From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <43B3FABA.4050903@domain.hid> Date: Thu, 29 Dec 2005 16:03:22 +0100 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Xenomai-core] autostart timer, rt_timer_start/stop References: <43B3EAFA.2050906@domain.hid> In-Reply-To: <43B3EAFA.2050906@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig7839872C66485920C4D55547" Sender: jan.kiszka@domain.hid List-Id: "Xenomai life and development \(bug reports, patches, discussions\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Kisdaroczi Cc: xenomai@xenomai.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig7839872C66485920C4D55547 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Stefan Kisdaroczi wrote: > Hi, > > cant the timer be started by default ? > > The current state (2.0.1) seems to lead to the following scenario: > 1) Every app calls rt_timer_start() > 2) If you call rt_timer_stop you can hurt other rt-apps, so dont > call it > 3) As some apps dont stop the timer, check in 1) if its already running > > I think most apps do not care in which mode the timer is running if it is already, > and just go on, of course you can stop and restart the timer if its a wrong state, > but you do not know if you hurt others. > > Now, as i read in the other thread that the periodic timer support isnt configured by default, > why not start the oneshot timer automatic ? > > Like this, a 'normal' app doesnt need to fiddle with the timer and > an app that really cares can still call rt_timer_inquire,_stop,_start. > Yea, that's good that someone else brings this topic up again! :) I've been pointing on this several times, but as we did not come to a conclusion how to handle the system timer in a consistent way across all skins, no one (me included...) came up with a fix of this issue so far. The thing is that most skins start the timer during module init via some parameter (nowadays also as a kernel boot option for compiled-in skins). As far as I remember, only the native and the RTAI compat skin do their own dance - the latter one has to remain compatible, ok, but the former one should be allowed to perform smarter. Ok, to be more concrete: autostarting the one-shot time in the absence of periodic mode is certainly worth considering. For the other cases and as sysfs is no option on 2.4 kernels, what about adding a /proc-exported control mechanism for the timer mode (and period) to either the HAL or the nucleus? Additionally, we could provide some CONFIG_xyz to set the default mode during compile time. Ceterum censeo rt_timer_start/stop esse delendam. ;) Jan --------------enig7839872C66485920C4D55547 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDs/q6niDOoMHTA+kRAvN1AJ4vLpJUEQZZmSqnyu6xAq7FoMyeXwCfeIAc 2H6PPwD807FK2g/uz/rY55U= =iTUU -----END PGP SIGNATURE----- --------------enig7839872C66485920C4D55547--