[ECOS] cyg_io_write

[Bob Koninckx]

Gary Thomas wrote:
> 
> On 28-Jun-00 Dave Airlie wrote:
> >
> > Can I call cyg_io_write from with a cyg_io_write? as in my app calls a
> > virtual cyg_io_write which then calls a cyg_io_write on a real serial
> > port... does this sound like something I really shouldn't be doing, it
> > doesn't seem to work, but the problems I've been having I would be loathe
> > to blame eCos before asking :-)
> >
> 
> I don't see any reason why it wouldn't work.  This function should be
> reentrant as well as serially reusable.


Make sure you never lock an already locked mutex. I remember spending
quite some time searching for a deadlock caused by this .... (I am not
sure it will happen in your case though)

Might be an idea do modify the cyg_mutex_t behaviour in such a way that
a call to cyg_mutexc_lock doesnt do anything if it is called from the
thread that already owns the lock. Similar to what "How are they called
again ??" does with their CRITICAL_SECTION objects. Cygnus folks ??

Regards,
Bob

-- 
-----------------------------------------------------------------------
 ir. Bob Koninckx
 Katholieke Universiteit Leuven       
 Division Production Engineering,     tel.  +32 16 322535
 Machine Design and Automation        fax.  +32 16 322987
 Celestijnenlaan 300B                 bob.koninckx@mech.kuleuven.ac.be
 B-3001 Leuven Belgium
 http://www.mech.kuleuven.ac.be/pma.html
-----------------------------------------------------------------------