Remove ports that are not used by any channel after timeout

webrtc/p2p/base/port.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 104 matching lines @@
 };
 
 typedef std::set<rtc::SocketAddress> ServerAddresses;
 
 // Represents a local communication mechanism that can be used to create
 // connections to similar mechanisms of the other client.  Subclasses of this
 // one add support for specific mechanisms like local UDP ports.
 class Port : public PortInterface, public rtc::MessageHandler,
              public sigslot::has_slots<> {
  public:
+  enum class State { INIT, READY, PRUNED };

[pthatcher1, 2016/07/28 19:35:05]

This could use a description of states.  Such as:

This needs a better description.  Perhaps something "A pruned port or a port in
the pruned state will be destroyed as soon as no candidate pairs are using it
for a period of 30 seconds".  A live-until-pruned port will not be destroyed
until it is pruned.  Pruning a port moves it to PRUNED.  No other state
transitions are allowed.

By the way, I think "ALIVE_UNTIL_PRUNED" is a better name than "ready".

[honghaiz3, 2016/07/28 22:51:44]

Done.

   Port(rtc::Thread* thread,
        const std::string& type,
        rtc::PacketSocketFactory* factory,
        rtc::Network* network,
        const rtc::IPAddress& ip,
        const std::string& username_fragment,
        const std::string& password);
   Port(rtc::Thread* thread,
        const std::string& type,
        rtc::PacketSocketFactory* factory,
@@ skipping 11 matching lines @@
   // Methods to set/get ICE role and tiebreaker values.
   IceRole GetIceRole() const { return ice_role_; }
   void SetIceRole(IceRole role) { ice_role_ = role; }
 
   void SetIceTiebreaker(uint64_t tiebreaker) { tiebreaker_ = tiebreaker; }
   uint64_t IceTiebreaker() const { return tiebreaker_; }
 
   virtual bool SharedSocket() const { return shared_socket_; }
   void ResetSharedSocket() { shared_socket_ = false; }
 
+  // Called when a port is ready to use.
+  void BecomeReady();

[pthatcher1, 2016/07/28 19:35:05]

I think a better name would be "KeepAliveUntilPruned", which keeps it alive
until it's pruned.

[honghaiz3, 2016/07/28 22:51:44]

Done.

+  // Called when a port is pruned.

[pthatcher1, 2016/07/28 19:35:05]

A better comment would be "Allows the port to be destroyed once no connections
are using it."

[honghaiz3, 2016/07/28 22:52:28]

Done.

+  void Prune();
+
   // The thread on which this port performs its I/O.
   rtc::Thread* thread() { return thread_; }
 
   // The factory used to create the sockets of this port.
   rtc::PacketSocketFactory* socket_factory() const { return factory_; }
   void set_socket_factory(rtc::PacketSocketFactory* factory) {
     factory_ = factory;
   }
 
   // For debugging purposes.
@@ skipping 124 matching lines @@
   // Called when the socket is currently able to send.
   void OnReadyToSend();
 
   // Called when the Connection discovers a local peer reflexive candidate.
   // Returns the index of the new local candidate.
   size_t AddPrflxCandidate(const Candidate& local);
 
   int16_t network_cost() const { return network_cost_; }
 
  protected:
-  enum {
-    MSG_DEAD = 0,
-    MSG_FIRST_AVAILABLE
-  };
+  enum { MSG_CHECK_DEAD = 0, MSG_FIRST_AVAILABLE };

[pthatcher1, 2016/07/28 19:35:05]

MSG_MAYBE_DESTORY might be a better name than MSG_CHECK_DEAD.

[honghaiz3, 2016/07/28 22:51:44]

Using MSG_DESTROY_IF_DEAD.

 
   virtual void UpdateNetworkCost();
 
   void set_type(const std::string& type) { type_ = type; }
 
   void AddAddress(const rtc::SocketAddress& address,
                   const rtc::SocketAddress& base_address,
                   const rtc::SocketAddress& related_address,
                   const std::string& protocol,
                   const std::string& relay_protocol,
@@ skipping 36 matching lines @@
   }
 
   // Extra work to be done in subclasses when a connection is destroyed.
   virtual void HandleConnectionDestroyed(Connection* conn) {}
 
  private:
   void Construct();
   // Called when one of our connections deletes itself.
   void OnConnectionDestroyed(Connection* conn);
 
-  // Whether this port is dead, and hence, should be destroyed on the controlled
-  // side.
-  bool dead() const {
-    return ice_role_ == ICEROLE_CONTROLLED && connections_.empty();
-  }
+  // Whether this port is dead, and hence, should be destroyed.
+  bool dead() const;
 
   void OnNetworkTypeChanged(const rtc::Network* network);
 
   rtc::Thread* thread_;
   rtc::PacketSocketFactory* factory_;
   std::string type_;
   bool send_retransmit_count_attribute_;
   rtc::Network* network_;
   rtc::IPAddress ip_;
   uint16_t min_port_;
@@ skipping 19 matching lines @@
   uint64_t tiebreaker_;
   bool shared_socket_;
   // Information to use when going through a proxy.
   std::string user_agent_;
   rtc::ProxyInfo proxy_;
 
   // A virtual cost perceived by the user, usually based on the network type
   // (WiFi. vs. Cellular). It takes precedence over the priority when
   // comparing two connections.
   uint16_t network_cost_;
+  State state_ = State::INIT;
 
   friend class Connection;
 };
 
 // Represents a communication link between a port on the local client and a
 // port on the remote client.
 class Connection : public CandidatePairInterface,
                    public rtc::MessageHandler,
                    public sigslot::has_slots<> {
  public:
@@ skipping 271 matching lines @@
            const rtc::PacketOptions& options) override;
   int GetError() override { return error_; }
 
  private:
   int error_ = 0;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_PORT_H_