func main() {
	//  Socket to send messages on
	sender, _ := zmq.NewSocket(zmq.PUSH)
	defer sender.Close()
	sender.Bind("tcp://*:5557")

	//  Socket to send start of batch message on
	sink, _ := zmq.NewSocket(zmq.PUSH)
	defer sink.Close()
	sink.Connect("tcp://localhost:5558")

	fmt.Print("Press Enter when the workers are ready: ")
	var line string
	fmt.Scanln(&line)
	fmt.Println("Sending tasks to workers...")

	//  The first message is "0" and signals start of batch
	sink.Send("0", 0)

	//  Initialize random number generator
	rand.Seed(time.Now().UnixNano())

	//  Send 100 tasks
	total_msec := 0
	for task_nbr := 0; task_nbr < 100; task_nbr++ {
		//  Random workload from 1 to 100msecs
		workload := rand.Intn(100) + 1
		total_msec += workload
		s := fmt.Sprintf("%d", workload)
		sender.Send(s, 0)
	}
	fmt.Println("Total expected cost:", time.Duration(total_msec)*time.Millisecond)
	time.Sleep(time.Second) //  Give 0MQ time to deliver

}

func main() {
	//  Socket to receive messages on
	receiver, _ := zmq.NewSocket(zmq.PULL)
	defer receiver.Close()
	receiver.Connect("tcp://localhost:5557")

	//  Socket to send messages to
	sender, _ := zmq.NewSocket(zmq.PUSH)
	defer sender.Close()
	sender.Connect("tcp://localhost:5558")

	//  Process tasks forever
	for {
		s, _ := receiver.Recv(0)

		//  Simple progress indicator for the viewer
		fmt.Print(s + ".")

		//  Do the work
		msec, _ := strconv.Atoi(s)
		time.Sleep(time.Duration(msec) * time.Millisecond)

		//  Send results to sink
		sender.Send("", 0)
	}
}

func main() {
	lbbroker := &lbbroker_t{}
	lbbroker.frontend, _ = zmq.NewSocket(zmq.ROUTER)
	lbbroker.backend, _ = zmq.NewSocket(zmq.ROUTER)
	defer lbbroker.frontend.Close()
	defer lbbroker.backend.Close()
	lbbroker.frontend.Bind("ipc://frontend.ipc")
	lbbroker.backend.Bind("ipc://backend.ipc")

	for client_nbr := 0; client_nbr < NBR_CLIENTS; client_nbr++ {
		go client_task()
	}
	for worker_nbr := 0; worker_nbr < NBR_WORKERS; worker_nbr++ {
		go worker_task()
	}

	//  Queue of available workers
	lbbroker.workers = make([]string, 0, 10)

	//  Prepare reactor and fire it up
	lbbroker.reactor = zmq.NewReactor()
	lbbroker.reactor.AddSocket(lbbroker.backend, zmq.POLLIN,
		func(e zmq.State) error { return handle_backend(lbbroker) })
	lbbroker.reactor.Run(-1)
}

func main() {
	//  Socket to receive messages on
	receiver, _ := zmq.NewSocket(zmq.PULL)
	defer receiver.Close()
	receiver.Bind("tcp://*:5558")

	//  Socket for worker control
	controller, _ := zmq.NewSocket(zmq.PUB)
	defer controller.Close()
	controller.Bind("tcp://*:5559")

	//  Wait for start of batch
	receiver.Recv(0)

	//  Start our clock now
	start_time := time.Now()

	//  Process 100 confirmations
	for task_nbr := 0; task_nbr < 100; task_nbr++ {
		receiver.Recv(0)
		if task_nbr%10 == 0 {
			fmt.Print(":")
		} else {
			fmt.Print(".")
		}
	}
	fmt.Println("\nTotal elapsed time:", time.Since(start_time))

	//  Send kill signal to workers
	controller.Send("KILL", 0)

	//  Finished
	time.Sleep(time.Second) //  Give 0MQ time to deliver
}

func main() {
	//  Prepare our context and sockets
	publisher, _ := zmq.NewSocket(zmq.PUB)
	publisher.Bind("tcp://*:5557")

	sequence := int64(0)
	rand.Seed(time.Now().UnixNano())

	//  Start state manager and wait for synchronization signal
	updates, _ := zmq.NewSocket(zmq.PAIR)
	updates.Bind("inproc://pipe")
	go state_manager()
	updates.RecvMessage(0) // "READY"

	for {
		//  Distribute as key-value message
		sequence++
		kvmsg := kvsimple.NewKvmsg(sequence)
		kvmsg.SetKey(fmt.Sprint(rand.Intn(10000)))
		kvmsg.SetBody(fmt.Sprint(rand.Intn(1000000)))
		if kvmsg.Send(publisher) != nil {
			break
		}
		if kvmsg.Send(updates) != nil {
			break
		}
	}
	fmt.Printf("Interrupted\n%d messages out\n", sequence)
}

func New(primary bool, local, remote string) (bstar *Bstar, err error) {

	bstar = &Bstar{}

	//  Initialize the Binary Star
	bstar.Reactor = zmq.NewReactor()
	if primary {
		bstar.state = state_PRIMARY
	} else {
		bstar.state = state_BACKUP
	}

	//  Create publisher for state going to peer
	bstar.statepub, err = zmq.NewSocket(zmq.PUB)
	bstar.statepub.Bind(local)

	//  Create subscriber for state coming from peer
	bstar.statesub, err = zmq.NewSocket(zmq.SUB)
	bstar.statesub.SetSubscribe("")
	bstar.statesub.Connect(remote)

	//  Set-up basic reactor events
	bstar.Reactor.AddChannelTime(time.Tick(bstar_HEARTBEAT), 1,
		func(i interface{}) error { return bstar.send_state() })
	bstar.Reactor.AddSocket(bstar.statesub, zmq.POLLIN,
		func(e zmq.State) error { return bstar.recv_state() })

	return
}

func main() {

	srv := &clonesrv_t{
		port:  5556,
		kvmap: make(map[string]*kvmsg.Kvmsg),
	}

	//  Set up our clone server sockets
	srv.snapshot, _ = zmq.NewSocket(zmq.ROUTER)
	srv.snapshot.Bind(fmt.Sprint("tcp://*:", srv.port))
	srv.publisher, _ = zmq.NewSocket(zmq.PUB)
	srv.publisher.Bind(fmt.Sprint("tcp://*:", srv.port+1))
	srv.collector, _ = zmq.NewSocket(zmq.PULL)
	srv.collector.Bind(fmt.Sprint("tcp://*:", srv.port+2))

	//  Register our handlers with reactor
	reactor := zmq.NewReactor()
	reactor.AddSocket(srv.snapshot, zmq.POLLIN,
		func(e zmq.State) error { return snapshots(srv) })
	reactor.AddSocket(srv.collector, zmq.POLLIN,
		func(e zmq.State) error { return collector(srv) })
	reactor.AddChannelTime(time.Tick(1000*time.Millisecond), 1,
		func(v interface{}) error { return flush_ttl(srv) })

	log.Println(reactor.Run(100 * time.Millisecond)) // precision: .1 seconds
}

func main() {

	//  Connect to task ventilator
	receiver, _ := zmq.NewSocket(zmq.PULL)
	defer receiver.Close()
	receiver.Connect("tcp://localhost:5557")

	//  Connect to weather server
	subscriber, _ := zmq.NewSocket(zmq.SUB)
	defer subscriber.Close()
	subscriber.Connect("tcp://localhost:5556")
	subscriber.SetSubscribe("10001 ")

	//  Initialize poll set
	poller := zmq.NewPoller()
	poller.Add(receiver, zmq.POLLIN)
	poller.Add(subscriber, zmq.POLLIN)
	//  Process messages from both sockets
	for {
		sockets, _ := poller.Poll(-1)
		for _, socket := range sockets {
			switch s := socket.Socket; s {
			case receiver:
				task, _ := s.Recv(0)
				//  Process task
				fmt.Println("Got task:", task)
			case subscriber:
				update, _ := s.Recv(0)
				//  Process weather update
				fmt.Println("Got weather update:", update)
			}
		}
	}
}

func main() {
	var configfile string
	flag.StringVar(&configfile, "config", "./broker.json", "Broker JSON config file")
	flag.Parse()

	file, err := ioutil.ReadFile(configfile)
	if err != nil {
		panic("could not read config file: " + err.Error())
	}

	f := ConfigData{}
	err = json.Unmarshal(file, &f)

	pubsocket, _ := zmq.NewSocket(zmq.PUB)
	repsocket, _ := zmq.NewSocket(zmq.REP)
	defer pubsocket.Close()
	defer repsocket.Close()
	pubsocket.Bind(f.PubSocket)
	repsocket.Bind(f.RepSocket)

	var e envelope
	for {
		msg, _ := repsocket.Recv(0)
		json.Unmarshal([]byte(msg), &e)
		pubsocket.Send(e.Address, zmq.SNDMORE)
		pubsocket.Send(e.Content, 0)
		repsocket.Send("published", 0)
	}
}

func main() {
	frontend, _ := zmq.NewSocket(zmq.ROUTER)
	backend, _ := zmq.NewSocket(zmq.ROUTER)
	defer frontend.Close()
	defer backend.Close()
	frontend.Bind("tcp://*:5555") //  For clients
	backend.Bind("tcp://*:5556")  //  For workers

	//  Queue of available workers
	workers := make([]string, 0)

	poller1 := zmq.NewPoller()
	poller1.Add(backend, zmq.POLLIN)
	poller2 := zmq.NewPoller()
	poller2.Add(backend, zmq.POLLIN)
	poller2.Add(frontend, zmq.POLLIN)

	//  The body of this example is exactly the same as lbbroker2.
LOOP:
	for {
		//  Poll frontend only if we have available workers
		var sockets []zmq.Polled
		var err error
		if len(workers) > 0 {
			sockets, err = poller2.Poll(-1)
		} else {
			sockets, err = poller1.Poll(-1)
		}
		if err != nil {
			break //  Interrupted
		}
		for _, socket := range sockets {
			switch s := socket.Socket; s {
			case backend: //  Handle worker activity on backend
				//  Use worker identity for load-balancing
				msg, err := s.RecvMessage(0)
				if err != nil {
					break LOOP //  Interrupted
				}
				var identity string
				identity, msg = unwrap(msg)
				workers = append(workers, identity)

				//  Forward message to client if it's not a READY
				if msg[0] != WORKER_READY {
					frontend.SendMessage(msg)
				}

			case frontend:
				//  Get client request, route to first available worker
				msg, err := s.RecvMessage(0)
				if err == nil {
					backend.SendMessage(workers[0], "", msg)
					workers = workers[1:]
				}
			}
		}
	}
}

func BrokerTask() {
	//  Prepare our sockets
	frontend, _ := zmq.NewSocket(zmq.DEALER)
	frontend.Bind("tcp://*:5555")
	backend, _ := zmq.NewSocket(zmq.DEALER)
	backend.Bind("tcp://*:5556")
	zmq.Proxy(frontend, backend, nil)
}

func main() {
	log.SetLevel(log.InfoLevel)
	var configfile string
	flag.StringVar(&configfile, "config", "./broker.json", "Broker JSON config file")
	flag.Parse()

	file, err := ioutil.ReadFile(configfile)
	if err != nil {
		log.Fatal("could not read config file: " + err.Error())
	}

	f := ConfigData{}
	err = json.Unmarshal(file, &f)
	if err != nil {
		log.Fatal("could not parse config file: " + err.Error())
	}
	var c config
	err = envconfig.Process("broker", &c)
	if err != nil {
		log.Fatal(err.Error())
	}

	// defaults to INFO
	if c.LogLevel == "DEBUG" {
		log.SetLevel(log.DebugLevel)
	}
	if c.LogLevel == "WARN" {
		log.SetLevel(log.WarnLevel)
	}
	if c.LogLevel == "ERROR" {
		log.SetLevel(log.ErrorLevel)
	}
	if c.LogLevel == "FATAL" {
		log.SetLevel(log.FatalLevel)
	}

	pubsocket, _ := zmq.NewSocket(zmq.PUB)
	repsocket, _ := zmq.NewSocket(zmq.REP)
	defer pubsocket.Close()
	defer repsocket.Close()
	pubsocket.Bind(f.PubSocket)
	repsocket.Bind(f.RepSocket)

	log.Info("listening on ZMQ sockets")

	var e envelope
	for {
		msg, _ := repsocket.Recv(0)
		json.Unmarshal([]byte(msg), &e)
		pubsocket.Send(e.Address, zmq.SNDMORE)
		pubsocket.Send(e.Content, 0)
		repsocket.Send("published", 0)
		log.Debug("published message")
	}
}

func main() {
	frontend, _ := zmq.NewSocket(zmq.SUB)
	frontend.Bind("tcp://*:5557")
	backend, _ := zmq.NewSocket(zmq.XPUB)
	backend.Bind("tcp://*:5558")

	//  Subscribe to every single topic from publisher
	frontend.SetSubscribe("")

	//  Store last instance of each topic in a cache
	cache := make(map[string]string)

	//  We route topic updates from frontend to backend, and
	//  we handle subscriptions by sending whatever we cached,
	//  if anything:
	poller := zmq.NewPoller()
	poller.Add(frontend, zmq.POLLIN)
	poller.Add(backend, zmq.POLLIN)
LOOP:
	for {
		polled, err := poller.Poll(1000 * time.Millisecond)
		if err != nil {
			break //  Interrupted
		}

		for _, item := range polled {
			switch socket := item.Socket; socket {
			case frontend:
				//  Any new topic data we cache and then forward
				msg, err := frontend.RecvMessage(0)
				if err != nil {
					break LOOP
				}
				cache[msg[0]] = msg[1]
				backend.SendMessage(msg)
			case backend:
				//  When we get a new subscription we pull data from the cache:
				msg, err := backend.RecvMessage(0)
				if err != nil {
					break LOOP
				}
				frame := msg[0]
				//  Event is one byte 0=unsub or 1=sub, followed by topic
				if frame[0] == 1 {
					topic := frame[1:]
					fmt.Println("Sending cached topic", topic)
					previous, ok := cache[topic]
					if ok {
						backend.SendMessage(topic, previous)
					}
				}
			}
		}
	}
}

func TestKvmsg(t *testing.T) {

	//  Prepare our context and sockets
	output, err := zmq.NewSocket(zmq.DEALER)
	if err != nil {
		t.Error(err)
	}

	err = output.Bind("ipc://kvmsg_selftest.ipc")
	if err != nil {
		t.Error(err)
	}

	input, err := zmq.NewSocket(zmq.DEALER)
	if err != nil {
		t.Error(err)
	}

	err = input.Connect("ipc://kvmsg_selftest.ipc")
	if err != nil {
		t.Error(err)
	}

	kvmap := make(map[string]*Kvmsg)

	//  Test send and receive of simple message
	kvmsg := NewKvmsg(1)
	kvmsg.SetKey("key")
	kvmsg.SetBody("body")
	kvmsg.Dump()
	err = kvmsg.Send(output)

	kvmsg.Store(kvmap)
	if err != nil {
		t.Error(err)
	}

	kvmsg, err = RecvKvmsg(input)
	if err != nil {
		t.Error(err)
	}
	kvmsg.Dump()
	key, err := kvmsg.GetKey()
	if err != nil {
		t.Error(err)
	}
	if key != "key" {
		t.Error("Expected \"key\", got \"" + key + "\"")
	}
	kvmsg.Store(kvmap)

	input.Close()
	output.Close()
	os.Remove("kvmsg_selftest.ipc")
}

func agent_new() (agent *agent_t) {
	agent = &agent_t{
		servers: make(map[string]*server_t),
		actives: make([]*server_t, 0),
		request: make([]string, 0),
		reply:   make([]string, 0),
	}
	agent.pipe, _ = zmq.NewSocket(zmq.PAIR)
	agent.pipe.Connect("inproc://pipe")
	agent.router, _ = zmq.NewSocket(zmq.ROUTER)
	return
}

func main() {
	snapshot, _ := zmq.NewSocket(zmq.DEALER)
	snapshot.Connect("tcp://localhost:5556")

	subscriber, _ := zmq.NewSocket(zmq.SUB)
	subscriber.SetSubscribe("")
	subscriber.Connect("tcp://localhost:5557")

	time.Sleep(time.Second) // or messages between snapshot and next are lost

	kvmap := make(map[string]*kvsimple.Kvmsg)

	//  Get state snapshot
	sequence := int64(0)
	snapshot.SendMessage("ICANHAZ?")
	for {
		kvmsg, err := kvsimple.RecvKvmsg(snapshot)
		if err != nil {
			fmt.Println(err)
			break //  Interrupted
		}
		if key, _ := kvmsg.GetKey(); key == "KTHXBAI" {
			sequence, _ = kvmsg.GetSequence()
			fmt.Printf("Received snapshot=%d\n", sequence)
			break //  Done
		}
		kvmsg.Store(kvmap)
	}
	snapshot.Close()

	first := true
	//  Now apply pending updates, discard out-of-sequence messages
	for {
		kvmsg, err := kvsimple.RecvKvmsg(subscriber)
		if err != nil {
			fmt.Println(err)
			break //  Interrupted
		}
		if seq, _ := kvmsg.GetSequence(); seq > sequence {
			sequence, _ = kvmsg.GetSequence()
			kvmsg.Store(kvmap)
			if first {
				// Show what the first regular update is after the snapshot,
				// to see if we missed updates.
				first = false
				fmt.Println("Next:", sequence)
			}
		}
	}
}

func server_new(address string, port int, subtree string) (server *server_t) {
	server = &server_t{}

	fmt.Printf("I: adding server %s:%d...\n", address, port)
	server.address = address
	server.port = port

	server.snapshot, _ = zmq.NewSocket(zmq.DEALER)
	server.snapshot.Connect(fmt.Sprintf("%s:%d", address, port))
	server.subscriber, _ = zmq.NewSocket(zmq.SUB)
	server.subscriber.Connect(fmt.Sprintf("%s:%d", address, port+1))
	server.subscriber.SetSubscribe(subtree)
	return
}

func main() {
	//  First argument is this broker's name
	//  Other arguments are our peers' names
	//
	if len(os.Args) < 2 {
		fmt.Println("syntax: peering1 me {you}...")
		os.Exit(1)
	}
	self := os.Args[1]
	fmt.Printf("I: preparing broker at %s...\n", self)
	rand.Seed(time.Now().UnixNano())

	//  Bind state backend to endpoint
	statebe, _ := zmq.NewSocket(zmq.PUB)
	defer statebe.Close()
	statebe.Bind("ipc://" + self + "-state.ipc")

	//  Connect statefe to all peers
	statefe, _ := zmq.NewSocket(zmq.SUB)
	defer statefe.Close()
	statefe.SetSubscribe("")
	for _, peer := range os.Args[2:] {
		fmt.Printf("I: connecting to state backend at '%s'\n", peer)
		statefe.Connect("ipc://" + peer + "-state.ipc")
	}

	//  The main loop sends out status messages to peers, and collects
	//  status messages back from peers. The zmq_poll timeout defines
	//  our own heartbeat:

	poller := zmq.NewPoller()
	poller.Add(statefe, zmq.POLLIN)
	for {
		//  Poll for activity, or 1 second timeout
		sockets, err := poller.Poll(time.Second)
		if err != nil {
			break
		}

		//  Handle incoming status messages
		if len(sockets) == 1 {
			msg, _ := statefe.RecvMessage(0)
			peer_name := msg[0]
			available := msg[1]
			fmt.Printf("%s - %s workers free\n", peer_name, available)
		} else {
			statebe.SendMessage(self, rand.Intn(10))
		}
	}
}

func main() {
	//  This is where the weather server sits
	frontend, _ := zmq.NewSocket(zmq.XSUB)
	defer frontend.Close()
	frontend.Connect("tcp://192.168.55.210:5556")

	//  This is our public endpoint for subscribers
	backend, _ := zmq.NewSocket(zmq.XPUB)
	defer backend.Close()
	backend.Bind("tcp://10.1.1.0:8100")

	//  Run the proxy until the user interrupts us
	err := zmq.Proxy(frontend, backend, nil)
	log.Fatalln("Proxy interrupted:", err)
}

func main() {
	worker, _ := zmq.NewSocket(zmq.REQ)
	defer worker.Close()

	//  Set random identity to make tracing easier
	rand.Seed(time.Now().UnixNano())
	identity := fmt.Sprintf("%04X-%04X", rand.Intn(0x10000), rand.Intn(0x10000))
	worker.SetIdentity(identity)
	worker.Connect("tcp://localhost:5556")

	//  Tell broker we're ready for work
	fmt.Printf("I: (%s) worker ready\n", identity)
	worker.Send(WORKER_READY, 0)

	for cycles := 0; true; {
		msg, err := worker.RecvMessage(0)
		if err != nil {
			break //  Interrupted
		}

		//  Simulate various problems, after a few cycles
		cycles++
		if cycles > 3 && rand.Intn(5) == 0 {
			fmt.Printf("I: (%s) simulating a crash\n", identity)
			break
		} else if cycles > 3 && rand.Intn(5) == 0 {
			fmt.Printf("I: (%s) simulating CPU overload\n", identity)
			time.Sleep(3 * time.Second)
		}

		fmt.Printf("I: (%s) normal reply\n", identity)
		time.Sleep(time.Second) //  Do some heavy work
		worker.SendMessage(msg)
	}
}