don't report blocked streams as active for sending data

internal/flowcontrol/base_flow_controller.go

@@ -13,7 +13,6 @@ type baseFlowController struct {
 	// for sending data
 	bytesSent  protocol.ByteCount
 	sendWindow protocol.ByteCount
-	lastBlockedAt protocol.ByteCount
 
 	// for receiving data
 	mutex                sync.RWMutex
@@ -78,17 +77,6 @@ func (c *baseFlowController) getWindowUpdate() protocol.ByteCount {
 	return c.receiveWindow
 }
 
-// IsBlocked says if it is newly blocked by flow control.
-// For every offset, it only returns true once.
-// If it is blocked, the offset is returned.
-func (c *baseFlowController) IsNewlyBlocked() (bool, protocol.ByteCount) {
-	if c.sendWindowSize() != 0 || c.sendWindow == c.lastBlockedAt {
-		return false, 0
-	}
-	c.lastBlockedAt = c.sendWindow
-	return true, c.sendWindow
-}
-
 // maybeAdjustWindowSize increases the receiveWindowSize if we're sending updates too often.
 // For details about auto-tuning, see https://docs.google.com/document/d/1SExkMmGiz8VYzV3s9E35JQlJ73vhzCekKkDi85F1qCE/edit?usp=sharing.
 func (c *baseFlowController) maybeAdjustWindowSize() {

internal/flowcontrol/base_flow_controller_test.go

@@ -49,29 +49,6 @@ var _ = Describe("Base Flow controller", func() {
 			controller.UpdateSendWindow(10)
 			Expect(controller.sendWindowSize()).To(Equal(protocol.ByteCount(20)))
 		})
-
-		It("says when it's blocked", func() {
-			controller.UpdateSendWindow(100)
-			Expect(controller.IsNewlyBlocked()).To(BeFalse())
-			controller.AddBytesSent(100)
-			blocked, offset := controller.IsNewlyBlocked()
-			Expect(blocked).To(BeTrue())
-			Expect(offset).To(Equal(protocol.ByteCount(100)))
-		})
-
-		It("doesn't say that it's newly blocked multiple times for the same offset", func() {
-			controller.UpdateSendWindow(100)
-			controller.AddBytesSent(100)
-			newlyBlocked, offset := controller.IsNewlyBlocked()
-			Expect(newlyBlocked).To(BeTrue())
-			Expect(offset).To(Equal(protocol.ByteCount(100)))
-			newlyBlocked, _ = controller.IsNewlyBlocked()
-			Expect(newlyBlocked).To(BeFalse())
-			controller.UpdateSendWindow(150)
-			controller.AddBytesSent(150)
-			newlyBlocked, offset = controller.IsNewlyBlocked()
-			Expect(newlyBlocked).To(BeTrue())
-		})
 	})
 
 	Context("receive flow control", func() {

internal/flowcontrol/connection_flow_controller.go

@@ -10,6 +10,7 @@ import (
 )
 
 type connectionFlowController struct {
+	lastBlockedAt protocol.ByteCount
 	baseFlowController
 }
 
@@ -36,6 +37,17 @@ func (c *connectionFlowController) SendWindowSize() protocol.ByteCount {
 	return c.baseFlowController.sendWindowSize()
 }
 
+// IsNewlyBlocked says if it is newly blocked by flow control.
+// For every offset, it only returns true once.
+// If it is blocked, the offset is returned.
+func (c *connectionFlowController) IsNewlyBlocked() (bool, protocol.ByteCount) {
+	if c.sendWindowSize() != 0 || c.sendWindow == c.lastBlockedAt {
+		return false, 0
+	}
+	c.lastBlockedAt = c.sendWindow
+	return true, c.sendWindow
+}
+
 // IncrementHighestReceived adds an increment to the highestReceived value
 func (c *connectionFlowController) IncrementHighestReceived(increment protocol.ByteCount) error {
 	c.mutex.Lock()

internal/flowcontrol/connection_flow_controller_test.go

@@ -77,6 +77,31 @@ var _ = Describe("Connection Flow controller", func() {
 		})
 	})
 
+	Context("send flow control", func() {
+		It("says when it's blocked", func() {
+			controller.UpdateSendWindow(100)
+			Expect(controller.IsNewlyBlocked()).To(BeFalse())
+			controller.AddBytesSent(100)
+			blocked, offset := controller.IsNewlyBlocked()
+			Expect(blocked).To(BeTrue())
+			Expect(offset).To(Equal(protocol.ByteCount(100)))
+		})
+
+		It("doesn't say that it's newly blocked multiple times for the same offset", func() {
+			controller.UpdateSendWindow(100)
+			controller.AddBytesSent(100)
+			newlyBlocked, offset := controller.IsNewlyBlocked()
+			Expect(newlyBlocked).To(BeTrue())
+			Expect(offset).To(Equal(protocol.ByteCount(100)))
+			newlyBlocked, _ = controller.IsNewlyBlocked()
+			Expect(newlyBlocked).To(BeFalse())
+			controller.UpdateSendWindow(150)
+			controller.AddBytesSent(150)
+			newlyBlocked, offset = controller.IsNewlyBlocked()
+			Expect(newlyBlocked).To(BeTrue())
+		})
+	})
+
 	Context("setting the minimum window size", func() {
 		var (
 			oldWindowSize     protocol.ByteCount

internal/flowcontrol/interface.go

@@ -5,7 +5,6 @@ import "github.com/lucas-clemente/quic-go/internal/protocol"
 type flowController interface {
 	// for sending
 	SendWindowSize() protocol.ByteCount
-	IsNewlyBlocked() (bool, protocol.ByteCount)
 	UpdateSendWindow(protocol.ByteCount)
 	AddBytesSent(protocol.ByteCount)
 	// for receiving
@@ -16,6 +15,8 @@ type flowController interface {
 // A StreamFlowController is a flow controller for a QUIC stream.
 type StreamFlowController interface {
 	flowController
+	// for sending
+	IsBlocked() (bool, protocol.ByteCount)
 	// for receiving
 	// UpdateHighestReceived should be called when a new highest offset is received
 	// final has to be to true if this is the final offset of the stream, as contained in a STREAM frame with FIN bit, and the RST_STREAM frame
@@ -27,6 +28,8 @@ type StreamFlowController interface {
 // The ConnectionFlowController is the flow controller for the connection.
 type ConnectionFlowController interface {
 	flowController
+	// for sending
+	IsNewlyBlocked() (bool, protocol.ByteCount)
 }
 
 type connectionFlowControllerI interface {

internal/flowcontrol/stream_flow_controller.go

@@ -109,6 +109,15 @@ func (c *streamFlowController) SendWindowSize() protocol.ByteCount {
 	return window
 }
 
+// IsBlocked says if it is blocked by stream-level flow control.
+// If it is blocked, the offset is returned.
+func (c *streamFlowController) IsBlocked() (bool, protocol.ByteCount) {
+	if c.sendWindowSize() != 0 {
+		return false, 0
+	}
+	return true, c.sendWindow
+}
+
 func (c *streamFlowController) HasWindowUpdate() bool {
 	c.mutex.Lock()
 	hasWindowUpdate := !c.receivedFinalOffset && c.hasWindowUpdate()

internal/flowcontrol/stream_flow_controller_test.go

@@ -247,7 +247,7 @@ var _ = Describe("Stream Flow controller", func() {
 			controller.AddBytesSent(50)
 			blocked, _ := controller.connection.IsNewlyBlocked()
 			Expect(blocked).To(BeTrue())
-			Expect(controller.IsNewlyBlocked()).To(BeFalse())
+			Expect(controller.IsBlocked()).To(BeFalse())
 		})
 	})
 })

internal/mocks/stream_flow_controller.go

@@ -78,17 +78,17 @@ func (mr *MockStreamFlowControllerMockRecorder) HasWindowUpdate() *gomock.Call {
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "HasWindowUpdate", reflect.TypeOf((*MockStreamFlowController)(nil).HasWindowUpdate))
 }
 
-// IsNewlyBlocked mocks base method
-func (m *MockStreamFlowController) IsNewlyBlocked() (bool, protocol.ByteCount) {
-	ret := m.ctrl.Call(m, "IsNewlyBlocked")
+// IsBlocked mocks base method
+func (m *MockStreamFlowController) IsBlocked() (bool, protocol.ByteCount) {
+	ret := m.ctrl.Call(m, "IsBlocked")
 	ret0, _ := ret[0].(bool)
 	ret1, _ := ret[1].(protocol.ByteCount)
 	return ret0, ret1
 }
 
-// IsNewlyBlocked indicates an expected call of IsNewlyBlocked
-func (mr *MockStreamFlowControllerMockRecorder) IsNewlyBlocked() *gomock.Call {
-	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "IsNewlyBlocked", reflect.TypeOf((*MockStreamFlowController)(nil).IsNewlyBlocked))
+// IsBlocked indicates an expected call of IsBlocked
+func (mr *MockStreamFlowControllerMockRecorder) IsBlocked() *gomock.Call {
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "IsBlocked", reflect.TypeOf((*MockStreamFlowController)(nil).IsBlocked))
 }
 
 // SendWindowSize mocks base method

send_stream.go

@@ -36,6 +36,7 @@ type sendStream struct {
 	writeDeadline  time.Time
 
 	flowController flowcontrol.StreamFlowController
+
 	version protocol.VersionNumber
 }
 
@@ -141,16 +142,25 @@ func (s *sendStream) popStreamFrame(maxBytes protocol.ByteCount) (*wire.StreamFr
 	}
 	frame.Data, frame.FinBit = s.getDataForWriting(maxBytes - frameLen)
 	if len(frame.Data) == 0 && !frame.FinBit {
-		return nil, s.dataForWriting != nil
+		// this can happen if:
+		// - popStreamFrame is called but there's no data for writing
+		// - there's data for writing, but the stream is stream-level flow control blocked
+		// - there's data for writing, but the stream is connection-level flow control blocked
+		if s.dataForWriting == nil {
+			return nil, false
+		}
+		isBlocked, _ := s.flowController.IsBlocked()
+		return nil, !isBlocked
 	}
 	if frame.FinBit {
 		s.finSent = true
 	} else if s.streamID != s.version.CryptoStreamID() { // TODO(#657): Flow control for the crypto stream
-		if isBlocked, offset := s.flowController.IsNewlyBlocked(); isBlocked {
+		if isBlocked, offset := s.flowController.IsBlocked(); isBlocked {
 			s.sender.queueControlFrame(&wire.StreamBlockedFrame{
 				StreamID: s.streamID,
 				Offset:   offset,
 			})
+			return frame, false
 		}
 	}
 	return frame, s.dataForWriting != nil
@@ -232,6 +242,11 @@ func (s *sendStream) handleStopSendingFrame(frame *wire.StopSendingFrame) {
 
 func (s *sendStream) handleMaxStreamDataFrame(frame *wire.MaxStreamDataFrame) {
 	s.flowController.UpdateSendWindow(frame.ByteOffset)
+	s.mutex.Lock()
+	if s.dataForWriting != nil {
+		s.sender.onHasStreamData(s.streamID)
+	}
+	s.mutex.Unlock()
 }
 
 // must be called after locking the mutex

send_stream_test.go

@@ -45,7 +45,7 @@ var _ = Describe("Send Stream", func() {
 			mockSender.EXPECT().onHasStreamData(streamID)
 			mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(9999))
 			mockFC.EXPECT().AddBytesSent(protocol.ByteCount(6))
-			mockFC.EXPECT().IsNewlyBlocked()
+			mockFC.EXPECT().IsBlocked()
 			done := make(chan struct{})
 			go func() {
 				defer GinkgoRecover()
@@ -74,7 +74,7 @@ var _ = Describe("Send Stream", func() {
 			frameHeaderLen := protocol.ByteCount(4)
 			mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(9999)).Times(2)
 			mockFC.EXPECT().AddBytesSent(gomock.Any() /* protocol.ByteCount(3)*/).Times(2)
-			mockFC.EXPECT().IsNewlyBlocked().Times(2)
+			mockFC.EXPECT().IsBlocked().Times(2)
 			done := make(chan struct{})
 			go func() {
 				defer GinkgoRecover()
@@ -112,7 +112,7 @@ var _ = Describe("Send Stream", func() {
 			mockSender.EXPECT().onHasStreamData(streamID)
 			mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(9999)).Times(2)
 			mockFC.EXPECT().AddBytesSent(gomock.Any()).Times(2)
-			mockFC.EXPECT().IsNewlyBlocked().Times(2)
+			mockFC.EXPECT().IsBlocked().Times(2)
 			done := make(chan struct{})
 			go func() {
 				defer GinkgoRecover()
@@ -142,7 +142,7 @@ var _ = Describe("Send Stream", func() {
 			mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(9999)).Times(2)
 			mockFC.EXPECT().AddBytesSent(protocol.ByteCount(1))
 			mockFC.EXPECT().AddBytesSent(protocol.ByteCount(2))
-			mockFC.EXPECT().IsNewlyBlocked().Times(2)
+			mockFC.EXPECT().IsBlocked().Times(2)
 			s := []byte("foo")
 			go func() {
 				defer GinkgoRecover()
@@ -178,7 +178,27 @@ var _ = Describe("Send Stream", func() {
 			Expect(str.Context().Done()).To(BeClosed())
 		})
 
-		Context("adding BLOCKED", func() {
+		Context("flow control blocking", func() {
+			It("returns nil when it is blocked", func() {
+				mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(0))
+				mockFC.EXPECT().IsBlocked().Return(true, protocol.ByteCount(10))
+				mockSender.EXPECT().onHasStreamData(streamID)
+				done := make(chan struct{})
+				go func() {
+					defer GinkgoRecover()
+					_, err := str.Write([]byte("foobar"))
+					Expect(err).ToNot(HaveOccurred())
+					close(done)
+				}()
+				Consistently(done).ShouldNot(BeClosed())
+				f, hasMoreData := str.popStreamFrame(1000)
+				Expect(f).To(BeNil())
+				Expect(hasMoreData).To(BeFalse())
+				// make the Write go routine return
+				str.closeForShutdown(nil)
+				Eventually(done).Should(BeClosed())
+			})
+
 			It("queues a BLOCKED frame if the stream is flow control blocked", func() {
 				mockSender.EXPECT().onHasStreamData(streamID)
 				mockSender.EXPECT().queueControlFrame(&wire.StreamBlockedFrame{
@@ -188,7 +208,7 @@ var _ = Describe("Send Stream", func() {
 				mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(9999))
 				mockFC.EXPECT().AddBytesSent(protocol.ByteCount(6))
 				// don't use offset 6 here, to make sure the BLOCKED frame contains the number returned by the flow controller
-				mockFC.EXPECT().IsNewlyBlocked().Return(true, protocol.ByteCount(10))
+				mockFC.EXPECT().IsBlocked().Return(true, protocol.ByteCount(10))
 				done := make(chan struct{})
 				go func() {
 					defer GinkgoRecover()
@@ -204,11 +224,34 @@ var _ = Describe("Send Stream", func() {
 				Eventually(done).Should(BeClosed())
 			})
 
+			It("says that it doesn't have any more data, when it is flow control blocked", func() {
+				mockSender.EXPECT().onHasStreamData(streamID)
+				mockSender.EXPECT().queueControlFrame(gomock.Any())
+				mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(9999))
+				mockFC.EXPECT().AddBytesSent(gomock.Any())
+				mockFC.EXPECT().IsBlocked().Return(true, protocol.ByteCount(10))
+				done := make(chan struct{})
+				go func() {
+					defer GinkgoRecover()
+					_, err := str.Write(bytes.Repeat([]byte{0}, 100))
+					Expect(err).ToNot(HaveOccurred())
+					close(done)
+				}()
+				Eventually(func() *wire.StreamFrame {
+					f, hasMoreData := str.popStreamFrame(50)
+					Expect(hasMoreData).To(BeFalse())
+					return f
+				}).ShouldNot(BeNil())
+				// make the Write go routine return
+				str.closeForShutdown(nil)
+				Eventually(done).Should(BeClosed())
+			})
+
 			It("doesn't queue a BLOCKED frame if the stream is flow control blocked, but the frame popped has the FIN bit set", func() {
 				mockSender.EXPECT().onHasStreamData(streamID).Times(2) // once for the Write, once for the Close
 				mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(9999))
 				mockFC.EXPECT().AddBytesSent(protocol.ByteCount(6))
-				// don't EXPECT a call to mockFC.IsNewlyBlocked
+				// don't EXPECT a call to mockFC.IsBlocked
 				// don't EXPECT a call to mockSender.queueControlFrame
 				done := make(chan struct{})
 				go func() {
@@ -251,7 +294,7 @@ var _ = Describe("Send Stream", func() {
 				mockSender.EXPECT().onHasStreamData(streamID)
 				mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(10000)).AnyTimes()
 				mockFC.EXPECT().AddBytesSent(gomock.Any())
-				mockFC.EXPECT().IsNewlyBlocked()
+				mockFC.EXPECT().IsBlocked()
 				deadline := time.Now().Add(scaleDuration(50 * time.Millisecond))
 				str.SetWriteDeadline(deadline)
 				var n int
@@ -277,7 +320,7 @@ var _ = Describe("Send Stream", func() {
 				mockSender.EXPECT().onHasStreamData(streamID)
 				mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(10000)).AnyTimes()
 				mockFC.EXPECT().AddBytesSent(gomock.Any())
-				mockFC.EXPECT().IsNewlyBlocked()
+				mockFC.EXPECT().IsBlocked()
 				deadline := time.Now().Add(scaleDuration(50 * time.Millisecond))
 				str.SetWriteDeadline(deadline)
 				writeReturned := make(chan struct{})
@@ -359,7 +402,7 @@ var _ = Describe("Send Stream", func() {
 				frameHeaderLen := protocol.ByteCount(4)
 				mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(9999)).Times(2)
 				mockFC.EXPECT().AddBytesSent(gomock.Any()).Times(2)
-				mockFC.EXPECT().IsNewlyBlocked()
+				mockFC.EXPECT().IsBlocked()
 				str.dataForWriting = []byte("foobar")
 				Expect(str.Close()).To(Succeed())
 				f, _ := str.popStreamFrame(3 + frameHeaderLen)
@@ -405,7 +448,7 @@ var _ = Describe("Send Stream", func() {
 				mockSender.EXPECT().onHasStreamData(streamID)
 				mockFC.EXPECT().SendWindowSize().Return(protocol.ByteCount(9999))
 				mockFC.EXPECT().AddBytesSent(gomock.Any())
-				mockFC.EXPECT().IsNewlyBlocked()
+				mockFC.EXPECT().IsBlocked()
 				done := make(chan struct{})
 				go func() {
 					defer GinkgoRecover()
@@ -432,6 +475,34 @@ var _ = Describe("Send Stream", func() {
 		})
 	})
 
+	Context("hanlding MAX_STREAM_DATA frames", func() {
+		It("informs the flow controller", func() {
+			mockFC.EXPECT().UpdateSendWindow(protocol.ByteCount(0x1337))
+			str.handleMaxStreamDataFrame(&wire.MaxStreamDataFrame{
+				StreamID:   streamID,
+				ByteOffset: 0x1337,
+			})
+		})
+
+		It("says when it has data for sending", func() {
+			mockFC.EXPECT().UpdateSendWindow(gomock.Any())
+			mockSender.EXPECT().onHasStreamData(streamID)
+			done := make(chan struct{})
+			go func() {
+				defer GinkgoRecover()
+				_, _ = str.Write([]byte("foobar"))
+				close(done)
+			}()
+			str.handleMaxStreamDataFrame(&wire.MaxStreamDataFrame{
+				StreamID:   streamID,
+				ByteOffset: 42,
+			})
+			// make sure the Write go routine returns
+			str.closeForShutdown(nil)
+			Eventually(done).Should(BeClosed())
+		})
+	})
+
 	Context("stream cancelations", func() {
 		Context("canceling writing", func() {
 			It("queues a RST_STREAM frame", func() {
@@ -450,7 +521,7 @@ var _ = Describe("Send Stream", func() {
 				mockSender.EXPECT().queueControlFrame(gomock.Any())
 				mockFC.EXPECT().SendWindowSize().Return(protocol.MaxByteCount)
 				mockFC.EXPECT().AddBytesSent(gomock.Any())
-				mockFC.EXPECT().IsNewlyBlocked()
+				mockFC.EXPECT().IsBlocked()
 				writeReturned := make(chan struct{})
 				var n int
 				go func() {

stream_test.go

@@ -130,7 +130,7 @@ var _ = Describe("Stream", func() {
 				mockSender.EXPECT().onHasStreamData(streamID).Times(2) // once for the Write, once for the Close
 				mockFC.EXPECT().SendWindowSize().Return(protocol.MaxByteCount).AnyTimes()
 				mockFC.EXPECT().AddBytesSent(protocol.ByteCount(6))
-				mockFC.EXPECT().IsNewlyBlocked()
+				mockFC.EXPECT().IsBlocked()
 				err := str.CancelRead(1234)
 				Expect(err).ToNot(HaveOccurred())
 				writeReturned := make(chan struct{})