[En-Nut-Discussion] Feature Request 1572837: mutex API nesting level info

[Alain M.]

Hi,

I was checking with a friend who has a better understanding of those 
matters:

Neither os us have eve known of a mutex that can be locled more than 
once on the same thread just because the thread lock on the first atempt 
if it is not available.

Also never heard of a Semaphore that is not thread-aware.

I was wrong about using Semaphores as counters, this is a non-standard use.

The "normal" way of controling re-entrancy is to have a mutex + a 
counter, no standard simpler way. In Nut, NutEnterCritical() can be 
lighter, but it may depend on the application.

My vote: use only what is standard and well known to every one. (This 
has already been Nut's way for long...)

Alain

Przemek Rudy escreveu:
> Matthias Ringwald pisze:
>> ...
>> semaphore. Even more, a semaphore initialized to one cannot be aquired  
>> a second time, even if its by the same thread. that's why the  
>> recursive mutex is good for, it allows repeated locking by the  same  
>> thread.
> Yes, that is the reason...
> 
> So I see just up to two questions that need to be answered:
> 1. If to follow posix or not:
> [yes] - do not change anything.
> [no]:
> 2. if the returned mutex counter is useful:
> [yes] - then change mutex code
> [no]  - do not change anything.
> _______________________________________________
> http://lists.egnite.de/mailman/listinfo/en-nut-discussion
> 
>