Implements new, more robust design for communicating between SSLConnectJobs.

net/socket/ssl_client_socket_pool.h

Index: net/socket/ssl_client_socket_pool.h
diff --git a/net/socket/ssl_client_socket_pool.h b/net/socket/ssl_client_socket_pool.h
index e03b76ade6ab5946e2d981e7d7802b1cb70d6dba..849b621d5e1069c9993166ecda97c7b34c985917 100644
--- a/net/socket/ssl_client_socket_pool.h
+++ b/net/socket/ssl_client_socket_pool.h
@@ -5,7 +5,9 @@
 #ifndef NET_SOCKET_SSL_CLIENT_SOCKET_POOL_H_
 #define NET_SOCKET_SSL_CLIENT_SOCKET_POOL_H_
 
+#include <map>
 #include <string>
+#include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ -94,23 +96,84 @@ class NET_EXPORT_PRIVATE SSLSocketParams
   DISALLOW_COPY_AND_ASSIGN(SSLSocketParams);
 };
 
+// SSLConnectJobMessenger handles communication between concurrent
+// SSLConnectJobs that share the same SSL session cache key.
+//
+// SSLConnectJobMessengers tell the session cache when a certain
+// connection should be monitored for success or failure, and
+// tell SSLConnectJobs when to pause or resume thier connections.

[Ryan Sleevi, 2014/07/18 22:01:17]

typo: thier -> their

[mshelley, 2014/07/21 23:00:09]

Done.

+class SSLConnectJobMessenger {
+ public:
+  struct SocketAndCallback {
+    SocketAndCallback(SSLClientSocket* ssl_socket,
+                      const base::Closure& job_resumption_callback)
+        : socket(ssl_socket), callback(job_resumption_callback) {}
+
+    SSLClientSocket* socket;
+    base::Closure callback;
+  };
+
+  typedef std::vector<SocketAndCallback> SSLPendingSocketsAndCallbacks;
+
+  // Removes |socket| from |pending_sockets_and_callbacks_| if it is present.

[Ryan Sleevi, 2014/07/18 22:01:17]

Rather than talking strictly about what this does, talk about what the
guarantees are that this affords callers

eg:
// Removes |ssl_socket| from the set of sockets being monitored. This
// guarantees that |job_resumption_callback| will not be called for
// the socket.

(if it actually does; i.e. no PostTask possibilities)

[mshelley, 2014/07/21 23:00:08]

Done.

+  void RemovePendingSocket(SSLClientSocket* ssl_socket);
+
+  // Returns true if |ssl_socket|'s Connect() method should be called.
+  bool CanProceed(SSLClientSocket* ssl_socket);
+
+  // Configures the SSLConnectJobMessenger to begin monitoring |ssl_socket|'s
+  // connection status. After a successful connection, or an error,
+  // the messenger will determine which sockets that have been added
+  // via AddPendingSocket() to allow to proceed.
+  void MonitorConnectionResult(SSLClientSocket* ssl_socket);
+
+  // Adds |socket| to the list of sockets waiting to Connect(). When
+  // the messenger has determined that it's an appropriate time for |socket|
+  // to connect, it will asynchronously invoke |callback|.
+  //
+  // Note: It is an error to call AddPendingSocket() without having first
+  // called MonitorConnectionResult() and configuring a socket that WILL
+  // have Connect() called on it.
+  void AddPendingSocket(SSLClientSocket* socket, const base::Closure& callback);

[Ryan Sleevi, 2014/07/18 22:01:17]

nit: variable naming - you call this ssl_socket for the other methods (119, 122,
128). Should probably do the same here.

[mshelley, 2014/07/21 23:00:09]

Done.

+
+ private:
+  // Processes pending callbacks when a socket successfully completes
+  // its connection.
+  void OnJobSucceeded();
+
+  // Processes pending callbacks when a socket encounters an error
+  // while completing its connection.
+  void OnJobFailed();
+
+  // Runs all callbacks stored in |pending_sockets_and_callbacks_|.
+  void RunAllCallbacks(
+      const SSLPendingSocketsAndCallbacks& pending_socket_and_callbacks);
+
+  SSLPendingSocketsAndCallbacks pending_sockets_and_callbacks_;
+  // Note: this field is a vector to allow for future design changes. Currently,
+  // this vector should only ever have one entry.
+  std::vector<SSLClientSocket*> connecting_sockets_;
+};
+
 // SSLConnectJob handles the SSL handshake after setting up the underlying
 // connection as specified in the params.
 class SSLConnectJob : public ConnectJob {
  public:
-  SSLConnectJob(
-      const std::string& group_name,
-      RequestPriority priority,
-      const scoped_refptr<SSLSocketParams>& params,
-      const base::TimeDelta& timeout_duration,
-      TransportClientSocketPool* transport_pool,
-      SOCKSClientSocketPool* socks_pool,
-      HttpProxyClientSocketPool* http_proxy_pool,
-      ClientSocketFactory* client_socket_factory,
-      HostResolver* host_resolver,
-      const SSLClientSocketContext& context,
-      Delegate* delegate,
-      NetLog* net_log);
+  // Note: the SSLConnectJob does not own |messenger| so it must outlive the
+  // job.
+  SSLConnectJob(const std::string& group_name,
+                RequestPriority priority,
+                const scoped_refptr<SSLSocketParams>& params,
+                const base::TimeDelta& timeout_duration,
+                TransportClientSocketPool* transport_pool,
+                SOCKSClientSocketPool* socks_pool,
+                HttpProxyClientSocketPool* http_proxy_pool,
+                ClientSocketFactory* client_socket_factory,
+                HostResolver* host_resolver,
+                const SSLClientSocketContext& context,
+                SSLConnectJobMessenger* messenger,
+                Delegate* delegate,
+                NetLog* net_log);
   virtual ~SSLConnectJob();
 
   // ConnectJob methods.
@@ -126,6 +189,8 @@ class SSLConnectJob : public ConnectJob {
     STATE_SOCKS_CONNECT_COMPLETE,
     STATE_TUNNEL_CONNECT,
     STATE_TUNNEL_CONNECT_COMPLETE,
+    STATE_CREATE_SSL_SOCKET,
+    STATE_CHECK_FOR_RESUME,
     STATE_SSL_CONNECT,
     STATE_SSL_CONNECT_COMPLETE,
     STATE_NONE,
@@ -142,9 +207,14 @@ class SSLConnectJob : public ConnectJob {
   int DoSOCKSConnectComplete(int result);
   int DoTunnelConnect();
   int DoTunnelConnectComplete(int result);
+  int DoCreateSSLSocket();
+  int DoCheckForResume();
   int DoSSLConnect();
   int DoSSLConnectComplete(int result);
 
+  // Tells a waiting SSLConnectJob to resume its SSL connection.
+  void ResumeSSLConnection();
+
   // Returns the initial state for the state machine based on the
   // |connection_type|.
   static State GetInitialState(SSLSocketParams::ConnectionType connection_type);
@@ -164,12 +234,15 @@ class SSLConnectJob : public ConnectJob {
   const SSLClientSocketContext context_;
 
   State next_state_;
-  CompletionCallback callback_;
+  CompletionCallback io_callback_;
   scoped_ptr<ClientSocketHandle> transport_socket_handle_;
   scoped_ptr<SSLClientSocket> ssl_socket_;
 
+  SSLConnectJobMessenger* messenger_;
   HttpResponseInfo error_response_info_;
 
+  base::WeakPtrFactory<SSLConnectJob> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(SSLConnectJob);
 };
 
@@ -253,6 +326,11 @@ class NET_EXPORT_PRIVATE SSLClientSocketPool
   // HigherLayeredPool implementation.
   virtual bool CloseOneIdleConnection() OVERRIDE;
 
+  // Enables SSLConnectJob waiting if |enable| is true.
+  static NET_EXPORT void set_enable_connect_job_waiting(bool enable);
+
+  static NET_EXPORT bool get_enable_connect_job_waiting();
+
  private:
   typedef ClientSocketPoolBase<SSLSocketParams> PoolBase;
 
@@ -273,7 +351,7 @@ class NET_EXPORT_PRIVATE SSLClientSocketPool
         const SSLClientSocketContext& context,
         NetLog* net_log);
 
-    virtual ~SSLConnectJobFactory() {}
+    virtual ~SSLConnectJobFactory();
 
     // ClientSocketPoolBase::ConnectJobFactory methods.
     virtual scoped_ptr<ConnectJob> NewConnectJob(
@@ -284,6 +362,9 @@ class NET_EXPORT_PRIVATE SSLClientSocketPool
     virtual base::TimeDelta ConnectionTimeout() const OVERRIDE;
 
    private:
+    // Maps SSLConnectJob cache keys to SSLConnectJobMessenger objects.
+    typedef std::map<std::string, SSLConnectJobMessenger*> MessengerMap;
+
     TransportClientSocketPool* const transport_pool_;
     SOCKSClientSocketPool* const socks_pool_;
     HttpProxyClientSocketPool* const http_proxy_pool_;
@@ -292,6 +373,8 @@ class NET_EXPORT_PRIVATE SSLClientSocketPool
     const SSLClientSocketContext context_;
     base::TimeDelta timeout_;
     NetLog* net_log_;
+    // TODO(mshelley) Change this to a non-pointer.
+    scoped_ptr<MessengerMap> messenger_map_;
 
     DISALLOW_COPY_AND_ASSIGN(SSLConnectJobFactory);
   };
@@ -302,6 +385,8 @@ class NET_EXPORT_PRIVATE SSLClientSocketPool
   PoolBase base_;
   const scoped_refptr<SSLConfigService> ssl_config_service_;
 
+  static bool enable_connect_job_waiting_;
+
   DISALLOW_COPY_AND_ASSIGN(SSLClientSocketPool);
 };