Le 4 oct. 09 à 09:35, Thiago Macieira a écrit :

> Em Sábado 3. Outubro 2009, às 17.13.48, você escreveu:
>> Can I use QAtomicInt as "an Int with basic operations being atomic":
>> like getting, setting its value. Returning it from a function.
>> If not, when and how can I use it.
>
> int is already atomic in those operations.
>
> QAtomicInt introduces new atomic operations: fetch-and-add, test-and- 
> set and
> fetch-and-set. As for the memory ordering semantics, you had better  
> read a
> book.

But native set and get operations do not ensure cache consistency  
among your processors (you are just guaranteed that, as long as your  
data are correctly aligned, you'll never read a partial result from  
another thread) while atomic fetch-and-add, test-and-set and fetch-and- 
set use a memory barrier (AFAIK, atomic integers are useless without  
memory barrier).
-- 
Florent Bruneau



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