Re: About task-safeness

[Jeffrey Carter <spam.jrcarter.not@spam.not.acm.org>]

On 02/03/2011 04:22 AM, AdaMagica wrote:
>
> You mean C.1(11-12):
> (11) It is recommended that intrinsic subprograms be provided for
> convenient access to any machine
> operations that provide special capabilities or efficiency and that
> are not otherwise available through the
> language constructs. Examples of such instructions include:
> (12) � Atomic read-modify-write operations � e.g., test and set,
> compare and swap, decrement and test,
> enqueue/dequeue.
>
> But N := N + 1; is not such an operation even if N is atomic. An
> implementation would have to provide something like a CAS operation.

Those are examples of such operations, which will differ from machine to 
machine. If a machine offers an atomic increment operation, a compiler 
implementing Annex C should provide a subprogram to use it.

-- 
Jeff Carter
"How'd you like to hide the egg and gurgitate
a few saucers of mocha java?"
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101