示例#1
0
文件: main.go 项目: mkrzewic/FairRoot
func main() {
	var iaddr string
	flag.StringVar(&iaddr, "iaddr", "tcp://localhost:5555", "input data port")

	var oaddr string
	flag.StringVar(&oaddr, "oaddr", "tcp://localhost:5556", "output data port")

	flag.Parse()

	isck, err := pull.NewSocket()
	if err != nil {
		log.Fatalf("error creating a nanomsg socket: %v\n", err)
	}
	defer isck.Close()

	isck.AddTransport(ipc.NewTransport())
	isck.AddTransport(tcp.NewTransport())

	osck, err := push.NewSocket()
	if err != nil {
		log.Fatalf("error creating output port: %v\n", err)
	}
	defer osck.Close()

	osck.AddTransport(ipc.NewTransport())
	osck.AddTransport(tcp.NewTransport())

	log.Printf("dialing %s ...\n", iaddr)
	err = isck.Dial(iaddr)
	if err != nil {
		log.Fatalf("error dialing: %v\n", err)
	}
	log.Printf("dialing %s ... [done]\n", iaddr)

	log.Printf("dialing %s ...\n", oaddr)
	err = osck.Dial(oaddr)
	if err != nil {
		log.Fatalf("error dialing: %v\n", err)
	}
	log.Printf("dialing %s ... [done]\n", oaddr)

	for {
		msg, err := isck.Recv()
		if err != nil {
			if err == io.EOF || err == mangos.ErrClosed {
				log.Printf("received EOF: %v\n", err)
				break
			}
			log.Fatalf("error receiving data: %v\n", err)
		}
		log.Printf("recv: %v\n", string(msg))

		omsg := bytes.Repeat(msg, 2)
		err = osck.Send(omsg)
		if err != nil {
			log.Fatalf("error sending data: %v\n", err)
		}
	}

}
示例#2
0
func TestSimpleCorrect(t *testing.T) {
	tx, e := pair.NewSocket()
	if e != nil {
		t.Fatalf("NewSocket: %v", e)
		return
	}
	rx, e := pair.NewSocket()
	if e != nil {
		t.Fatalf("NewSocket: %v", e)
		return
	}
	tx.AddTransport(tcp.NewTransport())
	rx.AddTransport(tcp.NewTransport())

	if e = rx.Listen(AddrTestTCP); e != nil {
		t.Fatalf("Listen: %v", e)
		return
	}
	if e = tx.Dial(AddrTestTCP); e != nil {
		t.Fatalf("Dial: %v", e)
		return
	}

	wg := &sync.WaitGroup{}
	wg.Add(2)
	go simpleSend(t, tx, wg)
	go simpleRecv(t, rx, wg)
	wg.Wait()
}
示例#3
0
func node0(url string) {
	var sock mangos.Socket
	var err error
	var msg []byte
	if sock, err = rep.NewSocket(); err != nil {
		die("can't get new rep socket: %s", err)
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Listen(url); err != nil {
		die("can't listen on rep socket: %s", err.Error())
	}
	for {
		// Could also use sock.RecvMsg to get header
		msg, err = sock.Recv()
		if string(msg) == "DATE" { // no need to terminate
			fmt.Println("NODE0: RECEIVED DATE REQUEST")
			d := date()
			fmt.Printf("NODE0: SENDING DATE %s\n", d)
			err = sock.Send([]byte(d))
			if err != nil {
				die("can't send reply: %s", err.Error())
			}
		}
	}
}
示例#4
0
func testDevLoop(t *testing.T, addr string) {
	s1, err := pair.NewSocket()
	if err != nil {
		t.Errorf("Failed to open S1: %v", err)
		return
	}
	defer s1.Close()
	s1.AddTransport(tcp.NewTransport())
	s1.AddTransport(inproc.NewTransport())
	s1.AddTransport(ipc.NewTransport())
	s1.AddTransport(tlstcp.NewTransport())
	s1.AddTransport(ws.NewTransport())
	s1.AddTransport(wss.NewTransport())

	options := make(map[string]interface{})
	if strings.HasPrefix(addr, "wss://") || strings.HasPrefix(addr, "tls+tcp://") {
		options[mangos.OptionTLSConfig] = srvCfg
	}

	if err := s1.ListenOptions(addr, options); err != nil {
		t.Errorf("Failed listening to %s: %v", addr, err)
		return
	}

	if err := mangos.Device(s1, s1); err != nil {
		t.Errorf("Device failed: %v", err)
		return
	}

	RunTests(t, addr, deviceCaseClient())
}
示例#5
0
func server(url string, nworkers int) {
	var sock mangos.Socket
	var err error
	var wg sync.WaitGroup

	rand.Seed(time.Now().UnixNano())

	if sock, err = rep.NewSocket(); err != nil {
		die("can't get new rep socket: %s", err)
	}
	if err = sock.SetOption(mangos.OptionRaw, true); err != nil {
		die("can't set raw mode: %s", err)
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Listen(url); err != nil {
		die("can't listen on rep socket: %s", err.Error())
	}
	wg.Add(nworkers)
	fmt.Printf("Starting %d workers\n", nworkers)
	for id := 0; id < nworkers; id++ {
		go func(id int) {
			defer wg.Done()
			serverWorker(sock, id)
		}(id)
	}
	wg.Wait()
}
示例#6
0
func newEvtChannel(addr string) (mangos.Socket, error) {
	socket, err := sub.NewSocket()
	if err != nil {
		return nil, err
	}

	if err := socket.SetOption(mangos.OptionRecvDeadline, time.Second*120); err != nil {
		socket.Close()
		return nil, err
	}

	//socket.AddTransport(ipc.NewTransport())
	socket.AddTransport(tcp.NewTransport())
	if err := socket.Dial(addr); err != nil {
		socket.Close()
		return nil, err
	}

	err = socket.SetOption(mangos.OptionSubscribe, []byte(""))
	if err != nil {
		return nil, err
	}

	return socket, nil
}
示例#7
0
文件: main.go 项目: mkrzewic/FairRoot
func main() {
	var addr string
	flag.StringVar(&addr, "addr", "tcp://localhost:5555", "input data port")

	flag.Parse()

	sck, err := pull.NewSocket()
	if err != nil {
		log.Fatalf("error creating a nanomsg socket: %v\n", err)
	}
	defer sck.Close()

	sck.AddTransport(ipc.NewTransport())
	sck.AddTransport(tcp.NewTransport())

	log.Printf("dialing %s ...\n", addr)
	err = sck.Dial(addr)
	if err != nil {
		log.Fatalf("error dialing: %v\n", err)
	}
	log.Printf("dialing %s ... [done]\n", addr)

	for {
		msg, err := sck.Recv()
		if err != nil {
			if err == io.EOF || err == mangos.ErrClosed {
				log.Printf("received EOF: %v\n", err)
				break
			}
			log.Fatalf("error receiving from bus: %v\n", err)
		}
		log.Printf("recv: %v\n", string(msg))
	}

}
示例#8
0
func newCmdClient(addr string) (mangos.Socket, error) {
	socket, err := req.NewSocket()
	if err != nil {
		return nil, err
	}

	if err := socket.SetOption(mangos.OptionSendDeadline, time.Second*3); err != nil {
		socket.Close()
		return nil, err
	}

	if err := socket.SetOption(mangos.OptionRecvDeadline, time.Second*3); err != nil {
		socket.Close()
		return nil, err
	}

	//socket.AddTransport(ipc.NewTransport())
	socket.AddTransport(tcp.NewTransport())
	if err := socket.Dial(addr); err != nil {
		socket.Close()
		return nil, err
	}

	return socket, nil
}
示例#9
0
func client(url string, name string) {
	var sock mangos.Socket
	var err error
	var msg []byte

	if sock, err = respondent.NewSocket(); err != nil {
		die("can't get new respondent socket: %s", err.Error())
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Dial(url); err != nil {
		die("can't dial on respondent socket: %s", err.Error())
	}
	for {
		if msg, err = sock.Recv(); err != nil {
			die("Cannot recv: %s", err.Error())
		}
		fmt.Printf("CLIENT(%s): RECEIVED \"%s\" SURVEY REQUEST\n",
			name, string(msg))

		d := date()
		fmt.Printf("CLIENT(%s): SENDING DATE SURVEY RESPONSE\n", name)
		if err = sock.Send([]byte(d)); err != nil {
			die("Cannot send: %s", err.Error())
		}
	}
}
示例#10
0
文件: bus.go 项目: go-lsst/ncs
func newBusNode(addr string) (busNode, error) {
	var err error
	var node busNode

	sock, err := bus.NewSocket()
	if err != nil {
		return node, err
	}

	node.sock = sock
	node.sock.AddTransport(ipc.NewTransport())
	node.sock.AddTransport(tcp.NewTransport())

	err = node.sock.Listen("tcp://127.0.0.1:0")
	if err != nil {
		return node, err
	}

	err = node.sock.Dial(addr)
	if err != nil {
		return node, err
	}

	return node, err
}
示例#11
0
func server(url string) {
	var sock mangos.Socket
	var err error
	var msg []byte
	if sock, err = surveyor.NewSocket(); err != nil {
		die("can't get new surveyor socket: %s", err)
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Listen(url); err != nil {
		die("can't listen on surveyor socket: %s", err.Error())
	}
	err = sock.SetOption(mangos.OptionSurveyTime, time.Second/2)
	if err != nil {
		die("SetOption(): %s", err.Error())
	}
	for {
		time.Sleep(time.Second)
		fmt.Println("SERVER: SENDING DATE SURVEY REQUEST")
		if err = sock.Send([]byte("DATE")); err != nil {
			die("Failed sending survey: %s", err.Error())
		}
		for {
			if msg, err = sock.Recv(); err != nil {
				break
			}
			fmt.Printf("SERVER: RECEIVED \"%s\" SURVEY RESPONSE\n",
				string(msg))
		}
		fmt.Println("SERVER: SURVEY OVER")
	}
}
示例#12
0
func client(url string, name string) {
	var sock mangos.Socket
	var err error
	var msg []byte

	if sock, err = sub.NewSocket(); err != nil {
		die("can't get new sub socket: %s", err.Error())
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Dial(url); err != nil {
		die("can't dial on sub socket: %s", err.Error())
	}
	// Empty byte array effectively subscribes to everything
	err = sock.SetOption(mangos.OptionSubscribe, []byte(""))
	if err != nil {
		die("cannot subscribe: %s", err.Error())
	}
	for {
		if msg, err = sock.Recv(); err != nil {
			die("Cannot recv: %s", err.Error())
		}
		fmt.Printf("CLIENT(%s): RECEIVED %s\n", name, string(msg))
	}
}
示例#13
0
// NewDaemon creates and returns a new Daemon from the provided Config. An
// error is returned if the Daemon cannot be created.
func NewDaemon(config *Config) (*Daemon, error) {
	rep, err := rep.NewSocket()
	if err != nil {
		return nil, err
	}
	rep.AddTransport(tcp.NewTransport())
	return &Daemon{rep, nil, []*publisher{}, []*subscriber{}, config}, nil
}
示例#14
0
文件: all.go 项目: laszlo-kiss/mangos
// AddTransports adds all known transports to the given socket.
func AddTransports(sock mangos.Socket) {
	sock.AddTransport(tcp.NewTransport())
	sock.AddTransport(inproc.NewTransport())
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tlstcp.NewTransport())
	sock.AddTransport(ws.NewTransport())
	sock.AddTransport(wss.NewTransport())
}
示例#15
0
// NewClient creates and returns a new Client from the provided Benchmark
// configuration. It returns an error if the Benchmark is not valid or it
// can't communicate with any of the specified peers.
func NewClient(b *Benchmark) (*Client, error) {
	if err := b.validate(); err != nil {
		return nil, err
	}

	brokerd, err := req.NewSocket()
	if err != nil {
		return nil, err
	}

	brokerd.AddTransport(tcp.NewTransport())
	brokerd.SetOption(mangos.OptionSendDeadline, time.Duration(b.DaemonTimeout)*time.Second)
	brokerd.SetOption(mangos.OptionRecvDeadline, time.Duration(b.DaemonTimeout)*time.Second)

	if err := brokerd.Dial(fmt.Sprintf("tcp://%s", b.BrokerdHost)); err != nil {
		return nil, err
	}

	peerd := make(map[string]mangos.Socket, len(b.PeerHosts))
	for _, peer := range b.PeerHosts {
		s, err := req.NewSocket()
		if err != nil {
			return nil, err
		}

		s.AddTransport(tcp.NewTransport())
		s.SetOption(mangos.OptionSendDeadline, time.Duration(b.DaemonTimeout)*time.Second)
		s.SetOption(mangos.OptionRecvDeadline, time.Duration(b.DaemonTimeout)*time.Second)

		if err := s.Dial(fmt.Sprintf("tcp://%s", peer)); err != nil {
			return nil, err
		}

		peerd[peer] = s
	}

	return &Client{
		brokerd:   brokerd,
		peerd:     peerd,
		Benchmark: b,
	}, nil
}
示例#16
0
func newSocket() mangos.Socket {
	socket, err := pair.NewSocket()
	if err != nil {
		log.Fatalf("Node %s: Cannot create socket: %s\n", node, err.Error())
	}

	socket.AddTransport(ipc.NewTransport())
	socket.AddTransport(tcp.NewTransport())

	socket.SetOption(mangos.OptionRecvDeadline, 10*time.Second)
	return socket
}
示例#17
0
func testDevChain(t *testing.T, addr1 string, addr2 string, addr3 string) {
	// This tests using multiple devices across a few transports.
	// It looks like this:  addr1->addr2->addr3 <==> addr3->addr2->addr1
	var err error
	s := make([]mangos.Socket, 5)
	for i := 0; i < 5; i++ {
		if s[i], err = pair.NewSocket(); err != nil {
			t.Errorf("Failed to open S1_1: %v", err)
			return
		}
		defer s[i].Close()
		s[i].AddTransport(tcp.NewTransport())
		s[i].AddTransport(inproc.NewTransport())
		s[i].AddTransport(tlstcp.NewTransport())
		s[i].AddTransport(ipc.NewTransport())
		s[i].AddTransport(ws.NewTransport())
	}

	if err = s[0].Listen(addr1); err != nil {
		t.Errorf("s[0] Listen: %v", err)
		return
	}
	if err = s[1].Dial(addr2); err != nil {
		t.Errorf("s[1] Dial: %v", err)
		return
	}
	if err = s[2].Listen(addr2); err != nil {
		t.Errorf("s[2] Listen: %v", err)
		return
	}
	if err = s[3].Dial(addr3); err != nil {
		t.Errorf("s[3] Dial: %v", err)
		return
	}
	if err = s[4].Listen(addr3); err != nil {
		t.Errorf("s[4] Listen: %v", err)
		return
	}
	if err = mangos.Device(s[0], s[1]); err != nil {
		t.Errorf("s[0],s[1] Device: %v", err)
		return
	}
	if err = mangos.Device(s[2], s[3]); err != nil {
		t.Errorf("s[2],s[3] Device: %v", err)
		return
	}
	if err = mangos.Device(s[4], nil); err != nil {
		t.Errorf("s[4] Device: %v", err)
		return
	}
	RunTests(t, addr1, deviceCaseClient())
}
示例#18
0
func node0(url string) {
	var sock mangos.Socket
	var err error
	if sock, err = pair.NewSocket(); err != nil {
		die("can't get new pair socket: %s", err)
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Listen(url); err != nil {
		die("can't listen on pair socket: %s", err.Error())
	}
	sendRecv(sock, "node0")
}
示例#19
0
func starTestNewClient(t *testing.T, addr string, id int) *starTester {
	var err error
	bt := &starTester{id: id, rdoneq: make(chan bool), sdoneq: make(chan bool)}

	if bt.sock, err = star.NewSocket(); err != nil {
		t.Errorf("Failed getting client %d socket: %v", id, err)
		return nil
	}
	bt.sock.AddTransport(tcp.NewTransport())
	if err = bt.sock.Dial(addr); err != nil {
		t.Errorf("Failed client %d dialing: %v", id, err)
		bt.sock.Close()
		return nil
	}
	return bt
}
示例#20
0
文件: msgq.go 项目: ibmendoza/msgq
func newSocket(url, protocol string) (sock mangos.Socket, err error) {
	var str string

	switch protocol {
	case "bus":
		sock, err = bus.NewSocket()
		str = "bus.NewSocket: "
	case "pair":
		sock, err = pair.NewSocket()
		str = "pair.NewSocket: "
	case "push":
		sock, err = push.NewSocket()
		str = "push.NewSocket: "
	case "pull":
		sock, err = pull.NewSocket()
		str = "pull.NewSocket: "
	case "pub":
		sock, err = pub.NewSocket()
		str = "pub.NewSocket: "
	case "sub":
		sock, err = sub.NewSocket()
		str = "sub.NewSocket: "
	case "request":
		sock, err = req.NewSocket()
		str = "request.NewSocket: "
	case "reply":
		sock, err = rep.NewSocket()
		str = "reply.NewSocket: "
	case "surveyor":
		sock, err = surveyor.NewSocket()
		str = "surveyor.NewSocket: "
	case "respondent":
		sock, err = respondent.NewSocket()
		str = "respondent.NewSocket: "
	}

	if err != nil {
		s := fmt.Sprintf(str+" %s", err)
		return nil, errors.New(s)
	}

	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())

	return sock, nil
}
示例#21
0
文件: bus.go 项目: go-lsst/ncs
func (b *sysbus) init() error {
	sck, err := bus.NewSocket()
	if err != nil {
		b.Errorf("error creating a nanomsg socket: %v\n", err)
		return err
	}

	b.sck = sck
	b.sck.AddTransport(ipc.NewTransport())
	b.sck.AddTransport(tcp.NewTransport())

	err = b.sck.Listen(BusAddr)
	if err != nil {
		return err
	}

	return err
}
示例#22
0
func node1(url string, msg string) {
	var sock mangos.Socket
	var err error

	if sock, err = push.NewSocket(); err != nil {
		die("can't get new push socket: %s", err.Error())
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Dial(url); err != nil {
		die("can't dial on push socket: %s", err.Error())
	}
	fmt.Printf("NODE1: SENDING \"%s\"\n", msg)
	if err = sock.Send([]byte(msg)); err != nil {
		die("can't send message on push socket: %s", err.Error())
	}
	sock.Close()
}
示例#23
0
func node0(url string) {
	var sock mangos.Socket
	var err error
	var msg []byte
	if sock, err = pull.NewSocket(); err != nil {
		die("can't get new pull socket: %s", err)
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Listen(url); err != nil {
		die("can't listen on pull socket: %s", err.Error())
	}
	for {
		// Could also use sock.RecvMsg to get header
		msg, err = sock.Recv()
		fmt.Printf("NODE0: RECEIVED \"%s\"\n", msg)
	}
}
示例#24
0
func newCmdServer(addr string) (mangos.Socket, error) {
	log.Info("sensor: creating cmd server...")
	socket, err := rep.NewSocket()
	if err != nil {
		return nil, err
	}

	if err := socket.SetOption(mangos.OptionRecvDeadline, time.Second*3); err != nil {
		socket.Close()
		return nil, err
	}

	//socket.AddTransport(ipc.NewTransport())
	socket.AddTransport(tcp.NewTransport())
	if err := socket.Listen(addr); err != nil {
		socket.Close()
		return nil, err
	}

	return socket, nil
}
示例#25
0
func newEvtPublisher(addr string) (mangos.Socket, error) {
	log.Info("sensor: creating event publisher...")
	socket, err := pub.NewSocket()
	if err != nil {
		return nil, err
	}

	if err := socket.SetOption(mangos.OptionSendDeadline, time.Second*3); err != nil {
		socket.Close()
		return nil, err
	}

	//socket.AddTransport(ipc.NewTransport())
	socket.AddTransport(tcp.NewTransport())
	if err = socket.Listen(addr); err != nil {
		socket.Close()
		return nil, err
	}

	return socket, nil
}
示例#26
0
func server(url string) {
	var sock mangos.Socket
	var err error
	if sock, err = pub.NewSocket(); err != nil {
		die("can't get new pub socket: %s", err)
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Listen(url); err != nil {
		die("can't listen on pub socket: %s", err.Error())
	}
	for {
		// Could also use sock.RecvMsg to get header
		d := date()
		fmt.Printf("SERVER: PUBLISHING DATE %s\n", d)
		if err = sock.Send([]byte(d)); err != nil {
			die("Failed publishing: %s", err.Error())
		}
		time.Sleep(time.Second)
	}
}
示例#27
0
文件: bus.go 项目: laszlo-kiss/mangos
func node(args []string) {
	var sock mangos.Socket
	var err error
	var msg []byte
	var x int

	if sock, err = bus.NewSocket(); err != nil {
		die("bus.NewSocket: %s", err)
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Listen(args[2]); err != nil {
		die("sock.Listen: %s", err.Error())
	}

	// wait for everyone to start listening
	time.Sleep(time.Second)
	for x = 3; x < len(args); x++ {
		if err = sock.Dial(args[x]); err != nil {
			die("socket.Dial: %s", err.Error())
		}
	}

	// wait for everyone to join
	time.Sleep(time.Second)

	fmt.Printf("%s: SENDING '%s' ONTO BUS\n", args[1], args[1])
	if err = sock.Send([]byte(args[1])); err != nil {
		die("sock.Send: %s", err.Error())
	}
	for {
		if msg, err = sock.Recv(); err != nil {
			die("sock.Recv: %s", err.Error())
		}
		fmt.Printf("%s: RECEIVED \"%s\" FROM BUS\n", args[1],
			string(msg))

	}
}
示例#28
0
func clientWorker(url string, id int) {
	var sock mangos.Socket
	var m *mangos.Message
	var err error

	if sock, err = req.NewSocket(); err != nil {
		die("can't get new req socket: %s", err.Error())
	}

	// Leave this in Cooked mode!

	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Dial(url); err != nil {
		die("can't dial on req socket: %s", err.Error())
	}

	// send an empty messsage
	m = mangos.NewMessage(1)
	if err = sock.SendMsg(m); err != nil {
		die("can't send request: %s", err.Error())
	}

	if m, err = sock.RecvMsg(); err != nil {
		die("can't recv reply: %s", err.Error())
	}
	sock.Close()

	if len(m.Body) != 4 {
		die("bad response len: %d", len(m.Body))
	}

	worker := binary.BigEndian.Uint32(m.Body[0:])

	L.Lock()
	fmt.Printf("Client: %4d   Server: %4d\n", id, worker)
	L.Unlock()
}
示例#29
0
func node1(url string) {
	var sock mangos.Socket
	var err error
	var msg []byte

	if sock, err = req.NewSocket(); err != nil {
		die("can't get new req socket: %s", err.Error())
	}
	sock.AddTransport(ipc.NewTransport())
	sock.AddTransport(tcp.NewTransport())
	if err = sock.Dial(url); err != nil {
		die("can't dial on req socket: %s", err.Error())
	}
	fmt.Printf("NODE1: SENDING DATE REQUEST %s\n", "DATE")
	if err = sock.Send([]byte("DATE")); err != nil {
		die("can't send message on push socket: %s", err.Error())
	}
	if msg, err = sock.Recv(); err != nil {
		die("can't receive date: %s", err.Error())
	}
	fmt.Printf("NODE1: RECEIVED DATE %s\n", string(msg))
	sock.Close()
}
示例#30
0
文件: client.go 项目: sb10/vrpipe
// Connect creates a connection to the jobqueue server, specific to a single
// queue. Timeout determines how long to wait for a response from the server,
// not only while connecting, but for all subsequent interactions with it using
// the returned Client.
func Connect(addr string, queue string, timeout time.Duration) (c *Client, err error) {
	sock, err := req.NewSocket()
	if err != nil {
		return
	}

	err = sock.SetOption(mangos.OptionRecvDeadline, timeout)
	if err != nil {
		return
	}

	sock.AddTransport(tcp.NewTransport())

	err = sock.Dial("tcp://" + addr)
	if err != nil {
		return
	}

	// clients identify themselves (only for the purpose of calling methods that
	// require the client has previously used Require()) with a UUID; v4 is used
	// since speed doesn't matter: a typical client executable will only
	// Connect() once; on the other hand, we avoid any possible problem with
	// running on machines with low time resolution
	c = &Client{sock: sock, queue: queue, ch: new(codec.BincHandle), clientid: uuid.NewV4()}

	// Dial succeeds even when there's no server up, so we test the connection
	// works with a Ping()
	ok := c.Ping(timeout)
	if !ok {
		sock.Close()
		c = nil
		err = Error{queue, "Connect", "", ErrNoServer}
	}

	return
}