relnote: Avoid redundant recvmmsg when the previous recvmmsg returned

net/tools/quic/quic_packet_reader.h

 // Copyright 2015 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.
 
 // A class to read incoming QUIC packets from the UDP socket.
 
 #ifndef NET_TOOLS_QUIC_QUIC_PACKET_READER_H_
 #define NET_TOOLS_QUIC_QUIC_PACKET_READER_H_
 
 #include <netinet/in.h>
@@ skipping 19 matching lines @@
 class ProcessPacketInterface;
 class QuicDispatcher;
 
 class QuicPacketReader {
  public:
   QuicPacketReader();
 
   virtual ~QuicPacketReader();
 
   // Reads a number of packets from the given fd, and then passes them off to
-  // the PacketProcessInterface.  Returns true if at least 1 packet is read,
-  // false otherwise.
+  // the PacketProcessInterface.  Returns true if there may be additional
+  // packets available on the socket.
   // Populates |packets_dropped| if it is non-null and the socket is configured
   // to track dropped packets and some packets are read.
   virtual bool ReadAndDispatchPackets(int fd,
                                       int port,
                                       ProcessPacketInterface* processor,
                                       QuicPacketCount* packets_dropped);
 
   // Same as ReadAndDispatchPackets, only does one packet at a time.
   static bool ReadAndDispatchSinglePacket(int fd,
                                           int port,
@@ skipping 17 matching lines @@
   // call on the packets.
   struct sockaddr_storage raw_address_[kNumPacketsPerReadMmsgCall];
 
   DISALLOW_COPY_AND_ASSIGN(QuicPacketReader);
 };
 
 }  // namespace tools
 }  // namespace net
 
 #endif  // NET_TOOLS_QUIC_QUIC_PACKET_READER_H_