my $request_q;
my $response_q;

sub testc {
    my $t0 = time;
    $request_q  = Thread::Queue->new();
    $response_q = Thread::Queue->new();

    my $merge_thread = threads->create(\&outputc);

    my @worker_threads;
    for (1..$threads) {
       push @worker_threads, async {
          while ( my $job = $request_q->dequeue() ) {
             $response_q->enqueue([ $job->[0], worka($job->[1]) ]);
          }
       };
    }

    inputc();

    $request_q->end();
    $_->join() for @worker_threads;

    $response_q->end();
    $merge_thread->join();

    printf STDERR "testc done in %0.02f seconds\n",time - $t0;
}

sub inputc {
    my $id = -1;
    foreach my $a(1..$iterations) {
        my @chunk = ();
        foreach my $b(1..$chunksize) {
            my %adata = %data;
            $adata{'.'} = $a * $b;
            push(@chunk,\%adata);
        }

        $request_q->enqueue([ ++$id, \@chunk ]);
    }
}

sub outputc {
    my $next_id = 0;
    my %cache;

    open(my $fh,'>',$aoutput);
    while( my $job = $response_q->dequeue() ) {
        if ($job->[0] != $next_id) {
           $cache{$job->[0]} = $job;
           next;
        }

        do {
            foreach my $data(@{ $job->[1] }) {
                foreach my $key(sort keys %$data) {
                    print {$fh} $$data{$key};
                }
                print {$fh} "\n";
            }

            $job = delete($cache{++$next_id});
        } while $job;
    }

    close($fh);
}