Deciding best connection to schedule requests on based on cwnd and idle time

net/socket/client_socket_pool_base.h

 // Copyright (c) 2011 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 149 matching lines @@
       public NetworkChangeNotifier::IPAddressObserver {
  public:
   typedef uint32 Flags;
 
   // Used to specify specific behavior for the ClientSocketPool.
   enum Flag {
     NORMAL = 0,  // Normal behavior.
     NO_IDLE_SOCKETS = 0x1,  // Do not return an idle socket. Create a new one.
   };
 
+  enum ClientSocketReusePolicy {
+    USE_WARMEST_SOCKET = 0,
+    USE_WARM_SOCKET = 1,
+    USE_LAST_ACCESSED_SOCKET = 2,
+  };
+
   class NET_TEST Request {
    public:
     Request(ClientSocketHandle* handle,
             CompletionCallback* callback,
             RequestPriority priority,
             bool ignore_limits,
             Flags flags,
             const BoundNetLog& net_log);
 
     virtual ~Request();
@@ skipping 103 matching lines @@
   DictionaryValue* GetInfoAsValue(const std::string& name,
                                   const std::string& type) const;
 
   base::TimeDelta ConnectionTimeout() const {
     return connect_job_factory_->ConnectionTimeout();
   }
 
   static bool connect_backup_jobs_enabled();
   static bool set_connect_backup_jobs_enabled(bool enabled);
 
+  // Sets the client socket reuse policy (using warmest socket vs. last accessed
+  // socket).
+  static double SetSocketReusePolicy(int policy);

[Mike Belshe, 2011/06/12 22:10:35]

Instead of an int, you could use a ClientSocketReusePolicy.

[Gagan, 2011/06/13 03:52:47]

was doing that initially, but ran into problems in browser_main.cc where i had
to convert the command line value to enum. So used int instead.

Have added a comment saying that policy should be a valid enum.

+
   void EnableConnectBackupJobs();
 
   // ConnectJob::Delegate methods:
   virtual void OnConnectJobComplete(int result, ConnectJob* job);
 
   // NetworkChangeNotifier::IPAddressObserver methods:
   virtual void OnIPAddressChanged();
 
  private:
   friend class base::RefCounted<ClientSocketPoolBaseHelper>;
@@ skipping 433 matching lines @@
           group_name, *casted_request, delegate);
     }
 
     virtual base::TimeDelta ConnectionTimeout() const {
       return connect_job_factory_->ConnectionTimeout();
     }
 
     const scoped_ptr<ConnectJobFactory> connect_job_factory_;
   };
 
+  void ApplySocketReuseGroup(int warmest_socket_trial_group,
+                             const int* socket_policy);
   // Histograms for the pool
   ClientSocketPoolHistograms* const histograms_;
   internal::ClientSocketPoolBaseHelper helper_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientSocketPoolBase);
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_CLIENT_SOCKET_POOL_BASE_H_