IPC::PubSub3pm

    # A new message bus with the DBM::Deep backend
    # (Other possible backends include Memcached and PlainHash)
    my $bus = IPC::PubSub->new(DBM_Deep => '/tmp/pubsub.db');
    # A channel is any arbitrary string
    my $channel = '#perl6';
    # Register a new publisher (you can publish to multiple channels)
    my $pub = $bus->new_publisher("#perl6", "#moose");
    # Publish a message (may be a complex object) to those channels
    $pub->msg("This is a message");
    # Register a new subscriber (you can subscribe to multiple channels)
    my $sub = $bus->new_subscriber("#moose");
    # Publish an object to channels
    $pub->msg("This is another message");
    # Set all subsequent messages from this publisher to expire in 30 seconds
    $pub->expiry(30);
    $pub->msg("This message will go away in 30 seconds");
    # Simple get: Returns the messages sent since the previous get,
    # but only for the first channel.
    my @msgs = $sub->get;
    # Simple get, with an explicit channel key (must be among the ones
    # it initially subscribed to)
    my @moose_msgs = $sub->get("#moose");
    # Complex get: Returns a hash reference from channels to array
    # references of [timestamp, message].
    my $hash_ref = $sub->get_all;
    # Changing the list of channels we subscribe to
    $sub->subscribe('some-other-channel');
    $sub->unsubscribe('some-other-channel');
    # Changing the list of channels we publish to
    $pub->publish('some-other-channel');
    $pub->unpublish('some-other-channel');
    # Listing and checking if we are in a channel
    my @sub_channels = $sub->channels;
    my @pub_channels = $pub->channels;
    print "Sub is in #moose" if $sub->channels->{'#moose'};
    print "Pub is in #moose" if $pub->channels->{'#moose'};
    # Raw cache manipulation APIs (not advised; use ->modify instead)
    $bus->lock('channel');
    $bus->unlock('channel');
    my @timed_msgs = $bus->fetch('key1', 'key2', 'key3');
    $bus->store('key', 'value', time, 30);
    # Atomic updating of cache content; $_ is stored back on the
    # end of the callback.
    my $rv = $bus->modify('key' => sub { delete $_->{foo} });
    # Shorthand for $bus->modify('key' => sub { $_ = 'val' });
    $bus->modify('key' => 'val');
    # Shorthand for $bus->modify('key' => sub { $_ });
    $bus->modify('key');
    # Disconnect the backend connection explicitly
    $bus->disconnect;