Re: map-par slower than map

[Keith Wright]

Zelphir Kaltstahl <zelphirkaltstahl@posteo.de> writes:

> Of course,if you have global state and do not have a synchronization
> construct for accessing the hash table, I would expect things to
> go wrong at some point, with non-reproducible results.

Indeed.

> I do not think that futures are to blame here,
> or parallel map in that case.

Are futures to blame?  Do you blame the plus sign for
this wrong equation:  4+5=20?
My teachers blamed me for that sort of thing.

> With a synchronization construct, some kind of mutex,
> your bottle neck might just become that mutex.

But why make it parallel at all?  Unless you have some serious
parallel hardware you will just be wasting time in the scheduler
when you could be computing the answer.

In other news --- there are many kinds of people on this mailing
list.  I wonder what percentage are the kind that needs page-long
disjunctive normal form expressions in their mail boxes?

Not me.

   -- Keith

PS: For page-long boolean expression, they are nice.  But why?