Re: [Xenomai] xenomai-3.0-rc5 : binding named semaphores from external process

[Philippe Gerum <rpm@xenomai.org>]

On 07/30/2015 04:28 PM, Frederik Bayart wrote:

> I found already that 'select' on  socket(PF_UNIX, SOCK_STREAM, 0)  causes Interrupted system call (errno 4).
> If I replace 'select' with '__real_select' the problem seems to be solved, and the select timeout works.
> But the select doesn't seem to react on connect. I'm looking at the problem.
> 

It all depends on the flags passed to xeno-config (*): if --posix or
--rtdm is given (alone, or along with --native, --alchemy or whatever
other non-POSIX API), then POSIX calls will be wrapped to the
Xenomai/cobalt counterparts, in which case select() would call the
Xenomai implementation for instance.

If neither --posix nor --rtdm are given, then no wrapping takes place,
and select() will call the regular linux implementation.

If __real_select() works successfully in your app and differently than
select(), then wrapping is in effect, and this means that your file
descriptors are plain regular ones, obtained by standard linux syscalls
(__real_open, __real_socket), not by Xenomai syscalls (open, socket).

You may want to check for a mismatch due to POSIX symbol wrapping in
your app.

(*)
http://www.xenomai.org/documentation/xenomai-3/html/man1/xeno-config/index.html

-- 
Philippe.