Re: [Xenomai-help] Communication between RT and non-RT thread

[Anders Blomdell <anders.blomdell@domain.hid>]

On 07/07/2011 09:31 AM, Richard Cochran wrote:
> On Wed, Jul 06, 2011 at 02:19:47PM +0200, Gilles Chanteperdrix wrote:
>> On 07/06/2011 01:42 PM, Andrey Nechypurenko wrote:
>>>
>>> What makes me worry here is the IPC abbreviation - I have just one
>>> process with multiple threads. So would not real IPC mechanism be the
>>> overkill in this scenario? Or am I just misinterpret what IPC means
>>> here?
>
> ...
>
>>
>> I am talking about the ring buffer thing with head and tail pointers
>> where each thread (consumer, producer), moves only one pointer. I would
>> call this a "lockless fifo", though I do not know what the official name
>> is, but you get the idea. Again, you can send pointers through an IPC
>> instead of sending the data themselves, and you will benefit from the
>> fact that the two threads are running in the same memory space.
>
> In Andrey's case, I would simply use a ring buffer (fifo) shared
> between one RT and one non-RT thread. No locking is needed, and it is
> easy to implement. You don't need a library for that.
If you want to do lockless passing of data, make sure that you have read 
and understood linux/Documentation/memory-barriers.txt

/Anders


-- 
Anders Blomdell                  Email: anders.blomdell@domain.hid
Department of Automatic Control
Lund University                  Phone:    +46 46 222 4625
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