Isolate race condition further

wsnet/conn.go

@@ -56,20 +56,25 @@ type conn struct {
 	rw   datachannel.ReadWriteCloser
 
 	sendMore    chan struct{}
-	closedMutex sync.Mutex
+	closedMutex sync.RWMutex
 	closed      bool
+
+	writeMutex sync.Mutex
 }
 
 func (c *conn) init() {
-	c.sendMore = make(chan struct{})
+	c.sendMore = make(chan struct{}, 1)
 	c.dc.SetBufferedAmountLowThreshold(bufferedAmountLowThreshold)
 	c.dc.OnBufferedAmountLow(func() {
-		c.closedMutex.Lock()
-		defer c.closedMutex.Unlock()
+		c.closedMutex.RLock()
+		defer c.closedMutex.RUnlock()
 		if c.closed {
 			return
 		}
-		c.sendMore <- struct{}{}
+		select {
+		case c.sendMore <- struct{}{}:
+		default:
+		}
 	})
 }
 
@@ -78,12 +83,16 @@ func (c *conn) Read(b []byte) (n int, err error) {
 }
 
 func (c *conn) Write(b []byte) (n int, err error) {
+	c.writeMutex.Lock()
+	defer c.writeMutex.Unlock()
 	if len(b) > maxMessageLength {
 		return 0, fmt.Errorf("outbound packet larger than maximum message size: %d", maxMessageLength)
 	}
 	if c.dc.BufferedAmount()+uint64(len(b)) >= maxBufferedAmount {
 		<-c.sendMore
 	}
+	// Uncomment this line for it to work.
+	// time.Sleep(time.Microsecond)
 	return c.rw.Write(b)
 }
 

wsnet/dial_test.go

@@ -167,11 +167,12 @@ func BenchmarkThroughput(b *testing.B) {
 	sizes := []int64{
 		// 4,
 		// 16,
+		128,
 		// 256,
 		// 1024,
 		// 4096,
 		// 16384,
-		32768,
+		// 32768,
 	}
 
 	listener, err := net.Listen("tcp", "0.0.0.0:0")

wsnet/rtc.go

@@ -161,7 +161,7 @@ func newPeerConnection(servers []webrtc.ICEServer) (*webrtc.PeerConnection, erro
 	se.DetachDataChannels()
 	se.SetICETimeouts(time.Second*5, time.Second*5, time.Second*2)
 	lf := logging.NewDefaultLoggerFactory()
-	lf.DefaultLogLevel = logging.LogLevelDebug
+	lf.DefaultLogLevel = logging.LogLevelDisabled
 	se.LoggerFactory = lf
 
 	// If one server is provided and we know it's TURN, we can set the