Only create the backup ConnectJob when it is needed.

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 210 matching lines @@
     return ClientSocketPool::kMaxConnectRetryIntervalMs;
   }
 
   // ConnectJob::Delegate methods:
   virtual void OnConnectJobComplete(int result, ConnectJob* job);
 
   // NetworkChangeNotifier::Observer methods:
   virtual void OnIPAddressChanged();
 
   int NumConnectJobsInGroup(const std::string& group_name) const {
-    return group_map_.find(group_name)->second.jobs.size();
+    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.
   void CleanupIdleSockets(bool force);
 
   base::TimeDelta ConnectionTimeout() const {
     return connect_job_factory_->ConnectionTimeout();
   }
 
@@ skipping 19 matching lines @@
     // socket for a new request.
     bool ShouldCleanup(base::TimeTicks now, base::TimeDelta timeout) const;
   };
 
   typedef std::deque<const Request*> RequestQueue;
   typedef std::map<const ClientSocketHandle*, const Request*> RequestMap;
 
   // A Group is allocated per group_name when there are idle sockets or pending
   // requests.  Otherwise, the Group object is removed from the map.
   // |active_socket_count| tracks the number of sockets held by clients.
-  struct Group {
-    Group()
-        : active_socket_count(0),
-          backup_job(NULL),
-          backup_task(NULL) {
-    }
-
-    ~Group() {
-      CleanupBackupJob();
-    }
+  class Group {
+   public:
+    Group();
+    ~Group();
 
     bool IsEmpty() const {
-      return active_socket_count == 0 && idle_sockets.empty() && jobs.empty() &&
-          pending_requests.empty();
+      return active_socket_count_ == 0 && idle_sockets_.empty() &&
+          jobs_.empty() && pending_requests_.empty();
     }
 
     bool HasAvailableSocketSlot(int max_sockets_per_group) const {
-      return active_socket_count + static_cast<int>(jobs.size()) <
+      return active_socket_count_ + static_cast<int>(jobs_.size()) <
           max_sockets_per_group;
     }
 
     bool IsStalled(int max_sockets_per_group) const {
       return HasAvailableSocketSlot(max_sockets_per_group) &&
-          pending_requests.size() > jobs.size();
+          pending_requests_.size() > jobs_.size();
     }
 
     RequestPriority TopPendingPriority() const {
-      return pending_requests.front()->priority();
+      return pending_requests_.front()->priority();
     }
 
+    bool HasBackupJob() const { return !method_factory_.empty(); }
+
     void CleanupBackupJob() {
-      if (backup_job) {
-        delete backup_job;
-        backup_job = NULL;
-      }
-      if (backup_task) {
-        backup_task->Cancel();
-        backup_task = NULL;
-      }
+      method_factory_.RevokeAll();
     }
 
-    std::deque<IdleSocket> idle_sockets;
-    std::set<const ConnectJob*> jobs;
-    RequestQueue pending_requests;
-    int active_socket_count;  // number of active sockets used by clients
-    // A backup job in case the connect for this group takes too long.
-    ConnectJob* backup_job;
-    CancelableTask* backup_task;
+    // Set a timer to create a backup socket if it takes too long to create one.
+    void StartBackupSocketTimer(const std::string& group_name,
+                                ClientSocketPoolBaseHelper* pool);
+
+    // Called when the backup socket timer fires.
+    void OnBackupSocketTimerFired(
+        std::string group_name,
+        ClientSocketPoolBaseHelper* pool);
+
+    void AddJob(const ConnectJob* job) { jobs_.insert(job); }
+    void RemoveJob(const ConnectJob* job) { jobs_.erase(job); }
+    void RemoveAllJobs();
+
+    void IncrementActiveSocketCount() { active_socket_count_++; }
+    void DecrementActiveSocketCount() { active_socket_count_--; }
+
+    const std::set<const ConnectJob*>& jobs() const { return jobs_; }
+    const std::deque<IdleSocket>& idle_sockets() const { return idle_sockets_; }
+    const RequestQueue& pending_requests() const { return pending_requests_; }
+    int active_socket_count() const { return active_socket_count_; }
+    RequestQueue* mutable_pending_requests() { return &pending_requests_; }
+    std::deque<IdleSocket>* mutable_idle_sockets() { return &idle_sockets_; }
+
+   private:
+    std::deque<IdleSocket> idle_sockets_;
+    std::set<const ConnectJob*> jobs_;
+    RequestQueue pending_requests_;
+    int active_socket_count_;  // number of active sockets used by clients
+    // A factory to pin the backup_job tasks.
+    ScopedRunnableMethodFactory<Group> method_factory_;
   };
 
-  typedef std::map<std::string, Group> GroupMap;
+  typedef std::map<std::string, Group*> GroupMap;
 
   typedef std::set<const ConnectJob*> ConnectJobSet;
 
   struct CallbackResultPair {
     CallbackResultPair() : callback(NULL), result(OK) {}
     CallbackResultPair(CompletionCallback* callback_in, int result_in)
         : callback(callback_in), result(result_in) {}
 
     CompletionCallback* callback;
     int result;
   };
 
   typedef std::map<const ClientSocketHandle*, CallbackResultPair>
       PendingCallbackMap;
 
   ~ClientSocketPoolBaseHelper();
 
   static void InsertRequestIntoQueue(const Request* r,
                                      RequestQueue* pending_requests);
   static const Request* RemoveRequestFromQueue(RequestQueue::iterator it,
                                                RequestQueue* pending_requests);
 
+  Group* GetOrCreateGroup(const std::string& group_name);
+  void RemoveGroup(const std::string& group_name);
+  void RemoveGroup(GroupMap::iterator it);
+
   // Called when the number of idle sockets changes.
   void IncrementIdleCount();
   void DecrementIdleCount();
 
   // Scans the group map for groups which have an available socket slot and
   // at least one pending request. Returns true if any groups are stalled, and
   // if so, fills |group| and |group_name| with data of the stalled group
   // having highest priority.
   bool FindTopStalledGroup(Group** group, std::string* group_name);
 
@@ skipping 33 matching lines @@
   bool ReachedMaxSocketsLimit() const;
 
   // This is the internal implementation of RequestSocket().  It differs in that
   // it does not handle logging into NetLog of the queueing status of
   // |request|.
   int RequestSocketInternal(const std::string& group_name,
                             const Request* request);
 
   // Assigns an idle socket for the group to the request.
   // Returns |true| if an idle socket is available, false otherwise.
-  bool AssignIdleSocketToGroup(Group* group, const Request* request);
+  bool AssignIdleSocketToGroup(const Request* request, Group* group);
 
   static void LogBoundConnectJobToRequest(
       const NetLog::Source& connect_job_source, const Request* request);
 
-  // Set a timer to create a backup socket if it takes too long to create one.
-  void StartBackupSocketTimer(const std::string& group_name);
-
-  // Called when the backup socket timer fires.
-  void OnBackupSocketTimerFired(const std::string& group_name);
-
   // Closes one idle socket.  Picks the first one encountered.
   // TODO(willchan): Consider a better algorithm for doing this.  Perhaps we
   // should keep an ordered list of idle sockets, and close them in order.
   // Requires maintaining more state.  It's not clear if it's worth it since
   // I'm not sure if we hit this situation often.
   void CloseOneIdleSocket();
 
   // Checks if there are stalled socket groups that should be notified
   // for possible wakeup.
   void CheckForStalledSocketGroups();
@@ skipping 38 matching lines @@
 
   // The time to wait until closing idle sockets.
   const base::TimeDelta unused_idle_socket_timeout_;
   const base::TimeDelta used_idle_socket_timeout_;
 
   const scoped_ptr<ConnectJobFactory> connect_job_factory_;
 
   // 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_;
 
   // Some parts of this class need to know if the destructor is running.
   bool in_destructor_;
 };
 
 }  // namespace internal
@@ skipping 160 matching lines @@
   // ClientSocketPoolBase<T> reference to drop to zero.  While we're deep
   // in cleanup code, we'll often hold a reference to |self|.
   scoped_refptr<internal::ClientSocketPoolBaseHelper> helper_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientSocketPoolBase);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_CLIENT_SOCKET_POOL_BASE_H_