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

sub worker {
    my $tid = threads->tid;
    print "Thread: $tid started";
    my $Q = shift;
    while( my $workitem = $Q->dequeue ) {
        print "Thread: $tid processing workitem $workitem";
        sleep $workitem;
    }
    print "Thread: $tid ended";
}

our $WORKERS //= 10;
our $ITEMS   //= 1000;
our $MAXWORK //= 2;

my $Q = new Thread::Queue;
my @workers = map threads->create( \&worker, $Q ), 1 .. $WORKERS;

for ( 1 .. $ITEMS ) {
    sleep 1 while $Q->pending > $WORKERS;
    $Q->enqueue( rand( $MAXWORK ) );
    print "main Q'd workitem $_";
}
print "Main: telling threads to die";
$Q->enqueue( (undef) x $WORKERS );

print "Main waiting for threads to die";
$_->join for @workers;