commit bc9f56fa7bedb7b95a3e80952c2a617b950aafe7
author fayang <fayang@google.com> Fri Jun 19 03:49:22 2020 -0700
committer Copybara-Service <copybara-worker@google.com> Fri Jun 19 03:49:56 2020 -0700
tree e3985ffe19ddf222068901dc3c7fe9db7e17f53b
parent 37b2e1806f4a8aebd093c41df3baa70153a1c5ad

In quic, add a connection option to enable more aggressive pto timeout before any rtt sample is available. not protected.

PiperOrigin-RevId: 317280920
Change-Id: Ia607d240d11d3365eef0518c76fb9d5e86c1d55e

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 d74a487..eeeddf2 100644
--- a/quic/core/quic_sent_packet_manager.cc
+++ b/quic/core/quic_sent_packet_manager.cc
@@ -107,7 +107,8 @@
       one_rtt_packet_acked_(false),
       one_rtt_packet_sent_(false),
       first_pto_srtt_multiplier_(0),
-      use_standard_deviation_for_pto_(false) {
+      use_standard_deviation_for_pto_(false),
+      pto_multiplier_without_rtt_samples_(3) {
   SetSendAlgorithm(congestion_control_type);
   if (pto_enabled_) {
     QUIC_RELOADABLE_FLAG_COUNT_N(quic_default_on_pto, 1, 2);
@@ -197,6 +198,9 @@
     } else if (config.HasClientSentConnectionOption(kPLE2, perspective)) {
       first_pto_srtt_multiplier_ = 1.5;
     }
+    if (config.HasClientSentConnectionOption(kAPTO, perspective)) {
+      pto_multiplier_without_rtt_samples_ = 1.5;
+    }
     if (config.HasClientSentConnectionOption(kPSDA, perspective)) {
       use_standard_deviation_for_pto_ = true;
       rtt_stats_.EnableStandardDeviationCalculation();
@@ -1230,8 +1234,9 @@
   if (rtt_stats_.smoothed_rtt().IsZero()) {
     // Respect kMinHandshakeTimeoutMs to avoid a potential amplification attack.
     QUIC_BUG_IF(rtt_stats_.initial_rtt().IsZero());
-    return std::max(3 * rtt_stats_.initial_rtt(),
-                    QuicTime::Delta::FromMilliseconds(kMinHandshakeTimeoutMs)) *
+    return std::max(
+               pto_multiplier_without_rtt_samples_ * rtt_stats_.initial_rtt(),
+               QuicTime::Delta::FromMilliseconds(kMinHandshakeTimeoutMs)) *
            (1 << consecutive_pto_count_);
   }
   const QuicTime::Delta rtt_var = use_standard_deviation_for_pto_