Bad multithreaded sort function.

ThreadSort.pl6

#!/usr/bin/env perl6
use v6;

sub sort-promise ($c) {
      my @same;
      earliest $c {
         more $c { push @same, $c.receive }
         done $c { return }
      }
      my @chans = Channel.new xx 2;
      my @promises = map -> $cc { start { sort-promise($cc) } }, @chans;
      1 while do earliest $c {
        more * {
          given $_ <=> @same[0] {
            when Same { push @same, $_ }
            when Less { @chans[0].send( $_ ) }
            when More { @chans[1].send( $_ ) }
          }
          True;
        }
        done * { False }
      };
      .close for @chans;
      |@promises[0].result, |@same, |@promises[1].result;
}

my $sort_chan = Channel.new;
my $sort_promise = start { sort-promise($sort_chan) };
$sort_chan.send($_) for (^10).pick(*);
$sort_chan.close;
$sort_promise.result.say;