receiving worker

transport/internet/kcp/connection.go

@@ -85,7 +85,7 @@ func (this *Connection) Read(b []byte) (int, error) {
 	if this == nil || this.kcp.state == StateTerminating || this.kcp.state == StateTerminated {
 		return 0, io.EOF
 	}
-	return this.kcp.rcv_queue.Read(b)
+	return this.kcp.receivingWorker.Read(b)
 }
 
 // Write implements the Conn Write method.
@@ -177,7 +177,7 @@ func (this *Connection) SetReadDeadline(t time.Time) error {
 	}
 	this.kcpAccess.Lock()
 	defer this.kcpAccess.Unlock()
-	this.kcp.rcv_queue.SetReadDeadline(t)
+	this.kcp.receivingWorker.SetReadDeadline(t)
 	return nil
 }
 

transport/internet/kcp/kcp.go

@@ -32,25 +32,21 @@ type KCP struct {
 	lastIncomingTime uint32
 	lastPayloadTime  uint32
 	sendingUpdated   bool
-	receivingUpdated bool
 	lastPingTime     uint32
 
-	mss                             uint32
-	snd_una, snd_nxt, rcv_nxt       uint32
-	rx_rttvar, rx_srtt, rx_rto      uint32
-	snd_wnd, rcv_wnd, rmt_wnd, cwnd uint32
-	current, interval               uint32
+	mss                        uint32
+	snd_una, snd_nxt           uint32
+	rx_rttvar, rx_srtt, rx_rto uint32
+	snd_wnd, rmt_wnd, cwnd     uint32
+	current, interval          uint32
 
-	snd_queue *SendingQueue
-	rcv_queue *ReceivingQueue
-	snd_buf   *SendingWindow
-	rcv_buf   *ReceivingWindow
-
-	acklist *AckList
+	snd_queue       *SendingQueue
+	snd_buf         *SendingWindow
+	receivingWorker *ReceivingWorker
 
 	fastresend        int32
 	congestionControl bool
-	output            *SegmentWriter
+	output            *BufferedSegmentWriter
 }
 
 // NewKCP create a new kcp control object, 'conv' must equal in two endpoint
@@ -60,18 +56,15 @@ func NewKCP(conv uint16, output *AuthenticationWriter) *KCP {
 	kcp := new(KCP)
 	kcp.conv = conv
 	kcp.snd_wnd = effectiveConfig.GetSendingWindowSize()
-	kcp.rcv_wnd = effectiveConfig.GetReceivingWindowSize()
 	kcp.rmt_wnd = 32
 	kcp.mss = output.Mtu() - DataSegmentOverhead
 	kcp.rx_rto = 100
 	kcp.interval = effectiveConfig.Tti
 	kcp.output = NewSegmentWriter(output)
-	kcp.rcv_buf = NewReceivingWindow(effectiveConfig.GetReceivingWindowSize())
 	kcp.snd_queue = NewSendingQueue(effectiveConfig.GetSendingQueueSize())
-	kcp.rcv_queue = NewReceivingQueue()
-	kcp.acklist = NewACKList(kcp)
 	kcp.snd_buf = NewSendingWindow(kcp, effectiveConfig.GetSendingWindowSize())
 	kcp.cwnd = kcp.snd_wnd
+	kcp.receivingWorker = NewReceivingWorker(kcp)
 	return kcp
 }
 
@@ -81,13 +74,13 @@ func (kcp *KCP) SetState(state State) {
 
 	switch state {
 	case StateReadyToClose:
-		kcp.rcv_queue.Close()
+		kcp.receivingWorker.CloseRead()
 	case StatePeerClosed:
 		kcp.ClearSendQueue()
 	case StateTerminating:
-		kcp.rcv_queue.Close()
+		kcp.receivingWorker.CloseRead()
 	case StateTerminated:
-		kcp.rcv_queue.Close()
+		kcp.receivingWorker.CloseRead()
 	}
 }
 
@@ -115,23 +108,6 @@ func (kcp *KCP) OnClose() {
 	}
 }
 
-// DumpReceivingBuf moves available data from rcv_buf -> rcv_queue
-// @Private
-func (kcp *KCP) DumpReceivingBuf() {
-	for {
-		seg := kcp.rcv_buf.RemoveFirst()
-		if seg == nil {
-			break
-		}
-		kcp.rcv_queue.Put(seg.Data)
-		seg.Data = nil
-
-		kcp.rcv_buf.Advance()
-		kcp.rcv_nxt++
-		kcp.receivingUpdated = true
-	}
-}
-
 // Send is user/upper level send, returns below zero for error
 func (kcp *KCP) Send(buffer []byte) int {
 	nBytes := 0
@@ -214,25 +190,6 @@ func (kcp *KCP) HandleReceivingNext(receivingNext uint32) {
 	kcp.snd_buf.Clear(receivingNext)
 }
 
-func (kcp *KCP) HandleSendingNext(sendingNext uint32) {
-	kcp.acklist.Clear(sendingNext)
-}
-
-func (kcp *KCP) parse_data(newseg *DataSegment) {
-	sn := newseg.Number
-	if _itimediff(sn, kcp.rcv_nxt+kcp.rcv_wnd) >= 0 ||
-		_itimediff(sn, kcp.rcv_nxt) < 0 {
-		return
-	}
-
-	idx := sn - kcp.rcv_nxt
-	if !kcp.rcv_buf.Set(idx, newseg) {
-		newseg.Release()
-	}
-
-	kcp.DumpReceivingBuf()
-}
-
 // Input when you received a low level packet (eg. UDP packet), call it
 func (kcp *KCP) Input(data []byte) int {
 	kcp.lastIncomingTime = kcp.current
@@ -249,10 +206,7 @@ func (kcp *KCP) Input(data []byte) int {
 		switch seg := seg.(type) {
 		case *DataSegment:
 			kcp.HandleOption(seg.Opt)
-			kcp.HandleSendingNext(seg.SendingNext)
-			kcp.acklist.Add(seg.Number, seg.Timestamp)
-			kcp.receivingUpdated = true
-			kcp.parse_data(seg)
+			kcp.receivingWorker.ProcessSegment(seg)
 			kcp.lastPayloadTime = kcp.current
 		case *ACKSegment:
 			kcp.HandleOption(seg.Opt)
@@ -288,7 +242,7 @@ func (kcp *KCP) Input(data []byte) int {
 				}
 			}
 			kcp.HandleReceivingNext(seg.ReceivinNext)
-			kcp.HandleSendingNext(seg.SendingNext)
+			kcp.receivingWorker.ProcessSendingNext(seg.SendingNext)
 			kcp.shrink_buf()
 		default:
 		}
@@ -330,9 +284,7 @@ func (kcp *KCP) flush() {
 	current := kcp.current
 
 	// flush acknowledges
-	if kcp.acklist.Flush() {
-		kcp.receivingUpdated = false
-	}
+	kcp.receivingWorker.Flush()
 
 	// calculate window size
 	cwnd := kcp.snd_una + kcp.snd_wnd
@@ -359,11 +311,11 @@ func (kcp *KCP) flush() {
 		kcp.sendingUpdated = false
 	}
 
-	if kcp.sendingUpdated || kcp.receivingUpdated || _itimediff(kcp.current, kcp.lastPingTime) >= 5000 {
+	if kcp.sendingUpdated || kcp.receivingWorker.PingNecessary() || _itimediff(kcp.current, kcp.lastPingTime) >= 5000 {
 		seg := &CmdOnlySegment{
 			Conv:         kcp.conv,
 			Cmd:          SegmentCommandPing,
-			ReceivinNext: kcp.rcv_nxt,
+			ReceivinNext: kcp.receivingWorker.nextNumber,
 			SendingNext:  kcp.snd_una,
 		}
 		if kcp.state == StateReadyToClose {
@@ -372,7 +324,6 @@ func (kcp *KCP) flush() {
 		kcp.output.Write(seg)
 		kcp.lastPingTime = kcp.current
 		kcp.sendingUpdated = false
-		kcp.receivingUpdated = false
 	}
 
 	// flash remain segments

transport/internet/kcp/output.go

@@ -8,21 +8,25 @@ import (
 	v2io "github.com/v2ray/v2ray-core/common/io"
 )
 
-type SegmentWriter struct {
+type SegmentWriter interface {
+	Write(seg ISegment)
+}
+
+type BufferedSegmentWriter struct {
 	sync.Mutex
 	mtu    uint32
 	buffer *alloc.Buffer
 	writer v2io.Writer
 }
 
-func NewSegmentWriter(writer *AuthenticationWriter) *SegmentWriter {
-	return &SegmentWriter{
+func NewSegmentWriter(writer *AuthenticationWriter) *BufferedSegmentWriter {
+	return &BufferedSegmentWriter{
 		mtu:    writer.Mtu(),
 		writer: writer,
 	}
 }
 
-func (this *SegmentWriter) Write(seg ISegment) {
+func (this *BufferedSegmentWriter) Write(seg ISegment) {
 	this.Lock()
 	defer this.Unlock()
 
@@ -38,12 +42,12 @@ func (this *SegmentWriter) Write(seg ISegment) {
 	this.buffer.Append(seg.Bytes(nil))
 }
 
-func (this *SegmentWriter) FlushWithoutLock() {
+func (this *BufferedSegmentWriter) FlushWithoutLock() {
 	this.writer.Write(this.buffer)
 	this.buffer = nil
 }
 
-func (this *SegmentWriter) Flush() {
+func (this *BufferedSegmentWriter) Flush() {
 	this.Lock()
 	defer this.Unlock()
 

transport/internet/kcp/receiving.go

@@ -58,7 +58,6 @@ func (this *ReceivingWindow) Advance() {
 }
 
 type ReceivingQueue struct {
-	sync.RWMutex
 	closed  bool
 	cache   *alloc.Buffer
 	queue   chan *alloc.Buffer
@@ -104,12 +103,9 @@ L:
 			if totalBytes > 0 {
 				break L
 			}
-			this.RLock()
 			if !this.timeout.IsZero() && this.timeout.Before(time.Now()) {
-				this.RUnlock()
 				return totalBytes, errTimeout
 			}
-			this.RUnlock()
 			timeToSleep += 500 * time.Millisecond
 		}
 	}
@@ -117,30 +113,26 @@ L:
 	return totalBytes, nil
 }
 
-func (this *ReceivingQueue) Put(payload *alloc.Buffer) {
-	this.RLock()
-	defer this.RUnlock()
-
+func (this *ReceivingQueue) Put(payload *alloc.Buffer) bool {
 	if this.closed {
 		payload.Release()
-		return
+		return false
 	}
 
-	this.queue <- payload
+	select {
+	case this.queue <- payload:
+		return true
+	default:
+		return false
+	}
 }
 
 func (this *ReceivingQueue) SetReadDeadline(t time.Time) error {
-	this.Lock()
-	defer this.Unlock()
-
 	this.timeout = t
 	return nil
 }
 
 func (this *ReceivingQueue) Close() {
-	this.Lock()
-	defer this.Unlock()
-
 	if this.closed {
 		return
 	}
@@ -149,15 +141,15 @@ func (this *ReceivingQueue) Close() {
 }
 
 type AckList struct {
-	kcp        *KCP
+	writer     SegmentWriter
 	timestamps []uint32
 	numbers    []uint32
 	nextFlush  []uint32
 }
 
-func NewACKList(kcp *KCP) *AckList {
+func NewACKList(writer SegmentWriter) *AckList {
 	return &AckList{
-		kcp:        kcp,
+		writer:     writer,
 		timestamps: make([]uint32, 0, 32),
 		numbers:    make([]uint32, 0, 32),
 		nextFlush:  make([]uint32, 0, 32),
@@ -189,16 +181,8 @@ func (this *AckList) Clear(una uint32) {
 	}
 }
 
-func (this *AckList) Flush() bool {
-	seg := &ACKSegment{
-		Conv:            this.kcp.conv,
-		ReceivingNext:   this.kcp.rcv_nxt,
-		ReceivingWindow: this.kcp.rcv_nxt + this.kcp.rcv_wnd,
-	}
-	if this.kcp.state == StateReadyToClose {
-		seg.Opt = SegmentOptionClose
-	}
-	current := this.kcp.current
+func (this *AckList) Flush(current uint32) {
+	seg := new(ACKSegment)
 	for i := 0; i < len(this.numbers); i++ {
 		if this.nextFlush[i] <= current {
 			seg.Count++
@@ -211,8 +195,124 @@ func (this *AckList) Flush() bool {
 		}
 	}
 	if seg.Count > 0 {
-		this.kcp.output.Write(seg)
-		return true
+		this.writer.Write(seg)
 	}
-	return false
+}
+
+type ReceivingWorker struct {
+	sync.Mutex
+	kcp        *KCP
+	queue      *ReceivingQueue
+	window     *ReceivingWindow
+	acklist    *AckList
+	updated    bool
+	nextNumber uint32
+	windowSize uint32
+}
+
+func NewReceivingWorker(kcp *KCP) *ReceivingWorker {
+	windowSize := effectiveConfig.GetReceivingWindowSize()
+	worker := &ReceivingWorker{
+		kcp:        kcp,
+		queue:      NewReceivingQueue(),
+		window:     NewReceivingWindow(windowSize),
+		windowSize: windowSize,
+	}
+	worker.acklist = NewACKList(worker)
+	return worker
+}
+
+func (this *ReceivingWorker) ProcessSendingNext(number uint32) {
+	this.Lock()
+	defer this.Unlock()
+
+	this.acklist.Clear(number)
+}
+
+func (this *ReceivingWorker) ProcessSegment(seg *DataSegment) {
+	number := seg.Number
+	if _itimediff(number, this.nextNumber+this.windowSize) >= 0 || _itimediff(number, this.nextNumber) < 0 {
+		return
+	}
+
+	this.ProcessSendingNext(seg.SendingNext)
+
+	this.Lock()
+	this.acklist.Add(number, seg.Timestamp)
+
+	idx := number - this.nextNumber
+
+	if !this.window.Set(idx, seg) {
+		seg.Release()
+	}
+	this.Unlock()
+
+	this.DumpWindow()
+}
+
+// @Private
+func (this *ReceivingWorker) DumpWindow() {
+	this.Lock()
+	defer this.Unlock()
+
+	for {
+		seg := this.window.RemoveFirst()
+		if seg == nil {
+			break
+		}
+
+		if !this.queue.Put(seg.Data) {
+			this.window.Set(0, seg)
+			break
+		}
+
+		seg.Data = nil
+		this.window.Advance()
+		this.nextNumber++
+		this.updated = true
+	}
+}
+
+func (this *ReceivingWorker) Read(b []byte) (int, error) {
+	this.Lock()
+	defer this.Unlock()
+
+	return this.queue.Read(b)
+}
+
+func (this *ReceivingWorker) SetReadDeadline(t time.Time) {
+	this.Lock()
+	defer this.Unlock()
+
+	this.queue.SetReadDeadline(t)
+}
+
+func (this *ReceivingWorker) Flush() {
+	this.Lock()
+	defer this.Unlock()
+
+	this.acklist.Flush(this.kcp.current)
+}
+
+func (this *ReceivingWorker) Write(seg ISegment) {
+	ackSeg := seg.(*ACKSegment)
+	ackSeg.Conv = this.kcp.conv
+	ackSeg.ReceivingNext = this.nextNumber
+	ackSeg.ReceivingWindow = this.nextNumber + this.windowSize
+	if this.kcp.state == StateReadyToClose {
+		ackSeg.Opt = SegmentOptionClose
+	}
+	this.kcp.output.Write(ackSeg)
+	this.updated = false
+}
+
+func (this *ReceivingWorker) CloseRead() {
+	this.Lock()
+	defer this.Unlock()
+
+	this.queue.Close()
+}
+
+func (this *ReceivingWorker) PingNecessary() bool {
+	return this.updated
 }