[EMAIL PROTECTED] wrote: >> -----Ursprüngliche Nachricht----- >> Von: Gilles Chanteperdrix [mailto:[EMAIL PROTECTED] >> Gesendet: Donnerstag, 16. Oktober 2008 11:48 >> An: Wildenburg, Roderik RAEK3 MRA >> Cc: [email protected] >> Betreff: Re: [Xenomai-help] how to build a Xenomai posix library ? >> >> [EMAIL PROTECTED] wrote: >>> I did so and called, within the library, every >> posix_rt-function with >>> the prefix __wrap_ : e.g. __wrap_shm_open then I compiled my >>> application, which does not use any Xenomai-function, and linked it >>> with pthread_rt an rt (-lpthread_rt -lrt) and my new Xenomai-library >>> (linking without any wrapping defined). Linking and >> compiling did not >>> produce any error. But, when I call a function in my library, which >>> in turn calls __wrap_shm_open, then shm_open fails. When I link my >>> application with wrapping (as provided by the XENO_CONFIG-script) >>> then everything is fine. Do you have an explanation for >> this behavior >>> or even better a solution ? >> __wrap_shm_open only works if you have the CONFIG_XENO_OPT_POSIX_SHM >> option enabled. Is it enabled? > > yes it is : > CONFIG_XENO_OPT_POSIX_SHM=y > otherwise, I think, my application linked with wrappings defined wouldn´t > work ? But it does. > >> Note that xenomai posix skin shm support >> is mainly useful for sharing memory between kernel and >> user-space. > O.k., I just want to share SHM between applications. What SHM construct > should I use instead ? > >> If it is enabled, then please tell us what is the value of errno when >> __wrap_shm_open fails. >> > > shm_open fails. errno=2 > shm_open fails : : No such file or directory > > I don´t know what this should mean ??
Well, it means that the shared memory does not exist. > I call shm_open in the following way : > #define LOGSHMNAME "/var/logshm" > oflags=O_RDWR; > *shmfd = shm_open(LOGSHMNAME, oflags, 0); a shm name should contain one slash at the beginning and no other slash, for best portability. If you want to create a shared memory, you should pass the O_CREAT flag. This is all documented here: http://www.xenomai.org/documentation/trunk/html/api/group__posix__shm.html#gf765a0fa9152fbf874436c966f3af7ba -- Gilles. _______________________________________________ Xenomai-help mailing list [email protected] https://mail.gna.org/listinfo/xenomai-help
