Start ICE connectivity checks as soon as the first pair is pingable.

webrtc/p2p/base/p2ptransportchannel.h

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 75 matching lines @@
   // From TransportChannelImpl:
   TransportChannelState GetState() const override;
   void SetIceRole(IceRole role) override;
   IceRole GetIceRole() const override { return ice_role_; }
   void SetIceTiebreaker(uint64_t tiebreaker) override;
   void SetIceCredentials(const std::string& ice_ufrag,
                          const std::string& ice_pwd) override;
   void SetRemoteIceCredentials(const std::string& ice_ufrag,
                                const std::string& ice_pwd) override;
   void SetRemoteIceMode(IceMode mode) override;
-  void Connect() override;
   void MaybeStartGathering() override;
   IceGatheringState gathering_state() const override {
     return gathering_state_;
   }
   void AddRemoteCandidate(const Candidate& candidate) override;
   void RemoveRemoteCandidate(const Candidate& candidate) override;
   // Sets the parameters in IceConfig. We do not set them blindly. Instead, we
   // only update the parameter if it is considered set in |config|. For example,
   // a negative value of receiving_timeout will be considered "not set" and we
   // will not use it to update the respective parameter in |config_|.
@@ skipping 101 matching lines @@
  private:
   rtc::Thread* thread() { return worker_thread_; }
   bool IsGettingPorts() { return allocator_session()->IsGettingPorts(); }
 
   // A transport channel is weak if the current best connection is either
   // not receiving or not writable, or if there is no best connection at all.
   bool weak() const;
   // Returns true if it's possible to send packets on this channel.
   bool ReadyToSend() const;
   void UpdateConnectionStates();
-  void RequestSort();
+  void RequestSortAndStateUpdate();
+  // Start pinging if we haven't already started, and we now have a connection
+  // that's pingable.
+  void MaybeStartPinging();
 
   // The methods below return a positive value if a is preferable to b,
   // a negative value if b is preferable, and 0 if they're equally preferable.
   int CompareConnectionStates(const cricket::Connection* a,
                               const cricket::Connection* b) const;
   int CompareConnectionCandidates(const cricket::Connection* a,
                                   const cricket::Connection* b) const;
   // Compares two connections based on the connection states
   // (writable/receiving/connected), nomination states, last data received time,
   // and static preferences. Does not include latency. Used by both sorting
   // and ShouldSwitchSelectedConnection().
   // Returns a positive value if |a| is better than |b|.
   int CompareConnections(const cricket::Connection* a,
                          const cricket::Connection* b) const;
 
   bool PresumedWritable(const cricket::Connection* conn) const;
 
-  void SortConnections();
+  bool ShouldSwitchSelectedConnection(const cricket::Connection* selected,
+                                      const cricket::Connection* conn) const;
+  void SortConnectionsAndUpdateState();
   void SwitchSelectedConnection(Connection* conn);
   void UpdateState();
   void HandleAllTimedOut();
   void MaybeStopPortAllocatorSessions();
   TransportChannelState ComputeState() const;
 
   Connection* GetBestConnectionOnNetwork(rtc::Network* network) const;
   bool CreateConnections(const Candidate& remote_candidate,
                          PortInterface* origin_port);
   bool CreateConnection(PortInterface* port,
                         const Candidate& remote_candidate,
                         PortInterface* origin_port);
   bool FindConnection(cricket::Connection* connection) const;
 
   uint32_t GetRemoteCandidateGeneration(const Candidate& candidate);
   bool IsDuplicateRemoteCandidate(const Candidate& candidate);
   void RememberRemoteCandidate(const Candidate& remote_candidate,
                                PortInterface* origin_port);
-  bool IsPingable(Connection* conn, int64_t now);
+  bool IsPingable(const Connection* conn, int64_t now) const;
   bool IsSelectedConnectionPingable(int64_t now);
-  int CalculateActiveWritablePingInterval(Connection* conn, int64_t now);
+  int CalculateActiveWritablePingInterval(const Connection* conn,
+                                          int64_t now) const;
   void PingConnection(Connection* conn);
   void AddAllocatorSession(std::unique_ptr<PortAllocatorSession> session);
   void AddConnection(Connection* connection);
 
   void OnPortReady(PortAllocatorSession *session, PortInterface* port);
   void OnCandidatesReady(PortAllocatorSession *session,
                          const std::vector<Candidate>& candidates);
   void OnCandidatesAllocationDone(PortAllocatorSession* session);
   void OnUnknownAddress(PortInterface* port,
                         const rtc::SocketAddress& addr,
                         ProtocolType proto,
                         IceMessage* stun_msg,
                         const std::string& remote_username,
                         bool port_muxed);
   void OnPortDestroyed(PortInterface* port);
   void OnPortNetworkInactive(PortInterface* port);
   void OnRoleConflict(PortInterface* port);
 
   void OnConnectionStateChange(Connection* connection);
   void OnReadPacket(Connection *connection, const char *data, size_t len,
                     const rtc::PacketTime& packet_time);
   void OnSentPacket(const rtc::SentPacket& sent_packet);
   void OnReadyToSend(Connection* connection);
   void OnConnectionDestroyed(Connection *connection);
 
   void OnNominated(Connection* conn);
 
   void OnMessage(rtc::Message* pmsg) override;
-  void OnSort();
   void OnCheckAndPing();
 
   // Returns true if the new_connection should be selected for transmission.
   bool ShouldSwitchSelectedConnection(Connection* new_connection) const;
 
   void PruneConnections();
-  bool IsBackupConnection(Connection* conn) const;
+  bool IsBackupConnection(const Connection* conn) const;
 
   Connection* FindConnectionToPing(int64_t now);
   Connection* FindOldestConnectionNeedingTriggeredCheck(int64_t now);
   // Between |conn1| and |conn2|, this function returns the one which should
   // be pinged first.
   Connection* SelectMostPingableConnection(Connection* conn1,
                                            Connection* conn2);
   // Select the connection which is Relay/Relay. If both of them are,
   // UDP relay protocol takes precedence.
   Connection* MostLikelyToWork(Connection* conn1, Connection* conn2);
@@ skipping 55 matching lines @@
   IceRole ice_role_;
   uint64_t tiebreaker_;
   IceGatheringState gathering_state_;
 
   int check_receiving_interval_;
   int64_t last_ping_sent_ms_ = 0;
   int weak_ping_interval_ = WEAK_PING_INTERVAL;
   TransportChannelState state_ = TransportChannelState::STATE_INIT;
   IceConfig config_;
   int last_sent_packet_id_ = -1;  // -1 indicates no packet was sent before.
+  bool started_pinging_ = false;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(P2PTransportChannel);
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_P2PTRANSPORTCHANNEL_H_