commit 75db4342f7f19ab6161a1ef4465e7e042487868a
author fayang <fayang@google.com> Mon Nov 04 13:29:14 2019 -0800
committer Copybara-Service <copybara-worker@google.com> Mon Nov 04 13:29:56 2019 -0800
tree a35282e9a94d0b882ead7500c67d3ee6a9d72074
parent 053453b6de556d8fb1f9c96d973cff094b4e17c3

gfe-relnote: In QUIC, add a connection option to use 2 * rttvar when calculating PTO timeout. Protected by existing gfe2_reloadable_flag_quic_enable_pto.

PiperOrigin-RevId: 278451908
Change-Id: I5f68cad58734bd52e70efce51eefd84646050cac

quic/core/quic_sent_packet_manager.cc

diff --git a/quic/core/quic_sent_packet_manager.cc b/quic/core/quic_sent_packet_manager.cc
index f9ec1c0..deec82f 100644
--- a/quic/core/quic_sent_packet_manager.cc
+++ b/quic/core/quic_sent_packet_manager.cc
@@ -105,6 +105,7 @@
       skip_packet_number_for_pto_(false),
       always_include_max_ack_delay_for_pto_timeout_(true),
       pto_exponential_backoff_start_point_(0),
+      pto_rttvar_multiplier_(4),
       neuter_handshake_packets_once_(
           GetQuicReloadableFlag(quic_neuter_handshake_packets_once)) {
   SetSendAlgorithm(congestion_control_type);
@@ -151,12 +152,12 @@
   if (GetQuicReloadableFlag(quic_enable_pto)) {
     if (config.HasClientSentConnectionOption(k2PTO, perspective)) {
       pto_enabled_ = true;
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 2, 7);
+      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 2, 8);
     }
     if (config.HasClientSentConnectionOption(k1PTO, perspective)) {
       pto_enabled_ = true;
       max_probe_packets_per_pto_ = 1;
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 1, 7);
+      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 1, 8);
     }
   }
 
@@ -174,17 +175,21 @@
 
   if (pto_enabled_) {
     if (config.HasClientSentConnectionOption(kPTOA, perspective)) {
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 5, 7);
+      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 5, 8);
       always_include_max_ack_delay_for_pto_timeout_ = false;
     }
     if (config.HasClientSentConnectionOption(kPEB1, perspective)) {
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 6, 7);
+      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 6, 8);
       StartExponentialBackoffAfterNthPto(1);
     }
     if (config.HasClientSentConnectionOption(kPEB2, perspective)) {
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 7, 7);
+      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 7, 8);
       StartExponentialBackoffAfterNthPto(2);
     }
+    if (config.HasClientSentConnectionOption(kPVS1, perspective)) {
+      QUIC_RELOADABLE_FLAG_COUNT_N(quic_enable_pto, 8, 8);
+      pto_rttvar_multiplier_ = 2;
+    }
   }
 
   // Configure congestion control.
@@ -1045,7 +1050,7 @@
   }
   const QuicTime::Delta pto_delay =
       rtt_stats_.smoothed_rtt() +
-      std::max(4 * rtt_stats_.mean_deviation(),
+      std::max(pto_rttvar_multiplier_ * rtt_stats_.mean_deviation(),
                QuicTime::Delta::FromMilliseconds(1)) +
       (ShouldAddMaxAckDelay() ? peer_max_ack_delay_ : QuicTime::Delta::Zero());
   return pto_delay * (1 << (consecutive_pto_count_ -