fix race conditions in the packet sending tests in the session

session_test.go

@@ -1004,12 +1004,10 @@ var _ = Describe("Session", func() {
 	})
 
 	Context("sending packets", func() {
+		var sessionDone chan struct{}
+
 		BeforeEach(func() {
-			cryptoSetup.EXPECT().RunHandshake().MaxTimes(1)
-			go func() {
-				defer GinkgoRecover()
-				sess.run()
-			}()
+			sessionDone = make(chan struct{})
 		})
 
 		AfterEach(func() {
@@ -1021,10 +1019,21 @@ var _ = Describe("Session", func() {
 			qlogger.EXPECT().Export()
 			sess.shutdown()
 			Eventually(sess.Context().Done()).Should(BeClosed())
+			Eventually(sessionDone).Should(BeClosed())
 		})
 
+		runSession := func() {
+			go func() {
+				defer GinkgoRecover()
+				cryptoSetup.EXPECT().RunHandshake().MaxTimes(1)
+				sess.run()
+				close(sessionDone)
+			}()
+		}
+
 		It("sends packets", func() {
 			sess.handshakeConfirmed = true
+			runSession()
 			p := getPacket(1)
 			packer.EXPECT().PackPacket().Return(p, nil)
 			sess.receivedPacketHandler.ReceivedPacket(0x035e, protocol.Encryption1RTT, time.Now(), true)
@@ -1037,6 +1046,7 @@ var _ = Describe("Session", func() {
 
 		It("doesn't send packets if there's nothing to send", func() {
 			sess.handshakeConfirmed = true
+			runSession()
 			packer.EXPECT().PackPacket().Return(nil, nil)
 			sess.receivedPacketHandler.ReceivedPacket(0x035e, protocol.Encryption1RTT, time.Now(), true)
 			sent, err := sess.sendPacket()
@@ -1050,6 +1060,7 @@ var _ = Describe("Session", func() {
 			sph.EXPECT().SendMode().Return(ackhandler.SendAck)
 			sph.EXPECT().ShouldSendNumPackets().Return(1000)
 			packer.EXPECT().MaybePackAckPacket(false)
+			runSession()
 			sess.sentPacketHandler = sph
 			Expect(sess.sendPackets()).To(Succeed())
 		})
@@ -1061,6 +1072,7 @@ var _ = Describe("Session", func() {
 			p := getPacket(1)
 			packer.EXPECT().PackPacket().Return(p, nil)
 			sess.connFlowController = fc
+			runSession()
 			mconn.EXPECT().Write(gomock.Any())
 			qlogger.EXPECT().SentPacket(p.header, p.length, nil, []wire.Frame{})
 			sent, err := sess.sendPacket()
@@ -1075,6 +1087,7 @@ var _ = Describe("Session", func() {
 			sph.EXPECT().GetLossDetectionTimeout().AnyTimes()
 			sph.EXPECT().SendMode().Return(ackhandler.SendNone)
 			sess.sentPacketHandler = sph
+			runSession()
 			Expect(sess.sendPackets()).To(Succeed())
 		})
 
@@ -1112,6 +1125,7 @@ var _ = Describe("Session", func() {
 						Expect(packet.PacketNumber).To(Equal(protocol.PacketNumber(123)))
 					})
 					sess.sentPacketHandler = sph
+					runSession()
 					mconn.EXPECT().Write(gomock.Any())
 					qlogger.EXPECT().SentPacket(p.header, p.length, gomock.Any(), gomock.Any())
 					Expect(sess.sendPackets()).To(Succeed())
@@ -1130,6 +1144,7 @@ var _ = Describe("Session", func() {
 						Expect(packet.PacketNumber).To(Equal(protocol.PacketNumber(123)))
 					})
 					sess.sentPacketHandler = sph
+					runSession()
 					mconn.EXPECT().Write(gomock.Any())
 					qlogger.EXPECT().SentPacket(p.header, p.length, gomock.Any(), gomock.Any())
 					Expect(sess.sendPackets()).To(Succeed())