Landing Recent QUIC changes until 4/22/2016 14:55 UTC

net/quic/quic_connection.cc

Index: net/quic/quic_connection.cc
diff --git a/net/quic/quic_connection.cc b/net/quic/quic_connection.cc
index 1d7f3e5d15b5e59dcb0f3ac093c48b5bb80b823d..5c633d3c695a97e5113d769a511ba3e17c12ed34 100644
--- a/net/quic/quic_connection.cc
+++ b/net/quic/quic_connection.cc
@@ -69,6 +69,10 @@ const QuicPacketCount kDefaultRetransmittablePacketsBeforeAck = 2;
 const QuicPacketCount kMinReceivedBeforeAckDecimation = 100;
 // Wait for up to 10 retransmittable packets before sending an ack.
 const QuicPacketCount kMaxRetransmittablePacketsBeforeAck = 10;
+// One quarter RTT delay when doing ack decimation.
+const float kAckDecimationDelay = 0.25;
+// One eighth RTT delay when doing ack decimation.
+const float kShortAckDecimationDelay = 0.125;
 
 bool Near(QuicPacketNumber a, QuicPacketNumber b) {
   QuicPacketNumber delta = (a > b) ? a - b : b - a;
@@ -246,6 +250,7 @@ QuicConnection::QuicConnection(QuicConnectionId connection_id,
       num_packets_received_since_last_ack_sent_(0),
       stop_waiting_count_(0),
       ack_mode_(TCP_ACKING),
+      ack_decimation_delay_(kAckDecimationDelay),
       delay_setting_retransmission_alarm_(false),
       pending_retransmission_alarm_(false),
       defer_send_in_response_to_packets_(false),
@@ -372,10 +377,17 @@ void QuicConnection::SetFromConfig(const QuicConfig& config) {
   if (config.HasClientSentConnectionOption(kACKD, perspective_)) {
     ack_mode_ = ACK_DECIMATION;
   }
-  if (FLAGS_quic_ack_decimation2 &&
-      config.HasClientSentConnectionOption(kAKD2, perspective_)) {
+  if (config.HasClientSentConnectionOption(kAKD2, perspective_)) {
     ack_mode_ = ACK_DECIMATION_WITH_REORDERING;
   }
+  if (config.HasClientSentConnectionOption(kAKD3, perspective_)) {
+    ack_mode_ = ACK_DECIMATION;
+    ack_decimation_delay_ = kShortAckDecimationDelay;
+  }
+  if (config.HasClientSentConnectionOption(kAKD4, perspective_)) {
+    ack_mode_ = ACK_DECIMATION_WITH_REORDERING;
+    ack_decimation_delay_ = kShortAckDecimationDelay;
+  }
   if (FLAGS_quic_enable_rto_timeout &&
       config.HasClientSentConnectionOption(k5RTO, perspective_)) {
     close_connection_after_five_rtos_ = true;
@@ -764,6 +776,14 @@ bool QuicConnection::OnStopWaitingFrame(const QuicStopWaitingFrame& frame) {
   return connected_;
 }
 
+bool QuicConnection::OnPaddingFrame(const QuicPaddingFrame& frame) {
+  DCHECK(connected_);
+  if (debug_visitor_ != nullptr) {
+    debug_visitor_->OnPaddingFrame(frame);
+  }
+  return true;
+}
+
 bool QuicConnection::OnPingFrame(const QuicPingFrame& frame) {
   DCHECK(connected_);
   if (debug_visitor_ != nullptr) {
@@ -998,7 +1018,8 @@ void QuicConnection::MaybeQueueAck(bool was_missing) {
         // Wait the minimum of a quarter min_rtt and the delayed ack time.
         QuicTime::Delta ack_delay = QuicTime::Delta::Min(
             sent_packet_manager_.DelayedAckTime(),
-            sent_packet_manager_.GetRttStats()->min_rtt().Multiply(0.25));
+            sent_packet_manager_.GetRttStats()->min_rtt().Multiply(
+                ack_decimation_delay_));
         ack_alarm_->Set(clock_->ApproximateNow().Add(ack_delay));
       }
     } else {
@@ -1790,8 +1811,12 @@ void QuicConnection::SendAck() {
 }
 
 void QuicConnection::OnRetransmissionTimeout() {
-  if (!sent_packet_manager_.HasUnackedPackets()) {
-    return;
+  if (FLAGS_quic_always_has_unacked_packets_on_timeout) {
+    DCHECK(sent_packet_manager_.HasUnackedPackets());
+  } else {
+    if (!sent_packet_manager_.HasUnackedPackets()) {
+      return;
+    }
   }
 
   if (close_connection_after_five_rtos_ &&