Need simple parallelism example in Perl 6 - parallel-processing

Question

I am trying to learn Perl 6 and parallelism/concurrency at the same time.
For a simple learning exercise, I have a folder of 550 '.htm' files and I want the total sum of lines of code among all of them. So far, I have this:
use v6;
my $start_time = now;
my $exception;
my $total_lines = 0;
my #files = "c:/testdir".IO.dir(test => / '.' htm $/);
for #files -> $file {
$total_lines += $file.lines.elems;
CATCH {
default { $exception = $_; } #some of the files error out for malformed utf-8
}
}
say $total_lines;
say now - $start_time;
That gives a sum of 577,449 in approximately 3 seconds.
How would I rewrite that to take advantage of Perl 6 parallelism ideas? I realize the time saved won't be much but it will work as proof of concept.

Answer 1

Implementing Christoph's suggestion. The count is slightly higher than my original post because I'm now able to read in the malformed UTF-8 files using encode latin1.
use v6;
my $start_time = now;
my #files = "c:/iforms/live".IO.dir(test => / '.' htm $/);
my $total_lines = [+] #files.race.map(*.lines(:enc<latin1>).elems);
say $total_lines;
say now - $start_time;

Answer 2

use v6;
my $start_time = now;
my $exception;
my #lines;
my $total_lines = 0;
my #files = "c:/testdir".IO.dir(test => / '.' htm $/);
await do for #files -> $file {
start {
#lines.push( $file.lines.elems );
CATCH {
default { $exception = $_; } #some of the files error out for malformed utf-8
}
}
}
$total_lines = [+] #lines;
say $total_lines;
say now - $start_time;