Cancel pending retransmissions which are greater than the largest newly acked packet when using the…

net/quic/quic_sent_packet_manager.h

 // Copyright 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.
 
 #ifndef NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_
 #define NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 140 matching lines @@
   // they don't get retransmitted.
   void NeuterUnencryptedPackets();
 
   // Returns true if the unacked packet |packet_number| has retransmittable
   // frames.  This will only return false if the packet has been acked, if a
   // previous transmission of this packet was ACK'd, or if this packet has been
   // retransmitted as with different packet number.
   bool HasRetransmittableFrames(QuicPacketNumber packet_number) const;
 
   // Returns true if there are pending retransmissions.
+  // Not const because retransmissions may be cancelled before returning.
   bool HasPendingRetransmissions() const;
 
   // Retrieves the next pending retransmission.  You must ensure that
   // there are pending retransmissions prior to calling this function.
   PendingRetransmission NextPendingRetransmission();
 
   bool HasUnackedPackets() const;
 
   // Returns the smallest packet number of a serialized packet which has not
   // been acked by the peer.
@@ skipping 256 matching lines @@
   // Number of pending transmissions of TLP, RTO, or crypto packets.
   size_t pending_timer_transmission_count_;
   // Maximum number of tail loss probes to send before firing an RTO.
   size_t max_tail_loss_probes_;
   // If true, send the TLP at 0.5 RTT.
   bool enable_half_rtt_tail_loss_probe_;
   bool using_pacing_;
   // If true, use the new RTO with loss based CWND reduction instead of the send
   // algorithms's OnRetransmissionTimeout to reduce the congestion window.
   bool use_new_rto_;
+  // If true, cancel pending retransmissions if they're larger than
+  // largest_newly_acked.
+  bool undo_pending_retransmits_;
 
   // Vectors packets acked and lost as a result of the last congestion event.
   SendAlgorithmInterface::CongestionVector packets_acked_;
   SendAlgorithmInterface::CongestionVector packets_lost_;
   // Largest newly acknowledged packet.
   QuicPacketNumber largest_newly_acked_;
 
   // Set to true after the crypto handshake has successfully completed. After
   // this is true we no longer use HANDSHAKE_MODE, and further frames sent on
   // the crypto stream (i.e. SCUP messages) are treated like normal
   // retransmittable frames.
   bool handshake_confirmed_;
 
   // Records bandwidth from server to client in normal operation, over periods
   // of time with no loss events.
   QuicSustainedBandwidthRecorder sustained_bandwidth_recorder_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicSentPacketManager);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_