APIs: POSIX versus Classic

Chris Johns chrisj at rtems.org
Fri Aug 16 01:30:21 UTC 2013

Joel Sherrill wrote:
> On 08/05/2013 02:43 AM, Sebastian Huber wrote:
>> Hello,
>> the only reason why the POSIX API is optional is that you can save
>> some code
>> and data space in applications that don't need it. It helps also to
>> reduce the
>> code size to be reviewed.
> But underneath they are both instances of SuperCore Thread with
> different attributes set. There is some extra data to track the POSIX
> API features like signal sets, etc. and the minimum code added is
> mostly initialization.

We need to add keys and a condition variable to the classic API because 
we need these for SMP. This means the differences between the 2 APIs is 
closing all the time.

We should aim for a zero cost approach where ever possible.


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