don't pace when congestion limited

quic-go · Jul 2, 2019 · 1a272cb · 1a272cb
1 parent 3dcbaee
commit 1a272cb
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diff --git a/internal/congestion/cubic_sender.go b/internal/congestion/cubic_sender.go
@@ -87,6 +87,9 @@ func NewCubicSender(clock Clock, rttStats *RTTStats, reno bool, initialCongestio
 
 // TimeUntilSend returns when the next packet should be sent.
 func (c *cubicSender) TimeUntilSend(bytesInFlight protocol.ByteCount) time.Duration {
+	if !c.CanSend(bytesInFlight) {
+		return utils.InfDuration
+	}
 	if !c.noPRR && c.InRecovery() {
 		// PRR is used when in recovery.
 		if c.prr.CanSend(c.GetCongestionWindow(), bytesInFlight, c.GetSlowStartThreshold()) {

diff --git a/internal/congestion/cubic_sender_test.go b/internal/congestion/cubic_sender_test.go
@@ -107,6 +107,12 @@ var _ = Describe("Cubic Sender", func() {
 		Expect(delay).ToNot(Equal(utils.InfDuration))
 	})
 
+	It("stops pacing when congestion limited", func() {
+		bytesInFlight := sender.GetCongestionWindow()
+		Expect(sender.CanSend(bytesInFlight)).To(BeFalse())
+		Expect(sender.TimeUntilSend(bytesInFlight)).To(Equal(utils.InfDuration))
+	})
+
 	It("application limited slow start", func() {
 		// Send exactly 10 packets and ensure the CWND ends at 14 packets.
 		const numberOfAcks = 5