On 14-11-2012 00:38, Andrei Alexandrescu wrote:
On 11/13/12 3:28 PM, Alex Rønne Petersen wrote:
On 13-11-2012 23:33, Andrei Alexandrescu wrote:
shared int x;
...
x = 4;

You'll need to use x.store(4) instead.

Is that meant to be an atomic store, or just a regular, but explicit,
store?

Atomic and sequentially consistent.


Andrei

OK, but then we have the problem I presented in the OP: This only works for certain types, on certain architectures, for certain processors, ...

So, we could limit shared load/store to only work on certain types and require all architectures that D compilers target to provide those. *But* this means that shared on any non-primitive types becomes essentially useless and will in 99% of cases just be casted away. On the other hand, if we make it implementation-defined, people end up writing highly unportable code. So, (unless anyone can come up with better alternatives), I think guaranteeing atomic load/store for a certain set of types is the most sensible way forward.

FWIW, these are the types and type categories I'd expect shared load/store to work on, on any architecture:

* ubyte, byte
* ushort, short
* uint, int
* ulong, long
* float, double
* pointers
* slices
* references
* function pointers
* delegates

--
Alex Rønne Petersen
a...@lycus.org
http://lycus.org

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