>]

On Wed, Jan 21, 2004 at 03:28:20PM -0600, Philip.Fleege@gd-ais.com wrote:
> Hi All-
> 

> I read in an earlier posting;
> http://sources.redhat.com/ml/ecos-discuss/2003-07/msg00485.html that
> the function: socketpair() was intentionally left out of the 2.0
> release.  But that it could (and therefore might) be added.  Is
> there any short term (or long term) plan to add this call?

Not that i know of. Nobody has contributed patchs as far as i know.

> Just as is described in the reference above, I'm porting some unix
> code that uses a "tickle" pipe to wakeup a thread blocking on
> select().  And yes, I could use a 'localhost' socket.  However, I am
> advocating that socketpair() be added since it makes the application
> code so simple and elegant.

If you want it, then i suggest you implement it (or contract somebody
to do it for you). It should not be too difficult. 

> Finally, if there is an effort to add this to eCos, what is the
> chances that it could be kept in without having to have all the
> network code; or it be a "configurable" item.  I guess what I'm
> really asking is what are the chances that a pipe() system call be
> added.  Our embedded application will actually be using serial
> lines...but we use the network during development (to fake out
> devices) so our final software will not have a network stack (thus
> no socketpair() when we remove network support).

The current socket interface has a plugin architecture. There is a
generic socket layer which different stacks register there
implementations of socket functions to. You should implement your code
as a little stack which registers itself and only implements AF_LOCAL
socketpair(). You will need to extend the socket interface a little
since it currently does not have socketpair(), but that should not be
too hard.  With this architecture it should be easy to make it run
with and without the AF_INET TCP/IP stack.

        Andrew

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