This PR fixes various tunnel race conditions

tunnel/default.go

@@ -854,16 +854,6 @@ func (t *tun) connect() error {
 		}
 	}()
 
-	// setup links
-	t.setupLinks()
-
-	// process outbound messages to be sent
-	// process sends to all links
-	go t.process()
-
-	// monitor links
-	go t.monitor()
-
 	return nil
 }
 
@@ -889,6 +879,16 @@ func (t *tun) Connect() error {
 	// create new close channel
 	t.closed = make(chan bool)
 
+	// setup links
+	t.setupLinks()
+
+	// process outbound messages to be sent
+	// process sends to all links
+	go t.process()
+
+	// monitor links
+	go t.monitor()
+
 	return nil
 }
 

tunnel/link.go

@@ -229,7 +229,10 @@ func (l *link) manage() {
 			// check the type of message
 			switch {
 			case bytes.Equal(p.message.Body, linkRequest):
+				l.RLock()
 				log.Tracef("Link %s received link request %v", l.id, p.message.Body)
+				l.RUnlock()
+
 				// send response
 				if err := send(linkResponse); err != nil {
 					l.Lock()
@@ -239,7 +242,10 @@ func (l *link) manage() {
 			case bytes.Equal(p.message.Body, linkResponse):
 				// set round trip time
 				d := time.Since(now)
+				l.RLock()
 				log.Tracef("Link %s received link response in %v", p.message.Body, d)
+				l.RUnlock()
+				// set the RTT
 				l.setRTT(d)
 			}
 		case <-t.C:

tunnel/tunnel.go

@@ -36,26 +36,27 @@ type Mode uint8
 // and Micro-Tunnel-Session header. The tunnel id is a hash of
 // the address being requested.
 type Tunnel interface {
+	// Init initializes tunnel with options
 	Init(opts ...Option) error
-	// Address the tunnel is listening on
+	// Address returns the address the tunnel is listening on
 	Address() string
 	// Connect connects the tunnel
 	Connect() error
 	// Close closes the tunnel
 	Close() error
-	// All the links the tunnel is connected to
+	// Links returns all the links the tunnel is connected to
 	Links() []Link
-	// Connect to a channel
+	// Dial allows a client to connect to a channel
 	Dial(channel string, opts ...DialOption) (Session, error)
-	// Accept connections on a channel
+	// Listen allows to accept connections on a channel
 	Listen(channel string, opts ...ListenOption) (Listener, error)
-	// Name of the tunnel implementation
+	// String returns the name of the tunnel implementation
 	String() string
 }
 
 // Link represents internal links to the tunnel
 type Link interface {
-	// The id of the link
+	// Id returns the link unique Id
 	Id() string
 	// Delay is the current load on the link (lower is better)
 	Delay() int64

tunnel/tunnel_reconnect_test.go

@@ -0,0 +1,55 @@
+// +build !race
+
+package tunnel
+
+import (
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestReconnectTunnel(t *testing.T) {
+	// create a new tunnel client
+	tunA := NewTunnel(
+		Address("127.0.0.1:9096"),
+		Nodes("127.0.0.1:9097"),
+	)
+
+	// create a new tunnel server
+	tunB := NewTunnel(
+		Address("127.0.0.1:9097"),
+	)
+
+	// start tunnel
+	err := tunB.Connect()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer tunB.Close()
+
+	// we manually override the tunnel.ReconnectTime value here
+	// this is so that we make the reconnects faster than the default 5s
+	ReconnectTime = 200 * time.Millisecond
+
+	// start tunnel
+	err = tunA.Connect()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer tunA.Close()
+
+	wait := make(chan bool)
+
+	var wg sync.WaitGroup
+
+	wg.Add(1)
+	// start tunnel listener
+	go testBrokenTunAccept(t, tunB, wait, &wg)
+
+	wg.Add(1)
+	// start tunnel sender
+	go testBrokenTunSend(t, tunA, wait, &wg)
+
+	// wait until done
+	wg.Wait()
+}

tunnel/tunnel_test.go

@@ -247,52 +247,6 @@ func testBrokenTunSend(t *testing.T, tun Tunnel, wait chan bool, wg *sync.WaitGr
 	<-wait
 }
 
-func TestReconnectTunnel(t *testing.T) {
-	// create a new tunnel client
-	tunA := NewTunnel(
-		Address("127.0.0.1:9096"),
-		Nodes("127.0.0.1:9097"),
-	)
-
-	// create a new tunnel server
-	tunB := NewTunnel(
-		Address("127.0.0.1:9097"),
-	)
-
-	// start tunnel
-	err := tunB.Connect()
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer tunB.Close()
-
-	// we manually override the tunnel.ReconnectTime value here
-	// this is so that we make the reconnects faster than the default 5s
-	ReconnectTime = 200 * time.Millisecond
-
-	// start tunnel
-	err = tunA.Connect()
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer tunA.Close()
-
-	wait := make(chan bool)
-
-	var wg sync.WaitGroup
-
-	wg.Add(1)
-	// start tunnel listener
-	go testBrokenTunAccept(t, tunB, wait, &wg)
-
-	wg.Add(1)
-	// start tunnel sender
-	go testBrokenTunSend(t, tunA, wait, &wg)
-
-	// wait until done
-	wg.Wait()
-}
-
 func TestTunnelRTTRate(t *testing.T) {
 	// create a new tunnel client
 	tunA := NewTunnel(