atomic support for RTEMS Uniprocessor - AVR libc atomic block API

[Gedare Bloom]

We can probably add something like this over the atomic
implementation. This kind of interface would make for  user-friendly
atomic operations. I think it could be added as something to be done
with the ongoing atomic support project.

On Tue, Feb 12, 2013 at 11:25 AM, Ralf Kirchner
<ralf.kirchner at embedded-brains.de> wrote:
> What i like especially about the AVR implementation is:
>
> 1. There are different modes for invoking an atomic block
> (ATOMIC_RESTORATE, ATOMIC_FORCEON, ...)
>
> 2. You don't need an ATOMIC_START and ATOMIC_END macro. You simply write
> something like:
> ATOMIC_BLOCK(ATOMIC_RESTORATE)
> {
>   ctr_copy = ctr;
> }
>
> 3. Even nesting atomic blocks is possible.
>
>         Ralf Kirchner
>
> Am 11.02.2013 15:02, schrieb Gedare Bloom:
>> That is interesting and could be a way to address atomic support for
>> some of the uniprocessors. It looks like the basic idea is the same as
>> I sketched, to disable/enable interrupts around the operation. As
>> mentioned, we do not know if this is going to be safe in all
>> situations, e.g. if the atomic operations are used somewhere that
>> interrupts cannot safely be preempted. I don't know if such a
>> situation is a realistic one to worry about.
>>
>> -Gedare
>>
>> On Mon, Feb 11, 2013 at 3:39 AM, Ralf Kirchner
>> <ralf.kirchner at embedded-brains.de> wrote:
>>> Possibly a little off topic and more over a little late,
>>> But did you have a look at the atomic block implementation in AVR libc?
>>> I think they have quite a nice API.
>>> You can find it documented here:
>>> http://www.nongnu.org/avr-libc/user-manual/group__util__atomic.html
>>> and the source code is here:
>>> http://www.nongnu.org/avr-libc/user-manual/atomic_8h_source.html
>>>
>>> Kind Regards
>>> --
>>> --------------------------------------------
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>>>
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>
>
> --
> --------------------------------------------
> Embedded Brains GmbH
> Ralf Kirchner          Dornierstr. 4
> D-82178 Puchheim       Germany
> email: ralf.kirchner at embedded-brains.de
> Phone: +49-89-18 94 741-17
> Fax:   +49-89-18 94 741-08
>
> Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG.