From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <50C8B445.2080609@xenomai.org> Date: Wed, 12 Dec 2012 17:43:49 +0100 From: Philippe Gerum MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Timer support in user-space List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: dave.joynson@alstom.com Cc: xenomai@xenomai.org On 12/12/2012 05:26 PM, dave.joynson@alstom.com wrote: > Hi, > I have recently started to use Xenomai on Raspberry Pi. My experience with > Linux Kernel building etc. is zero so I downloaded the pre-built image > from powet.eu. I have successfully created a cross compile environment to > create user-space applications using the Posix skin. While tracking down > some mode changes I came across the limitation of Posix skin Timers in > that the timer expiry creates a signal which causes a mode switch. > I have considered creating an application layer timer module using a pool > of threads that use nanosleep and a callback function on expiry. Careful > management of these threads using a custom timer API could fulfill my > requirements. > While exploring the documentation for alternatives, I noticed that the > RTDM Driver Development API provides access to native timers that would > seem to perform the functionality that I need, On trying to use them in a > user-space application, however, it seems that they may only be used in > kernel-space. This leads me to the following question: > > Is the documentation incorrect for rtdm_timer_init() when it says > it may be used in user-space tasks? Yes. This is likely a copy&paste leftover. -- Philippe.