Close idle connections / SPDY sessions when needed.

net/socket/client_socket_pool_base.h

Index: net/socket/client_socket_pool_base.h
diff --git a/net/socket/client_socket_pool_base.h b/net/socket/client_socket_pool_base.h
index 5000f36a45c0e72b950d3579b5e68507ff08fb46..8e33cd20035cf65673b9b271cccaea2f9a335cee 100644
--- a/net/socket/client_socket_pool_base.h
+++ b/net/socket/client_socket_pool_base.h
@@ -28,6 +28,7 @@
 #include <map>
 #include <set>
 #include <string>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
@@ -239,6 +240,11 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
 
   virtual ~ClientSocketPoolBaseHelper();
 
+  // Adds/Removes layered pools. It is expected in the destructor that no
+  // layered pools remain.
+  void AddLayeredPool(LayeredPool* pool);
+  void RemoveLayeredPool(LayeredPool* pool);
+
   // See ClientSocketPool::RequestSocket for documentation on this function.
   // ClientSocketPoolBaseHelper takes ownership of |request|, which must be
   // heap allocated.
@@ -261,6 +267,9 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
   // See ClientSocketPool::Flush for documentation on this function.
   void Flush();
 
+  // See ClientSocketPool::IsStalled for documentation on this function.
+  bool IsStalled() const;
+
   // See ClientSocketPool::CloseIdleSockets for documentation on this function.
   void CloseIdleSockets();
 
@@ -305,6 +314,13 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
   // sockets that timed out or can't be reused.  Made public for testing.
   void CleanupIdleSockets(bool force);
 
+  // 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.

[mmenke, 2011/11/28 17:47:14]

Random comment:  Since we hit this situation often enough with proxies for this
CL to be worth it, we may well hit this situation enough in proxy situations to
be smarter about which socket we close.  Would say it's low priority,
regardless, though.  And yea, I know you just copied the comment.

[willchan no longer on Chromium, 2011/11/29 23:14:52]

You're probably right. I'll file a bug.

+  bool CloseOneIdleSocket();
+
   // See ClientSocketPool::GetInfoAsValue for documentation on this function.
   base::DictionaryValue* GetInfoAsValue(const std::string& name,
                                         const std::string& type) const;
@@ -321,6 +337,9 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
   // ConnectJob::Delegate methods:
   virtual void OnConnectJobComplete(int result, ConnectJob* job) OVERRIDE;
 
+  // Checks layered pools to see if they can close an idle connection.
+  bool CloseOneIdleConnectionInLayeredPool();

[mmenke, 2011/11/28 17:47:14]

nit:  No need to reorder everything to be consistent, but this function and
CloseOneIdleSocket are declared right next ro each other in
ClientSocketPoolBase, so it seems logical to have them right next to each other
here as well, and the same for their bodies in the cc file.

[willchan no longer on Chromium, 2011/11/29 23:14:52]

Done.

+
   // NetworkChangeNotifier::IPAddressObserver methods:
   virtual void OnIPAddressChanged() OVERRIDE;
 
@@ -457,7 +476,7 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
   // 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);
+  bool FindTopStalledGroup(Group** group, std::string* group_name) const;
 
   // Called when timer_ fires.  This method scans the idle sockets removing
   // sockets that timed out or can't be reused.
@@ -509,13 +528,6 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
   static void LogBoundConnectJobToRequest(
       const NetLog::Source& connect_job_source, const Request* request);
 
-  // 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();
-
   // Same as CloseOneIdleSocket() except it won't close an idle socket in
   // |group|.  If |group| is NULL, it is ignored.  Returns true if it closed a
   // socket.
@@ -580,6 +592,8 @@ class NET_EXPORT_PRIVATE ClientSocketPoolBaseHelper
   // make sure that they are discarded rather than reused.
   int pool_generation_number_;
 
+  std::set<LayeredPool*> higher_layer_pools_;
+
   ScopedRunnableMethodFactory<ClientSocketPoolBaseHelper> method_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientSocketPoolBaseHelper);
@@ -646,6 +660,13 @@ class ClientSocketPoolBase {
   virtual ~ClientSocketPoolBase() {}
 
   // These member functions simply forward to ClientSocketPoolBaseHelper.
+  void AddLayeredPool(LayeredPool* pool) {
+    helper_.AddLayeredPool(pool);
+  }
+
+  void RemoveLayeredPool(LayeredPool* pool) {
+    helper_.RemoveLayeredPool(pool);
+  }
 
   // RequestSocket bundles up the parameters into a Request and then forwards to
   // ClientSocketPoolBaseHelper::RequestSocket().
@@ -690,6 +711,10 @@ class ClientSocketPoolBase {
     return helper_.ReleaseSocket(group_name, socket, id);
   }
 
+  void Flush() { helper_.Flush(); }
+
+  bool IsStalled() const { return helper_.IsStalled(); }
+
   void CloseIdleSockets() { return helper_.CloseIdleSockets(); }
 
   int idle_socket_count() const { return helper_.idle_socket_count(); }
@@ -738,7 +763,11 @@ class ClientSocketPoolBase {
 
   void EnableConnectBackupJobs() { helper_.EnableConnectBackupJobs(); }
 
-  void Flush() { helper_.Flush(); }
+  bool CloseOneIdleSocket() { return helper_.CloseOneIdleSocket(); }
+
+  bool CloseOneIdleConnectionInLayeredPool() {
+    return helper_.CloseOneIdleConnectionInLayeredPool();
+  }
 
  private:
   // This adaptor class exists to bridge the