[Edinburgh-pm] parallel semantics in perl

[Nick]

On 13/12/10 20:15, Wim Vanderbauwhede wrote:
> I'm looking into a way to run Perl on a manycore or multiprocessor
> system without visible threads or forks.

Are you interested in syntax or implementation?  I'm guessing the former.

Anyway, Google finds this - I've not read this in detail, but it may be
relevant.  Perhaps you've already read it.

http://www.dagolden.com/index.php/935/parallel-map-with-paralleliterator/


It works like this.

 use Parallel::Iterator qw<iterate_as_array>;

 my @result = iterate_as_array( $worker_sub, @list );


Presumably it could also easily work like this (using a (&) subroutine
prototype, i.e. sub iterate_as_array(&@) { ... } ):

 my @result = iterate_as_array { stuff_here($_) } @list;

Or even, with a bit of Devel::Declare'ation, and dropping the assignment to
@result, you *might* be able to:

 use Parallel qw<map>;

 for_each my $i (@list) :par {
     stuff_here($i);
 }

Where for_each is still ultimately despatched to a function.

Unfortunately I believe Devel::Declare has a performance penalty, as well as
being bleeding edge and a bit complicated.

N