Something needs to happen with shared, and soon.

[Sean Kelly]

On Nov 15, 2012, at 3:05 PM, David Nadlinger <see at klickverbot.at> wrote:

> On Thursday, 15 November 2012 at 22:57:54 UTC, Andrei Alexandrescu wrote:
>> On 11/15/12 1:29 PM, David Nadlinger wrote:
>>> On Wednesday, 14 November 2012 at 17:54:16 UTC, Andrei Alexandrescu wrote:
>>>> That is correct. My point is that compiler implementers would follow
>>>> some specification. That specification would contain informationt hat
>>>> atomicLoad and atomicStore must have special properties that put them
>>>> apart from any other functions.
>>> 
>>> What are these special properties? Sorry, it seems like we are talking
>>> past each other…
>> 
>> For example you can't hoist a memory operation before a shared load or after a shared store.
> 
> Well, to be picky, that depends on what kind of memory operation you mean – moving non-volatile loads/stores across volatile ones is typically considered acceptable.

Usually not, really.  Like if you implement a mutex, you don't want non-volatile operations to be hoisted above the mutex acquire or sunk below the mutex release.  However, it's safe to move additional operations into the block where the mutex is held.