C11 Re: [PATCH 3/6] termios: Use C11 mutex for input/output

[Sebastian Huber]

On 15/12/16 23:34, Chris Johns wrote:
> On 15/12/2016 18:02, Sebastian Huber wrote:
>> On 14/12/16 22:15, Chris Johns wrote:
>>> On 15/12/2016 00:39, Sebastian Huber wrote:
[...]
>>> Would the "tiny" footprint be smaller if all internal services
>>> including compiler thread support are made C11? Could this actually be
>>> done? Parts of POSIX has been creeping in over time so the position is
>>> a little confused at the moment. I am not sure about a bits and pieces
>>> approach, maybe a full switch is made.
>>
>> Yes, the footprint would be smaller. If we provide self-contained
>> threads, then the footprint would be much smaller, e.g. no object
>> administration, no heap.
>
> Great. This is a powerful reason to look at moving in this direction 
> and removing the remaining POSIX usage in libstdthreads.
>
> A brief audit of rtems.git shows the change is possible with less than 
> 30 Classic task creates and a similar number of semaphore creates so a 
> full change look reachable which is nice.
>
> Should we look at moving all internal services to C11 and standardise 
> it? I think there is value in doing this. It can be a post 4.12 branch 
> activity. 

In contrast to the C11 mutexes, I don't see a real value in moving from 
Classic API tasks to C11 threads. The Classic API you have more control 
over task attributes, modes, priority, stack size, etc.

I created two tickets:

https://devel.rtems.org/ticket/2842
https://devel.rtems.org/ticket/2843

Joel, Gedare, what is your opinion with respect to C11 mutexes?

-- 
Sebastian Huber, embedded brains GmbH

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