QUIC: Only send a new SCUP if enough packets have been sent since the

net/tools/quic/quic_server_session.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/tools/quic/quic_server_session.h"
 
 #include "base/logging.h"
 #include "net/quic/crypto/source_address_token.h"
 #include "net/quic/quic_connection.h"
 #include "net/quic/quic_flags.h"
 #include "net/quic/reliable_quic_stream.h"
 #include "net/tools/quic/quic_spdy_server_stream.h"
 
 namespace net {
 namespace tools {
 
 QuicServerSession::QuicServerSession(const QuicConfig& config,
                                      QuicConnection* connection,
                                      QuicServerSessionVisitor* visitor)
     : QuicSession(connection, config),
       visitor_(visitor),
       bandwidth_estimate_sent_to_client_(QuicBandwidth::Zero()),
-      last_server_config_update_time_(QuicTime::Zero()) {}
+      last_scup_time_(QuicTime::Zero()),
+      last_scup_sequence_number_(0) {}
 
 QuicServerSession::~QuicServerSession() {}
 
 void QuicServerSession::InitializeSession(
     const QuicCryptoServerConfig& crypto_config) {
   QuicSession::InitializeSession();
   crypto_stream_.reset(CreateQuicCryptoServerStream(crypto_config));
 }
 
 QuicCryptoServerStream* QuicServerSession::CreateQuicCryptoServerStream(
@@ skipping 28 matching lines @@
   QuicSession::OnWriteBlocked();
   visitor_->OnWriteBlocked(connection());
 }
 
 void QuicServerSession::OnCongestionWindowChange(QuicTime now) {
   if (connection()->version() <= QUIC_VERSION_21) {
     return;
   }
 
   // If not enough time has passed since the last time we sent an update to the
-  // client, then return early.
+  // client, or not enough packets have been sent, then return early.
   const QuicSentPacketManager& sent_packet_manager =
       connection()->sent_packet_manager();
   int64 srtt_ms =
       sent_packet_manager.GetRttStats()->SmoothedRtt().ToMilliseconds();
-  int64 now_ms = now.Subtract(last_server_config_update_time_).ToMilliseconds();
+  int64 now_ms = now.Subtract(last_scup_time_).ToMilliseconds();
+  int64 packets_since_last_scup =
+      connection()->sequence_number_of_last_sent_packet() -
+      last_scup_sequence_number_;
   if (now_ms < (kMinIntervalBetweenServerConfigUpdatesRTTs * srtt_ms) ||
-      now_ms < kMinIntervalBetweenServerConfigUpdatesMs) {
+      now_ms < kMinIntervalBetweenServerConfigUpdatesMs ||
+      packets_since_last_scup < kMinPacketsBetweenServerConfigUpdates) {
     return;
   }
 
   // If the bandwidth recorder does not have a valid estimate, return early.
   const QuicSustainedBandwidthRecorder& bandwidth_recorder =
       sent_packet_manager.SustainedBandwidthRecorder();
   if (!bandwidth_recorder.HasEstimate()) {
     return;
   }
 
@@ skipping 38 matching lines @@
       bandwidth_recorder.EstimateRecordedDuringSlowStart()
           ? CachedNetworkParameters::SLOW_START
           : CachedNetworkParameters::CONGESTION_AVOIDANCE);
   cached_network_params.set_timestamp(
       connection()->clock()->WallNow().ToUNIXSeconds());
   if (!serving_region_.empty()) {
     cached_network_params.set_serving_region(serving_region_);
   }
 
   crypto_stream_->SendServerConfigUpdate(&cached_network_params);
-  last_server_config_update_time_ = now;
+  last_scup_time_ = now;
+  last_scup_sequence_number_ =
+      connection()->sequence_number_of_last_sent_packet();
 }
 
 bool QuicServerSession::ShouldCreateIncomingDataStream(QuicStreamId id) {
   if (id % 2 == 0) {
     DVLOG(1) << "Invalid incoming even stream_id:" << id;
     connection()->SendConnectionClose(QUIC_INVALID_STREAM_ID);
     return false;
   }
   if (GetNumOpenStreams() >= get_max_open_streams()) {
     DVLOG(1) << "Failed to create a new incoming stream with id:" << id
@@ skipping 18 matching lines @@
   DLOG(ERROR) << "Server push not yet supported";
   return nullptr;
 }
 
 QuicCryptoServerStream* QuicServerSession::GetCryptoStream() {
   return crypto_stream_.get();
 }
 
 }  // namespace tools
 }  // namespace net