From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Thu, 01 Mar 2007 12:22:34 +0100
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Subject: Re: [Xenomai-help] CAN rt_dev_recvfrom
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From: Roland Tollenaar <rwatollenaar@domain.hid>
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To: Wolfgang Grandegger <wg@domain.hid>, Xenomai-help@domain.hid

Hi Wolfgang,

>> Can this be confirmed or is rt_dev_recvfrom() behaving incorrectly in 
>> my case?
> 
> rt_dev_recvfrom() reads message frames (one at a time) from an internal 
> socket buffer (there is actually a kernel configuration option to 
> configure the size). If no messages are available, it will block by 
> default, but it can also be used in non-blocking mode by using the flag 
> MSG_DONTWAIT. It seems, that your application is trying to read messages 
> periodically in polling mode. Either you do reading and buffering in 
> your own thread as you suggested above or you use rt_dev_recvfrom() in 
> non-blocking mode.

Thanks for this. I have not tried it yet but I was looking for that flag 
in the hope that something like this would exist. I thought I had seen 
something like it but when I tried to locate it yesterday I failed. 
Don;t worry it is there, I just checked. Sorry.

Where can I find the buffer size option in the kernel config menu? What 
is the default size?

Thanks again.

Roland

> 
> Wolfgang.
> 
>