oz_(un)protect() API unsafe

[Raphael Collet]

Denys, this is unclear to me, too.  Could you please explain the 
problem, and the proposed fix?

Thanks,
raph

Boriss Mejias wrote:
> Denys Duchier wrote:
>> Am I dreaming, or is the oz_(un)protect interface completely unsafe?  
>> If Oz
>> thread A protects T and then Oz thread B protects T too, the first one to
>> unprotect it will screw things up for the other one.  If you agree 
>> with my
>> interpretation, please let me know and I will fix it (fairly simple). 
>> If you do
>> not agree, please explain.
> 
> Sorry for the stupid question but is the first time I hear about 
> oz_(un)protect and I couldn't find anything in the documentation. 
> Looking at the code I just found code related to garbage collection, so 
> I cannot object your proposal, but could you explain the fix?
>