Re: [Xenomai-help] shm_open, ftruncate

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Lionel Perrin wrote:
 > 
 > >  > - Will this shared memory be accessible to non rt-task ?
 > >  > - What's the simplest way to share information with a non rt-task ?
 > >
 > > Shared memory are also accessible to non-rt tasks. Since user-space
 > > realtime and non-realtime threads from the same process reside in the
 > > same address space, the simplest way to share information from rt to
 > > non-rt tasks is to create them as threads of the same process.
 > >   
 > Ok, but I figure out that it's possible to share memory between 
 > processes ? (rt and non rt?)
 > For the moment, i focus on sharing between two rt tasks, but in vain :(
 > I still have a ftruncate error (EBADF) when i launch two rt processes...
 > I explain :
 > I've tried the attached program. I've added a sleep(1) between mmap and 
 > munmap. I launch this appli twice with
 >  >> shm_test &
 >  >> shm_test &
 > For the second one, I got "ftruncate: Invalid argument". Am I the only 
 > one to have this problem ?

No, these errors were due to a few fixes in trunk that had not been
backported to the 2.1 branch. It should now be fixed in the repository.

-- 


					    Gilles Chanteperdrix.