oz_(un)protect() API unsafe

[Denys Duchier]

David Hopwood <david.nospam.hopwood at blueyonder.co.uk> writes:

> It needs to be an atomic counter, I think.

there is no need.  every operation that creates/touches/references Oz data must
be executed synchronously by the emulator.  no other pthread is allowed to
execute such operations.  in order to remove this limitation, a mutex would be
needed to protect every heap access and that would be prohibitively expensive.

Cheers,

--Denys