#! perl -slw
use strict;
use threads;
use threads::shared;
use Thread::Queue;
use Time::HiRes qw[ time sleep ];

my $dqd :shared = 0;
my $nqd :shared = 0;
my $Q = new Thread::Queue;

my $start = time;

async {
    while( $Q->dequeue ) {
       ++$dqd;
    }
}->detach;

async {
    for ( 1 .. 1e6 ) {
        $Q->enqueue( $_ );
        ++$nqd;
    }
}->detach;

while( sleep 0.1 and $dqd < 1e6 ) {
    my $e = time - $start;
    printf STDERR "\rn;%7d (%.3f/s) d:%7d (%.3f/s)",
        $nqd, $nqd / $e, $dqd, $dqd / $e;
}