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
diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 1ad2ddb..66b3dd4 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -2422,6 +2422,13 @@
void QuicConnection::OnRetransmissionTimeout() {
DCHECK(!sent_packet_manager_.unacked_packets().empty());
+ const QuicPacketNumber previous_created_packet_number =
+ packet_generator_.packet_number();
+ const size_t previous_crypto_retransmit_count =
+ stats_.crypto_retransmit_count;
+ const size_t previous_loss_timeout_count = stats_.loss_timeout_count;
+ const size_t previous_tlp_count = stats_.tlp_count;
+ const size_t pervious_rto_count = stats_.rto_count;
if (close_connection_after_five_rtos_ &&
sent_packet_manager_.GetConsecutiveRtoCount() >= 4) {
// Close on the 5th consecutive RTO, so after 4 previous RTOs have occurred.
@@ -2446,6 +2453,29 @@
WriteIfNotBlocked();
}
+ if (sent_packet_manager_.fix_rto_retransmission()) {
+ // Making sure at least one packet is created when retransmission timer
+ // fires in TLP, RTO or HANDSHAKE mode. It is possible that loss algorithm
+ // invokes timer based loss but the packet does not need to be
+ // retransmitted.
+ QUIC_BUG_IF(stats_.loss_timeout_count == previous_loss_timeout_count &&
+ packet_generator_.packet_number() ==
+ previous_created_packet_number)
+ << "previous_crypto_retransmit_count: "
+ << previous_crypto_retransmit_count
+ << ", crypto_retransmit_count: " << stats_.crypto_retransmit_count
+ << ", previous_loss_timeout_count: " << previous_loss_timeout_count
+ << ", loss_timeout_count: " << stats_.loss_timeout_count
+ << ", previous_tlp_count: " << previous_tlp_count
+ << ", tlp_count: " << stats_.tlp_count
+ << ", pervious_rto_count: " << pervious_rto_count
+ << ", rto_count: " << stats_.rto_count
+ << ", previous_created_packet_number: "
+ << previous_created_packet_number
+ << ", packet_number: " << packet_generator_.packet_number()
+ << ", session has data to write: " << visitor_->WillingAndAbleToWrite();
+ }
+
// Ensure the retransmission alarm is always set if there are unacked packets
// and nothing waiting to be sent.
// This happens if the loss algorithm invokes a timer based loss, but the
