From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4ACDE467.9020202@domain.hid> Date: Thu, 08 Oct 2009 15:08:55 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <0000ACAE.4ACDAF68@domain.hid> <4ACDA23D.4000507@domain.hid> <4ACDB034.7060801@domain.hid> <4ACDB1F8.6060305@domain.hid> <4ACDBBF8.6090007@domain.hid> <4ACDD8B6.4020902@domain.hid> In-Reply-To: <4ACDD8B6.4020902@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Re : rt_printf with daemonized task List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gilles Chanteperdrix Cc: "xenomai@xenomai.org" , "oliver.schlenker@domain.hid" Gilles Chanteperdrix wrote: > Jan Kiszka wrote: >> Gilles Chanteperdrix wrote: >>> Jan Kiszka wrote: >>>> Gilles Chanteperdrix wrote: >>>>> oliver.schlenker@domain.hid wrote: >>>>>>>> int main( int arc, char *argv[] ) { int i; >>>>>>>> >>>>>>>> rt_print_auto_init(1); >>>>>>>> >>>>>>>> rt_printf("--------------- TEST RT-PRINTF 1 ------------\n"); >>>>>>>> >>>>>>>> sleep(1); >>>>>>>> >>>>>>>> daemon(0,0); >>>>>>>> >>>>>>>> rt_print_auto_init(1); >>>>>> Ok, understood, at least for the scenario where the rt_print feature >>>>>> is initialised befor the fork/daemon call. What I don't understand >>>>>> is, why it does not work if the rt_print feature is initialised after >>>>>> the fork / daemon. >>>>> From the way I understand your code, you never tried to initialize the >>>>> rt_print feature only after the fork, your code initializes it both >>>>> before and after. >>>>> >>>> There are two initializations: The base init done via __rt_print_init on >>>> library loading and the one to be done per-thread via rt_print_init (or >>>> on first rt_printf). That printer thread is initialized via the former >>>> one. On fork, we do not need to re-run the full __rt_print_init >>>> (variables and resources are cloned on fork), we just need to spawn >>>> another printer thread. >>> Unless I am wrong, rtdk also maintains a list of the thread buffers >>> which need to be polled. After the fork, this list will be intact, but >>> the threads to which belong the buffers will no longer exist. So, IMO, >>> the fork handler should also free all these buffers and reset the list >>> to the empty state. >> Famous last words: That should work without tweaking. A print_buffer >> only contains data references, nothing that points to some uncloned thread. > > Ok. But you walk the list of print_buffers every time, and these > print_buffers remain allocated in the child process. So, that is a kind > of memory leak. Hmm, right. They should be freed in the child right after forking. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux