Re: hook question

[Mike Pall <mikelu-0610@...>]

Hi,

David Jones wrote:
> This assumes that updates to each of hookmask and hook will take  
> place atomically.  There's no guarantee of that.  On some  
> architectures an update of hook may consist of two writes (to two  
> halves of a 64-bit quantity say) and a re-ordered write to hookmask  
> may appear in between them.

Please. If updates to a pointer sized quantity (32 bit on 32 bit
systems, 64 bit on 64 bit systems) are non-atomic, fire the CPU
designer team. AFAIK none of the 64 bit multi-core machines on
the market do this.

> I can see that the code has been written with great care, but that  
> doesn't make it correct.

Make a test case, find a machine where it verifiably fails (build
one, if necessary) and submit a patch. Being a pragmatic, I'll
type Ctrl-D now and continue with more interesting things.

Bye,
     Mike