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simple binary semaphore + priority inheritance



Joel Sherrill wrote:
>
> That combination never really worked.  The create let it slip through 
> and treated it as simple with priority -- no inheritance. Inheritance 
> needs the mutex to be allocated and deallocated by the same thread.  
> That is in conflict with the requirement that a simple binary 
> semaphore can be used for condition synchronization from an interrrupt.
>
> Hope that is clear.
>
It is - but IMHO this should be mentioned in the documentation.
I didn't find any hint that priority inheritance for simple binary
semaphores is illegal but maybe I missed somehing.

T.
>
> --joel
>
>> On Oct 17, 2009 5:11 PM, "Till Straumann" <strauman at slac.stanford.edu 
>> <mailto:strauman at slac.stanford.edu>> wrote:
>>
>> I see that on the HEAD simple binary semaphores no
>> longer are allowed to have the RTEMS_INHERIT_PRIORITY
>> (nor the RTEMS_PRIORITY_CEILING) attribute.
>>
>> What is the reason for this change? I suspect this
>> will break quite a few applications.
>>
>> -- Till
>>