Do not attempt to reuse active sockets after a socket pool flush (usually a network change).

net/socket/client_socket_pool_base.h

 // Copyright (c) 2010 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 ClientSocketPoolBase is used to restrict the number of sockets open at
 // a time.  It also maintains a list of idle persistent sockets for reuse.
 // Subclasses of ClientSocketPool should compose ClientSocketPoolBase to handle
 // the core logic of (1) restricting the number of active (connected or
 // connecting) sockets per "group" (generally speaking, the hostname), (2)
 // maintaining a per-group list of idle, persistent sockets for reuse, and (3)
@@ skipping 170 matching lines @@
   // ClientSocketPoolBaseHelper takes ownership of |request|, which must be
   // heap allocated.
   int RequestSocket(const std::string& group_name, const Request* request);
 
   // See ClientSocketPool::CancelRequest for documentation on this function.
   void CancelRequest(const std::string& group_name,
                      const ClientSocketHandle* handle);
 
   // See ClientSocketPool::ReleaseSocket for documentation on this function.
   void ReleaseSocket(const std::string& group_name,
-                     ClientSocket* socket);
+                     ClientSocket* socket,
+                     int id);
 
+  // See ClientSocketPool::Flush for documentation on this function.
+  void Flush();
+  
   // See ClientSocketPool::CloseIdleSockets for documentation on this function.
   void CloseIdleSockets();
 
   // See ClientSocketPool::IdleSocketCount() for documentation on this function.
   int idle_socket_count() const {
     return idle_socket_count_;
   }
 
   // See ClientSocketPool::IdleSocketCountInGroup() for documentation on this
   // function.
   int IdleSocketCountInGroup(const std::string& group_name) const;
 
   // See ClientSocketPool::GetLoadState() for documentation on this function.
   LoadState GetLoadState(const std::string& group_name,
                          const ClientSocketHandle* handle) const;
 
   int ConnectRetryIntervalMs() const {
     // TODO(mbelshe): Make this tuned dynamically based on measured RTT.
     //                For now, just use the max retry interval.
     return ClientSocketPool::kMaxConnectRetryIntervalMs;
   }
 
   // ConnectJob::Delegate methods:
   virtual void OnConnectJobComplete(int result, ConnectJob* job);
 
   // NetworkChangeNotifier::Observer methods:
-  virtual void OnIPAddressChanged();
+  virtual void OnIPAddressChanged() { Flush(); }
 
   // For testing.
   bool may_have_stalled_group() const { return may_have_stalled_group_; }
 
   int NumConnectJobsInGroup(const std::string& group_name) const {
     return group_map_.find(group_name)->second.jobs.size();
   }
 
   // Closes all idle sockets if |force| is true.  Else, only closes idle
   // sockets that timed out or can't be reused.  Made public for testing.
@@ skipping 98 matching lines @@
   static void InsertRequestIntoQueue(const Request* r,
                                      RequestQueue* pending_requests);
   static const Request* RemoveRequestFromQueue(RequestQueue::iterator it,
                                                RequestQueue* pending_requests);
 
   // Called when the number of idle sockets changes.
   void IncrementIdleCount();
   void DecrementIdleCount();
 
   // Called via PostTask by ReleaseSocket.
-  void DoReleaseSocket(const std::string& group_name, ClientSocket* socket);
+  void DoReleaseSocket(
+      const std::string& group_name, ClientSocket* socket, int id);
 
   // Scans the group map for groups which have an available socket slot and
   // at least one pending request. Returns number of groups found, and if found
   // at least one, fills |group| and |group_name| with data of the stalled group
   // having highest priority.
   int FindTopStalledGroup(Group** group, std::string* group_name);
 
   // Called when timer_ fires.  This method scans the idle sockets removing
   // sockets that timed out or can't be reused.
   void OnCleanupTimerFired() {
@@ skipping 95 matching lines @@
 
   const scoped_ptr<ConnectJobFactory> connect_job_factory_;
 
   NetworkChangeNotifier* const network_change_notifier_;
 
   // TODO(vandebo) Remove when backup jobs move to TCPClientSocketPool
   bool backup_jobs_enabled_;
 
   // A factory to pin the backup_job tasks.
   ScopedRunnableMethodFactory<ClientSocketPoolBaseHelper> method_factory_;
+
+  // A unique id for the pool.  It gets incremented every time we Flush() the
+  // pool.  This is so that when sockets get released back to the pool, we can
+  // make sure that they are discarded rather than reused.
+  int pool_generation_number_;
 };
 
 }  // namespace internal
 
 // The maximum duration, in seconds, to keep unused idle persistent sockets
 // alive.
 // TODO(willchan): Change this timeout after getting histogram data on how
 // long it should be.
 static const int kUnusedIdleSocketTimeout = 10;
 // The maximum duration, in seconds, to keep used idle persistent sockets alive.
@@ skipping 71 matching lines @@
                     const BoundNetLog& net_log) {
     Request* request = new Request(handle, callback, priority, params, net_log);
     return helper_->RequestSocket(group_name, request);
   }
 
   void CancelRequest(const std::string& group_name,
                      const ClientSocketHandle* handle) {
     return helper_->CancelRequest(group_name, handle);
   }
 
-  void ReleaseSocket(const std::string& group_name, ClientSocket* socket) {
-    return helper_->ReleaseSocket(group_name, socket);
+  void ReleaseSocket(const std::string& group_name, ClientSocket* socket, int id) {
+    return helper_->ReleaseSocket(group_name, socket, id);
   }
 
   void CloseIdleSockets() { return helper_->CloseIdleSockets(); }
 
   int idle_socket_count() const { return helper_->idle_socket_count(); }
 
   int IdleSocketCountInGroup(const std::string& group_name) const {
     return helper_->IdleSocketCountInGroup(group_name);
   }
 
@@ skipping 22 matching lines @@
   base::TimeDelta ConnectionTimeout() const {
     return helper_->ConnectionTimeout();
   }
 
   scoped_refptr<ClientSocketPoolHistograms> histograms() const {
     return histograms_;
   }
 
   void enable_backup_jobs() { helper_->enable_backup_jobs(); }
 
+  void Flush() { helper_->Flush(); }
+
  private:
   // This adaptor class exists to bridge the
   // internal::ClientSocketPoolBaseHelper::ConnectJobFactory and
   // ClientSocketPoolBase::ConnectJobFactory types, allowing clients to use the
   // typesafe ClientSocketPoolBase::ConnectJobFactory, rather than having to
   // static_cast themselves.
   class ConnectJobFactoryAdaptor
       : public internal::ClientSocketPoolBaseHelper::ConnectJobFactory {
    public:
     typedef typename ClientSocketPoolBase<SocketParams>::ConnectJobFactory
@@ skipping 29 matching lines @@
   // the posting of the task and the execution, then we'll hit the DCHECK that
   // |ClientSocketPoolBaseHelper::group_map_| is empty.
   scoped_refptr<internal::ClientSocketPoolBaseHelper> helper_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientSocketPoolBase);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_CLIENT_SOCKET_POOL_BASE_H_