[interfacekit] Re: BLocker's implementation issue(?)

"burton666@xxxxxxxxx" <burton666@xxxxxxxxx> wrote:
> I was looking through BLocker's source code, and I noticed this:
> 
> int32 oldBenaphoreCount = atomic_add(&fBenaphoreCount, 1);
> if (oldBenaphoreCount > 0) {
>  etc. etc.
> 
> Should this be 
> if (atomic_add(&fBenaphoreCount, 1))
>   etc. etc. ?
> 
> Since the value returned from atomic_add could change before 
> executing the if.

No no, atomic_add() returns the old value of fBenaphoreCount and at the 
same time, atomically sets it to another value (adds one).
The "oldBenaphoreCount" variable won't be changed anymore - it reflects 
the state at the time atomic_add() was executed, and we are only 
interested in that state (if it has changed in the meantime, the other 
thread will block, but we don't have to).

Adios...
   Axel.

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