#! perl -slw
use strict;
use Data::Dump qw[ pp ];
use threads;
use threads::shared;
use thread::queue;

our $THREADS ||= 5;

--$THREADS;

my @Qins = map Thread::Queue->new(), 0 .. $THREADS;
my $Qout = Thread::Queue->new;

sub worker {
    my $tid = threads->tid;
    warn "$tid: starting\n";
    my( $Qin, $Qout ) = @_;

    while( my $work = $Qin->dequeue ) {
        my %h = ( 'a'..'z' );
        $Qout->enqueue( \%h );
    }
    warn "$tid: ending\n";
}


my @threads = map threads->new( \&worker, $Qins[ $_ ], $Qout ), 0 .. $THREADS;

my $tOut = async{
    while( my $out = $Qout->dequeue ) {
        pp $out;
    }
    warn "output thread finished\n";
};

my $i = 0;
while( <> ) {
    $Qins[ $i ]->enqueue( $_ );
    $i %= $THREADS;
}
warn "Finished reading & queing file\n";

$_->enqueue( undef ) for @Qins;

$_->join for @threads;

$Qout->enqueue( undef );
$tOut->join;

warn "main finished\n";