Implement Turn/Turn first logic for connection selection.

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.
  */
 
 // P2PTransportChannel wraps up the state management of the connection between
 // two P2P clients.  Clients have candidate ports for connecting, and
 // connections which are combinations of candidates from each end (Alice and
 // Bob each have candidates, one candidate from Alice and one candidate from
 // Bob are used to make a connection, repeat to make many connections).
 //
 // When all of the available connections become invalid (non-writable), we
 // kick off a process of determining more candidates and more connections.
 //
 #ifndef WEBRTC_P2P_BASE_P2PTRANSPORTCHANNEL_H_
 #define WEBRTC_P2P_BASE_P2PTRANSPORTCHANNEL_H_
 
 #include <map>
+#include <set>
 #include <string>
 #include <vector>
 #include "webrtc/p2p/base/candidate.h"
 #include "webrtc/p2p/base/p2ptransport.h"
 #include "webrtc/p2p/base/portallocator.h"
 #include "webrtc/p2p/base/portinterface.h"
 #include "webrtc/p2p/base/transportchannelimpl.h"
 #include "webrtc/base/asyncpacketsocket.h"
 #include "webrtc/base/sigslot.h"
 
@@ skipping 53 matching lines @@
   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;
   // Sets the receiving timeout and gather_continually.
   // This also sets the check_receiving_delay proportionally.
   void SetIceConfig(const IceConfig& config) override;
+  const IceConfig& config() const;
 
   // From TransportChannel:
   int SendPacket(const char* data,
                  size_t len,
                  const rtc::PacketOptions& options,
                  int flags) override;
   int SetOption(rtc::Socket::Option opt, int value) override;
   bool GetOption(rtc::Socket::Option opt, int* value) override;
   int GetError() override { return error_; }
   bool GetStats(std::vector<ConnectionInfo>* stats) override;
@@ skipping 50 matching lines @@
     return false;
   }
 
   // Set DTLS Remote fingerprint. Must be after local identity set.
   bool SetRemoteFingerprint(const std::string& digest_alg,
                             const uint8_t* digest,
                             size_t digest_len) override {
     return false;
   }
 
-  int receiving_timeout() const { return receiving_timeout_; }
+  int receiving_timeout() const { return config_.receiving_timeout_ms; }
   int check_receiving_delay() const { return check_receiving_delay_; }
 
   // Helper method used only in unittest.
   rtc::DiffServCodePoint DefaultDscpValue() const;
 
   // Public for unit tests.
   Connection* FindNextPingableConnection();
+  void MarkConnectionPinged(Connection* conn);
 
   // Public for unit tests.
   const std::vector<Connection*>& connections() const { return connections_; }
 
   // Public for unit tests.
   PortAllocatorSession* allocator_session() {
     return allocator_sessions_.back();
   }
 
   // Public for unit tests.
@@ skipping 58 matching lines @@
   void OnNominated(Connection* conn);
 
   void OnMessage(rtc::Message* pmsg) override;
   void OnSort();
   void OnCheckAndPing();
 
   void PruneConnections();
   Connection* best_nominated_connection() const;
   bool IsBackupConnection(Connection* conn) const;
 
+  Connection* FindConnectionToPing(uint32_t now);
+  Connection* FindOldestConnectionNeedingTriggeredCheck(uint32_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);
+  // Compare the last_ping_sent time and return the one least recently pinged.
+  Connection* LeastRecentlyPinged(Connection* conn1, Connection* conn2);
+
   // Returns the latest remote ICE parameters or nullptr if there are no remote
   // ICE parameters yet.
   IceParameters* remote_ice() {
     return remote_ice_parameters_.empty() ? nullptr
                                           : &remote_ice_parameters_.back();
   }
   // Returns the remote IceParameters and generation that match |ufrag|
   // if found, and returns nullptr otherwise.
   const IceParameters* FindRemoteIceFromUfrag(const std::string& ufrag,
                                               uint32_t* generation);
   // Returns the index of the latest remote ICE parameters, or 0 if no remote
   // ICE parameters have been received.
   uint32_t remote_ice_generation() {
     return remote_ice_parameters_.empty()
                ? 0
                : static_cast<uint32_t>(remote_ice_parameters_.size() - 1);
   }
 
   PortAllocator* allocator_;
   rtc::Thread* worker_thread_;
   bool incoming_only_;
   int error_;
   std::vector<PortAllocatorSession*> allocator_sessions_;
   std::vector<PortInterface *> ports_;
+
+  // |connections_| is a sorted list with the first one always be the
+  // |best_connection_| when it's not nullptr. The combination of
+  // |pinged_connections_| and |unpinged_connections_| has the same
+  // connections as |connections_|. These 2 sets maintain whether a
+  // connection should be pinged next or not.
   std::vector<Connection *> connections_;
+  std::set<Connection*> pinged_connections_;
+  std::set<Connection*> unpinged_connections_;
+
   Connection* best_connection_;
+
   // Connection selected by the controlling agent. This should be used only
   // at controlled side when protocol type is RFC5245.
   Connection* pending_best_connection_;
   std::vector<RemoteCandidate> remote_candidates_;
   bool sort_dirty_;  // indicates whether another sort is needed right now
   bool had_connection_ = false;  // if connections_ has ever been nonempty
   typedef std::map<rtc::Socket::Option, int> OptionMap;
   OptionMap options_;
   std::string ice_ufrag_;
   std::string ice_pwd_;
   std::vector<IceParameters> remote_ice_parameters_;
   IceMode remote_ice_mode_;
   IceRole ice_role_;
   uint64_t tiebreaker_;
   IceGatheringState gathering_state_;
 
   int check_receiving_delay_;
-  int receiving_timeout_;
-  int backup_connection_ping_interval_;
   uint32_t last_ping_sent_ms_ = 0;
-  bool gather_continually_ = false;
   int weak_ping_delay_ = WEAK_PING_DELAY;
   TransportChannelState state_ = TransportChannelState::STATE_INIT;
+  IceConfig config_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(P2PTransportChannel);
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_P2PTRANSPORTCHANNEL_H_