Control the amount of time to leave an unused socket idle before closing it.

net/socket/client_socket_pool_base.h

 // Copyright (c) 2006-2008 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 148 matching lines @@
         const Request& request,
         ConnectJob::Delegate* delegate,
         LoadLog* load_log) const = 0;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(ConnectJobFactory);
   };
 
   ClientSocketPoolBaseHelper(int max_sockets,
                              int max_sockets_per_group,
+                             base::TimeDelta unused_idle_socket_timeout,
+                             base::TimeDelta used_idle_socket_timeout,
                              ConnectJobFactory* connect_job_factory);
 
   ~ClientSocketPoolBaseHelper();
 
   // See ClientSocketPool::RequestSocket for documentation on this function.
   // Note that |request| must be heap allocated.  If ERR_IO_PENDING is returned,
   // then ClientSocketPoolBaseHelper takes ownership of |request|.
   int RequestSocket(const std::string& group_name, const Request* request);
 
   // See ClientSocketPool::CancelRequest for documentation on this function.
@@ skipping 31 matching lines @@
   // afterward and receive the socket from the job).
   static void EnableLateBindingOfSockets(bool enabled);
 
   // 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.
+  void CleanupIdleSockets(bool force);
+
  private:
   // Entry for a persistent socket which became idle at time |start_time|.
   struct IdleSocket {
     IdleSocket() : socket(NULL), used(false) {}
     ClientSocket* socket;
     base::TimeTicks start_time;
     bool used;  // Indicates whether or not the socket has been used yet.
 
     // An idle socket should be removed if it can't be reused, or has been idle
     // for too long. |now| is the current time value (TimeTicks::Now()).
+    // |timeout| is the length of time to wait before timing out an idle socket.
     //
     // An idle socket can't be reused if it is disconnected or has received
     // data unexpectedly (hence no longer idle).  The unread data would be
     // mistaken for the beginning of the next response if we were to reuse the
     // socket for a new request.
-    bool ShouldCleanup(base::TimeTicks now) const;
+    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.
   struct Group {
     Group() : active_socket_count(0) {}
 
@@ skipping 21 matching lines @@
   typedef std::map<std::string, Group> GroupMap;
 
   typedef std::map<const ClientSocketHandle*, ConnectJob*> ConnectJobMap;
   typedef std::set<const ConnectJob*> ConnectJobSet;
 
   static void InsertRequestIntoQueue(const Request* r,
                                      RequestQueue* pending_requests);
   static const Request* RemoveRequestFromQueue(RequestQueue::iterator it,
                                                RequestQueue* pending_requests);
 
-  // Closes all idle sockets if |force| is true.  Else, only closes idle
-  // sockets that timed out or can't be reused.
-  void CleanupIdleSockets(bool force);
-
   // 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);
 
   // 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
@@ skipping 61 matching lines @@
 
   // Number of connected sockets we handed out across all groups.
   int handed_out_socket_count_;
 
   // The maximum total number of sockets. See ReachedMaxSocketsLimit.
   const int max_sockets_;
 
   // The maximum number of sockets kept per group.
   const int max_sockets_per_group_;
 
+  // The time to wait until closing idle sockets.
+  const base::TimeDelta unused_idle_socket_timeout_;
+  const base::TimeDelta used_idle_socket_timeout_;
+
   // Until the maximum number of sockets limit is reached, a group can only
   // have pending requests if it exceeds the "max sockets per group" limit.
   //
   // This means when a socket is released, the only pending requests that can
   // be started next belong to the same group.
   //
   // However once the |max_sockets_| limit is reached, this stops being true:
   // groups can now have pending requests without having first reached the
   // |max_sockets_per_group_| limit. So choosing the next request involves
   // selecting the highest priority request across *all* groups.
   //
   // Since reaching the maximum number of sockets is an edge case, we make note
   // of when it happens, and thus avoid doing the slower "scan all groups"
   // in the common case.
   bool may_have_stalled_group_;
 
   const scoped_ptr<ConnectJobFactory> connect_job_factory_;
 
   // Controls whether or not we use late binding of sockets.
   static bool g_late_binding;
 
 };
 
 }  // 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.
+static const int kUsedIdleSocketTimeout = 300;  // 5 minutes
+
 template <typename SocketParams>
 class ClientSocketPoolBase {
  public:
   class Request : public internal::ClientSocketPoolBaseHelper::Request {
    public:
     Request(ClientSocketHandle* handle,
             CompletionCallback* callback,
             int priority,
             const SocketParams& params,
             LoadLog* load_log)
@@ skipping 15 matching lines @@
     virtual ConnectJob* NewConnectJob(
         const std::string& group_name,
         const Request& request,
         ConnectJob::Delegate* delegate,
         LoadLog* load_log) const = 0;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(ConnectJobFactory);
   };
 
+  // |max_sockets| is the maximum number of sockets to be maintained by this
+  // ClientSocketPool.  |max_sockets_per_group| specifies the maximum number of
+  // sockets a "group" can have.  |unused_idle_socket_timeout| specifies how
+  // long to leave an unused idle socket open before closing it.
+  // |used_idle_socket_timeout| specifies how long to leave a previously used
+  // idle socket open before closing it.
   ClientSocketPoolBase(int max_sockets,
                        int max_sockets_per_group,
+                       base::TimeDelta unused_idle_socket_timeout,
+                       base::TimeDelta used_idle_socket_timeout,
                        ConnectJobFactory* connect_job_factory)
       : helper_(new internal::ClientSocketPoolBaseHelper(
           max_sockets, max_sockets_per_group,
+          unused_idle_socket_timeout, used_idle_socket_timeout,
           new ConnectJobFactoryAdaptor(connect_job_factory))) {}
 
   ~ClientSocketPoolBase() {}
 
   // These member functions simply forward to ClientSocketPoolBaseHelper.
 
   // RequestSocket bundles up the parameters into a Request and then forwards to
   // ClientSocketPoolBaseHelper::RequestSocket().  Note that the memory
   // ownership is transferred in the asynchronous (ERR_IO_PENDING) case.
   int RequestSocket(const std::string& group_name,
@@ skipping 41 matching lines @@
 
   // For testing.
   bool may_have_stalled_group() const {
     return helper_->may_have_stalled_group();
   }
 
   int NumConnectJobsInGroup(const std::string& group_name) const {
     return helper_->NumConnectJobsInGroup(group_name);
   }
 
+  void CleanupIdleSockets(bool force) {
+    return helper_->CleanupIdleSockets(force);
+  }
+
  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 31 matching lines @@
 // decoupled from socket connection jobs.  A socket request may initiate a
 // socket connection job, but there is no guarantee that that socket
 // connection will service the request (for example, a released socket may
 // service the request sooner, or a higher priority request may come in
 // afterward and receive the socket from the job).
 void EnableLateBindingOfSockets(bool enabled);
 
 }  // namespace net
 
 #endif  // NET_SOCKET_CLIENT_SOCKET_POOL_BASE_H_