Nulls

Remi Forax forax at univ-mlv.fr
Fri Sep 21 11:17:12 PDT 2012


On 09/21/2012 07:41 PM, Brian Goetz wrote:
>> I only bring up the others because so many people are worried that the
>> extra Optional object will never ever be optimized away and will slow
>> everything down.
>
> The "extra object" argument here is mostly a red herring.  There is so 
> much work going on to set up the iterators and such, that one more 
> object *per pipeline* is noise.  An object per element, sure, that's a 
> big deal.  But to set up a pipeline you're probably already allocating 
> a few objects per pipeline stage -- the Op object, an Iterator or a 
> Sink, etc.

Objects per pipeline is noise until you set up the pipeline in a loop.

BTW, you can use the same object for the Iterator and the Op, may be not 
a good design but it will reduce the number of objects creation.

>
> If you're doing a parallel decomposition you're creating log(n) 
> FJtasks and such.  Again, another object at the end is noise.
>

Rémi



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