Change QuicConnection's ScopedPacketBundler to use SEND_QUEUED_ACK instead of NO_ACK, to ensure a q…

net/quic/quic_connection.h

 // 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.
 //
 // The entity that handles framing writes for a Quic client or server.
 // Each QuicSession will have a connection associated with it.
 //
 // On the server side, the Dispatcher handles the raw reads, and hands off
 // packets via ProcessUdpPacket for framing and processing.
 //
@@ skipping 278 matching lines @@
   virtual QuicBufferAllocator* GetBufferAllocator() = 0;
 };
 
 class NET_EXPORT_PRIVATE QuicConnection
     : public QuicFramerVisitorInterface,
       public QuicBlockedWriterInterface,
       public QuicPacketGenerator::DelegateInterface,
       public QuicSentPacketManager::NetworkChangeVisitor {
  public:
   enum AckBundling {
-    NO_ACK = 0,
-    SEND_ACK = 1,
-    BUNDLE_PENDING_ACK = 2,
+    // Send an ack if it's already queued in the connection.
+    SEND_ACK_IF_QUEUED,
+    // Always send an ack.
+    SEND_ACK,
+    // Bundle an ack with outgoing data.
+    SEND_ACK_IF_PENDING,
   };
 
   enum AckMode { TCP_ACKING, ACK_DECIMATION, ACK_DECIMATION_WITH_REORDERING };
 
   // Constructs a new QuicConnection for |connection_id| and |address| using
   // |writer| to write packets. |owns_writer| specifies whether the connection
   // takes ownership of |writer|. |helper| must outlive this connection.
   QuicConnection(QuicConnectionId connection_id,
                  IPEndPoint address,
                  QuicConnectionHelperInterface* helper,
@@ skipping 294 matching lines @@
   class NET_EXPORT_PRIVATE ScopedPacketBundler {
    public:
     // In addition to all outgoing frames being bundled when the
     // bundler is in scope, setting |include_ack| to true ensures that
     // an ACK frame is opportunistically bundled with the first
     // outgoing packet.
     ScopedPacketBundler(QuicConnection* connection, AckBundling send_ack);
     ~ScopedPacketBundler();
 
    private:
+    bool ShouldSendAck(AckBundling ack_mode) const;
+
     QuicConnection* connection_;
     bool already_in_batch_mode_;
   };
 
   // Delays setting the retransmission alarm until the scope is exited.
   // When nested, only the outermost scheduler will set the alarm, and inner
   // ones have no effect.
   class NET_EXPORT_PRIVATE ScopedRetransmissionScheduler {
    public:
     explicit ScopedRetransmissionScheduler(QuicConnection* connection);
@@ skipping 24 matching lines @@
 
   // Return the name of the cipher of the primary decrypter of the framer.
   const char* cipher_name() const { return framer_.decrypter()->cipher_name(); }
   // Return the id of the cipher of the primary decrypter of the framer.
   uint32_t cipher_id() const { return framer_.decrypter()->cipher_id(); }
 
   std::vector<QuicEncryptedPacket*>* termination_packets() {
     return termination_packets_.get();
   }
 
+  bool ack_queued() const { return ack_queued_; }
+
   bool ack_frame_updated() const;
 
   QuicConnectionHelperInterface* helper() { return helper_; }
 
   base::StringPiece GetCurrentPacket();
 
  protected:
   // Send a packet to the peer, and takes ownership of the packet if the packet
   // cannot be written immediately.
   virtual void SendOrQueuePacket(SerializedPacket* packet);
@@ skipping 170 matching lines @@
   IPEndPoint peer_address_;
 
   // Used to store latest peer IP address for IP address migration.
   IPAddress migrating_peer_ip_;
   // Used to store latest peer port to possibly migrate to later.
   uint16_t migrating_peer_port_;
 
   // True if the last packet has gotten far enough in the framer to be
   // decrypted.
   bool last_packet_decrypted_;
-  QuicByteCount last_size_;   // Size of the last received packet.
+  QuicByteCount last_size_;  // Size of the last received packet.
   // TODO(rch): remove this when b/27221014 is fixed.
   const char* current_packet_data_;  // UDP payload of packet currently being
                                      // parsed or nullptr.
   EncryptionLevel last_decrypted_packet_level_;
   QuicPacketHeader last_header_;
   QuicStopWaitingFrame last_stop_waiting_frame_;
   bool should_last_packet_instigate_acks_;
 
   // Track some peer state so we can do less bookkeeping
   // Largest sequence sent by the peer which had an ack frame (latest ack info).
@@ skipping 177 matching lines @@
 
   // If true, multipath is enabled for this connection.
   bool multipath_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicConnection);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_CONNECTION_H_