[concurrency-interest] AtomicReference weakCompareAndSet"Mayfailspuriously"?

David Holmes dcholmes at optusnet.com.au
Sun May 28 20:11:24 EDT 2006


Bill,

I must be missing something.

> > But isn't the existence of those edges the only thing that
> > distinguishes
> > volatile semantics from non-volatile (barring the 64-bit atomicity
> > issue)?
>
> Nope. Volatile semantics also mean that it it is a synchronization
> action,
> that there is a total order over synchronization actions, and that
> each volatile
> read sees the value of the write to that variable that occurred most
> recently in that total order.

But isn't that all just a long-winded way of saything that it creates
happens-before edges?

Otherwise, what on earth does "creates happens-before edges" mean?

Cheers,
David



More information about the Concurrency-interest mailing list