Adds an alarm for sending a QUIC FEC packet.

net/quic/quic_connection.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/quic/quic_connection.h"
 
 #include <string.h>
 #include <sys/types.h>
 
 #include <algorithm>
 #include <iterator>
 #include <limits>
 #include <memory>
 #include <set>
 #include <utility>
 
 #include "base/debug/stack_trace.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/strings/stringprintf.h"
 #include "net/base/net_errors.h"
 #include "net/quic/crypto/quic_decrypter.h"
 #include "net/quic/crypto/quic_encrypter.h"
 #include "net/quic/iovector.h"
 #include "net/quic/quic_bandwidth.h"
 #include "net/quic/quic_config.h"
 #include "net/quic/quic_fec_group.h"
 #include "net/quic/quic_flags.h"
+#include "net/quic/quic_packet_generator.h"
 #include "net/quic/quic_utils.h"
 
 using base::StringPiece;
 using base::StringPrintf;
 using base::hash_map;
 using base::hash_set;
 using std::list;
 using std::make_pair;
 using std::max;
 using std::min;
@@ skipping 114 matching lines @@
     connection_->SendPing();
     return QuicTime::Zero();
   }
 
  private:
   QuicConnection* connection_;
 
   DISALLOW_COPY_AND_ASSIGN(PingAlarm);
 };
 
+// This alarm may be scheduled when an FEC protected packet is sent out.
+class FecAlarm : public QuicAlarm::Delegate {
+ public:
+  explicit FecAlarm(QuicPacketGenerator* packet_generator)
+      : packet_generator_(packet_generator) {}
+
+  QuicTime OnAlarm() override {
+    packet_generator_->OnFecTimeout();
+    return QuicTime::Zero();
+  }
+
+ private:
+  QuicPacketGenerator* packet_generator_;
+
+  DISALLOW_COPY_AND_ASSIGN(FecAlarm);
+};
+
 }  // namespace
 
 QuicConnection::QueuedPacket::QueuedPacket(SerializedPacket packet,
                                            EncryptionLevel level)
     : serialized_packet(packet),
       encryption_level(level),
       transmission_type(NOT_RETRANSMISSION),
       original_sequence_number(0) {
 }
 
@@ skipping 45 matching lines @@
       ack_queued_(false),
       num_packets_received_since_last_ack_sent_(0),
       stop_waiting_count_(0),
       ack_alarm_(helper->CreateAlarm(new AckAlarm(this))),
       retransmission_alarm_(helper->CreateAlarm(new RetransmissionAlarm(this))),
       send_alarm_(helper->CreateAlarm(new SendAlarm(this))),
       resume_writes_alarm_(helper->CreateAlarm(new SendAlarm(this))),
       timeout_alarm_(helper->CreateAlarm(new TimeoutAlarm(this))),
       ping_alarm_(helper->CreateAlarm(new PingAlarm(this))),
       packet_generator_(connection_id_, &framer_, random_generator_, this),
+      fec_alarm_(helper->CreateAlarm(new FecAlarm(&packet_generator_))),
       idle_network_timeout_(QuicTime::Delta::Infinite()),
       overall_connection_timeout_(QuicTime::Delta::Infinite()),
       time_of_last_received_packet_(clock_->ApproximateNow()),
       time_of_last_sent_new_packet_(clock_->ApproximateNow()),
       sequence_number_of_last_sent_packet_(0),
       sent_packet_manager_(
           is_server,
           clock_,
           &stats_,
           FLAGS_quic_use_bbr_congestion_control ? kBBR : kCubic,
@@ skipping 79 matching lines @@
 
 void QuicConnection::OnError(QuicFramer* framer) {
   // Packets that we can not or have not decrypted are dropped.
   // TODO(rch): add stats to measure this.
   if (!connected_ || last_packet_decrypted_ == false) {
     return;
   }
   SendConnectionCloseWithDetails(framer->error(), framer->detailed_error());
 }
 
+void QuicConnection::MaybeSetFecAlarm(
+    QuicPacketSequenceNumber sequence_number) {
+  if (fec_alarm_->IsSet()) {
+    return;
+  }
+  QuicTime::Delta timeout = packet_generator_.GetFecTimeout(sequence_number);
+  if (!timeout.IsInfinite()) {
+    fec_alarm_->Set(clock_->ApproximateNow().Add(timeout));
+  }
+}
+
 void QuicConnection::OnPacket() {
   DCHECK(last_stream_frames_.empty() &&
          last_ack_frames_.empty() &&
          last_congestion_frames_.empty() &&
          last_stop_waiting_frames_.empty() &&
          last_rst_frames_.empty() &&
          last_goaway_frames_.empty() &&
          last_window_update_frames_.empty() &&
          last_blocked_frames_.empty() &&
          last_ping_frames_.empty() &&
@@ skipping 1154 matching lines @@
                                  packet->original_sequence_number,
                                  packet->encryption_level,
                                  packet->transmission_type,
                                  *encrypted,
                                  packet_send_time);
   }
   if (packet->transmission_type == NOT_RETRANSMISSION) {
     time_of_last_sent_new_packet_ = packet_send_time;
   }
   SetPingAlarm();
+  MaybeSetFecAlarm(sequence_number);
   DVLOG(1) << ENDPOINT << "time "
            << (FLAGS_quic_record_send_time_before_write ?
                "we began writing " : "we finished writing ")
            << "last sent packet: "
            << packet_send_time.ToDebuggingValue();
 
   // TODO(ianswett): Change the sequence number length and other packet creator
   // options by a more explicit API than setting a struct value directly,
   // perhaps via the NetworkChangeVisitor.
   packet_generator_.UpdateSequenceNumberLength(
@@ skipping 79 matching lines @@
     SetDefaultEncryptionLevel(ENCRYPTION_FORWARD_SECURE);
   }
   if (serialized_packet.retransmittable_frames) {
     serialized_packet.retransmittable_frames->
         set_encryption_level(encryption_level_);
 
     if (FLAGS_quic_ack_notifier_informed_on_serialized) {
       sent_packet_manager_.OnSerializedPacket(serialized_packet);
     }
   }
+  if (serialized_packet.packet->is_fec_packet() && fec_alarm_->IsSet()) {
+    // If an FEC packet is serialized with the FEC alarm set, cancel the alarm.
+    fec_alarm_->Cancel();
+  }
   SendOrQueuePacket(QueuedPacket(serialized_packet, encryption_level_));
 }
 
 void QuicConnection::OnCongestionWindowChange() {
   packet_generator_.OnCongestionWindowChange(
       sent_packet_manager_.EstimateMaxPacketsInFlight(max_packet_length()));
   visitor_->OnCongestionWindowChange(clock_->ApproximateNow());
 }
 
 void QuicConnection::OnRttChange() {
@@ skipping 278 matching lines @@
   }
   connected_ = false;
   if (debug_visitor_.get() != nullptr) {
     debug_visitor_->OnConnectionClosed(error, from_peer);
   }
   visitor_->OnConnectionClosed(error, from_peer);
   // Cancel the alarms so they don't trigger any action now that the
   // connection is closed.
   ack_alarm_->Cancel();
   ping_alarm_->Cancel();
+  fec_alarm_->Cancel();
   resume_writes_alarm_->Cancel();
   retransmission_alarm_->Cancel();
   send_alarm_->Cancel();
   timeout_alarm_->Cancel();
 }
 
 void QuicConnection::SendGoAway(QuicErrorCode error,
                                 QuicStreamId last_good_stream_id,
                                 const string& reason) {
   DVLOG(1) << ENDPOINT << "Going away with error "
@@ skipping 202 matching lines @@
   }
   for (size_t i = 0; i < retransmittable_frames->frames().size(); ++i) {
     if (retransmittable_frames->frames()[i].type == CONNECTION_CLOSE_FRAME) {
       return true;
     }
   }
   return false;
 }
 
 }  // namespace net