IO::Socket::Async is async, but not parallel

asyc-io-golf.pl6

#!/usr/bin/env perl6

# start this and then run e.g. ab -n 100 -c 25 http://127.0.0.1:6060
# you can also try by hand with telnet or so

my $h = '0.0.0.0';
my $p = 6060;
say "starting tcp server on $h:$p";
my $server-socket = IO::Socket::Async.listen($h, $p);
my $done = Promise.new();
my $srv-tap = $server-socket.tap( -> $client-socket {
    say "accepted connection in thread {$*THREAD.id}";
    $client-socket.Supply(:bin).tap( -> $input {
        say "input, handled in thread {$*THREAD.id}";
        # XXX do something with it
    },
    done => {
        say "connection lost";
    });
});

await $done;