From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 3 Nov 2014 16:22:37 -0600 From: "Steve M. Robbins" Message-ID: <20141103222237.GC15262@sumost.ca> References: <94331816.zv1NYeHro4@riemann> <20141031200007.GC378@sumost.ca> <5454ADDF.4040604@xenomai.org> <6071747.2uXMl1ZSO0@riemann> <54573A6D.1030201@xenomai.org> <20141103155947.GA15262@sumost.ca> <5457AD81.7090200@xenomai.org> <20141103183747.GB15262@sumost.ca> <5457DF1C.4060209@xenomai.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5457DF1C.4060209@xenomai.org> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Message Pipe services behaviour List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philippe Gerum Cc: Xenomai@xenomai.org On Mon, Nov 03, 2014 at 09:01:32PM +0100, Philippe Gerum wrote: > On 11/03/2014 07:37 PM, Steve M. Robbins wrote: > > On Mon, Nov 03, 2014 at 05:29:53PM +0100, Philippe Gerum wrote: > > > >> Just to make sure we are on the same page, as Dietmar mentioned in an > >> earlier mail, read() as implemented by the rt-pipe driver only returns > >> _one_ message at a time, although > 1 could be pending. One has to > >> iterate over a read() loop using a non-blocking fd on the /dev/rtp > >> device to get them all. > > > > Aha! Thanks (and to Dietmar). I completely missed this fact. I'll > > go re-write the read as a loop and see if it works better. I should read > > until the read() returns 0 (bytes read)? > > > > Until you get -1 with errno == EWOULDBLOCK. Zero would rather mean that > the other end of pipe has been disconnected, just like with a regular FIFO. Yes, that seems to work. The loop is reading about 2 messages on average as expected and no more filling up the heap. Thanks! -Steve -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 173 bytes Desc: Digital signature URL: