commit a29eb2428037aa7acbbee9f4fce785a054ce9a7c
author fayang <fayang@google.com> Tue Jul 16 12:25:38 2019 -0700
committer Copybara-Service <copybara-worker@google.com> Tue Jul 16 13:50:49 2019 -0700
tree c348cfdcaf862d89c15e17b1aa9b889125d126ad
parent e66b62d8a9db43e92060ba3f0954ae0d5ef9716c

gfe-relnote: In QUIC, when RTO fires and there is no packet to be RTOed, let connection send data. Protected by gfe2_reloadable_flag_quic_fix_rto_retransmission.

PiperOrigin-RevId: 258417558
Change-Id: I75267afafee6834f7b6f4cd59d08bdc036c3bd58

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 a4aa08e..a93115b 100644
--- a/quic/core/quic_sent_packet_manager.cc
+++ b/quic/core/quic_sent_packet_manager.cc
@@ -120,10 +120,15 @@
       loss_removes_from_inflight_(
           GetQuicReloadableFlag(quic_loss_removes_from_inflight)),
       ignore_tlpr_if_no_pending_stream_data_(
-          GetQuicReloadableFlag(quic_ignore_tlpr_if_no_pending_stream_data)) {
+          GetQuicReloadableFlag(quic_ignore_tlpr_if_no_pending_stream_data)),
+      fix_rto_retransmission_(
+          GetQuicReloadableFlag(quic_fix_rto_retransmission)) {
   if (loss_removes_from_inflight_) {
     QUIC_RELOADABLE_FLAG_COUNT(quic_loss_removes_from_inflight);
   }
+  if (fix_rto_retransmission_) {
+    QUIC_RELOADABLE_FLAG_COUNT(quic_fix_rto_retransmission);
+  }
   SetSendAlgorithm(congestion_control_type);
 }
 
@@ -803,7 +808,7 @@
     if (session_decides_what_to_write()) {
       has_retransmissions = it->state != OUTSTANDING;
     }
-    if (it->in_flight && !has_retransmissions &&
+    if (!fix_rto_retransmission_ && it->in_flight && !has_retransmissions &&
         !unacked_packets_.HasRetransmittableFrames(*it)) {
       // Log only for non-retransmittable data.
       // Retransmittable data is marked as lost during loss detection, and will
@@ -825,6 +830,13 @@
     for (QuicPacketNumber retransmission : retransmissions) {
       MarkForRetransmission(retransmission, RTO_RETRANSMISSION);
     }
+    if (fix_rto_retransmission_ && retransmissions.empty()) {
+      QUIC_BUG_IF(pending_timer_transmission_count_ != 0);
+      // No packets to be RTO retransmitted, raise up a credit to allow
+      // connection to send.
+      QUIC_CODE_COUNT(no_packets_to_be_rto_retransmitted);
+      pending_timer_transmission_count_ = 1;
+    }
   }
 }