Fix memory corruption from SetMaxPacingRate by inlining PacingSender.

net/quic/core/congestion_control/pacing_sender.cc

 // Copyright (c) 2013 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/core/congestion_control/pacing_sender.h"
 
 #include <string>
 
 #include "net/quic/core/quic_flags.h"
 
 using std::min;
 
 namespace net {
+namespace {
 
-PacingSender::PacingSender(SendAlgorithmInterface* sender,
-                           QuicTime::Delta alarm_granularity,
-                           uint32_t initial_packet_burst)
-    : sender_(sender),
-      alarm_granularity_(alarm_granularity),
-      initial_packet_burst_(initial_packet_burst),
+// The estimated system alarm granularity.
+static const QuicTime::Delta kAlarmGranularity =
+    QuicTime::Delta::FromMilliseconds(1);
+
+// Configured maximum size of the burst coming out of quiescence.  The burst
+// is never larger than the current CWND in packets.
+static const uint32_t kInitialUnpacedBurst = 10;
+
+}  // namespace
+
+PacingSender::PacingSender()
+    : sender_(nullptr),
       max_pacing_rate_(QuicBandwidth::Zero()),
-      burst_tokens_(initial_packet_burst),
+      burst_tokens_(kInitialUnpacedBurst),
       last_delayed_packet_sent_time_(QuicTime::Zero()),
       ideal_next_packet_send_time_(QuicTime::Zero()),
       was_last_send_delayed_(false) {}
 
 PacingSender::~PacingSender() {}
 
-void PacingSender::SetFromConfig(const QuicConfig& config,
-                                 Perspective perspective) {
-  sender_->SetFromConfig(config, perspective);
+void PacingSender::set_sender(SendAlgorithmInterface* sender) {
+  DCHECK(sender != nullptr);
+  sender_ = sender;
 }
 
-void PacingSender::ResumeConnectionState(
-    const CachedNetworkParameters& cached_network_params,
-    bool max_bandwidth_resumption) {
-  sender_->ResumeConnectionState(cached_network_params,
-                                 max_bandwidth_resumption);
-}
-
-void PacingSender::SetNumEmulatedConnections(int num_connections) {
-  sender_->SetNumEmulatedConnections(num_connections);
-}
-
-void PacingSender::SetMaxPacingRate(QuicBandwidth max_pacing_rate) {
-  max_pacing_rate_ = max_pacing_rate;
-}
-
-void PacingSender::OnCongestionEvent(bool rtt_updated,
-                                     QuicByteCount bytes_in_flight,
-                                     const CongestionVector& acked_packets,
-                                     const CongestionVector& lost_packets) {
+void PacingSender::OnCongestionEvent(
+    bool rtt_updated,
+    QuicByteCount bytes_in_flight,
+    const SendAlgorithmInterface::CongestionVector& acked_packets,
+    const SendAlgorithmInterface::CongestionVector& lost_packets) {
+  DCHECK(sender_ != nullptr);
   if (!lost_packets.empty()) {
     // Clear any burst tokens when entering recovery.
     burst_tokens_ = 0;
   }
   sender_->OnCongestionEvent(rtt_updated, bytes_in_flight, acked_packets,
                              lost_packets);
 }
 
 bool PacingSender::OnPacketSent(
     QuicTime sent_time,
     QuicByteCount bytes_in_flight,
     QuicPacketNumber packet_number,
     QuicByteCount bytes,
     HasRetransmittableData has_retransmittable_data) {
+  DCHECK(sender_ != nullptr);
   const bool in_flight =
       sender_->OnPacketSent(sent_time, bytes_in_flight, packet_number, bytes,
                             has_retransmittable_data);
   if (has_retransmittable_data != HAS_RETRANSMITTABLE_DATA) {
     return in_flight;
   }
   // If in recovery, the connection is not coming out of quiescence.
   if (bytes_in_flight == 0 && !sender_->InRecovery()) {
     // Add more burst tokens anytime the connection is leaving quiescence, but
     // limit it to the equivalent of a single bulk write, not exceeding the
     // current CWND in packets.
     burst_tokens_ = min(
-        initial_packet_burst_,
+        kInitialUnpacedBurst,
         static_cast<uint32_t>(sender_->GetCongestionWindow() / kDefaultTCPMSS));
   }
   if (burst_tokens_ > 0) {
     --burst_tokens_;
     was_last_send_delayed_ = false;
     last_delayed_packet_sent_time_ = QuicTime::Zero();
     ideal_next_packet_send_time_ = QuicTime::Zero();
     return in_flight;
   }
   // The next packet should be sent as soon as the current packet has been
@@ skipping 20 matching lines @@
       was_last_send_delayed_ = false;
       last_delayed_packet_sent_time_ = QuicTime::Zero();
     }
   } else {
     ideal_next_packet_send_time_ =
         std::max(ideal_next_packet_send_time_ + delay, sent_time + delay);
   }
   return in_flight;
 }
 
-void PacingSender::OnRetransmissionTimeout(bool packets_retransmitted) {
-  sender_->OnRetransmissionTimeout(packets_retransmitted);
-}
-
-void PacingSender::OnConnectionMigration() {
-  sender_->OnConnectionMigration();
-}
-
 QuicTime::Delta PacingSender::TimeUntilSend(
     QuicTime now,
     QuicByteCount bytes_in_flight) const {
+  DCHECK(sender_ != nullptr);
   QuicTime::Delta time_until_send =
       sender_->TimeUntilSend(now, bytes_in_flight);
   if (burst_tokens_ > 0 || bytes_in_flight == 0) {
     // Don't pace if we have burst tokens available or leaving quiescence.
     return time_until_send;
   }
 
   if (!time_until_send.IsZero()) {
     DCHECK(time_until_send.IsInfinite());
     // The underlying sender prevents sending.
     return time_until_send;
   }
 
   // If the next send time is within the alarm granularity, send immediately.
-  if (ideal_next_packet_send_time_ > now + alarm_granularity_) {
+  if (ideal_next_packet_send_time_ > now + kAlarmGranularity) {
     DVLOG(1) << "Delaying packet: "
              << (ideal_next_packet_send_time_ - now).ToMicroseconds();
     was_last_send_delayed_ = true;
     return ideal_next_packet_send_time_ - now;
   }
 
   DVLOG(1) << "Sending packet now";
   return QuicTime::Delta::Zero();
 }
 
 QuicBandwidth PacingSender::PacingRate(QuicByteCount bytes_in_flight) const {
+  DCHECK(sender_ != nullptr);
   if (!max_pacing_rate_.IsZero()) {
     return QuicBandwidth::FromBitsPerSecond(
         min(max_pacing_rate_.ToBitsPerSecond(),
             sender_->PacingRate(bytes_in_flight).ToBitsPerSecond()));
   }
   return sender_->PacingRate(bytes_in_flight);
 }
 
-QuicBandwidth PacingSender::BandwidthEstimate() const {
-  return sender_->BandwidthEstimate();
-}
-
-QuicTime::Delta PacingSender::RetransmissionDelay() const {
-  return sender_->RetransmissionDelay();
-}
-
-QuicByteCount PacingSender::GetCongestionWindow() const {
-  return sender_->GetCongestionWindow();
-}
-
-bool PacingSender::InSlowStart() const {
-  return sender_->InSlowStart();
-}
-
-bool PacingSender::InRecovery() const {
-  return sender_->InRecovery();
-}
-
-QuicByteCount PacingSender::GetSlowStartThreshold() const {
-  return sender_->GetSlowStartThreshold();
-}
-
-CongestionControlType PacingSender::GetCongestionControlType() const {
-  return sender_->GetCongestionControlType();
-}
-
-std::string PacingSender::GetDebugState() const {
-  return sender_->GetDebugState();
-}
-
-void PacingSender::OnApplicationLimited(QuicByteCount bytes_in_flight) {}
-
 }  // namespace net