Introducing the WorkerProcessLauncher class implementing the common logic for spawning a worker pro…

remoting/host/wts_session_process_launcher_win.h

 // Copyright (c) 2012 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.
 
 #ifndef REMOTING_HOST_WTS_SESSION_PROCESS_LAUNCHER_WIN_H_
 #define REMOTING_HOST_WTS_SESSION_PROCESS_LAUNCHER_WIN_H_
 
 #include <windows.h>
 
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/process.h"
 #include "base/time.h"
 #include "base/timer.h"
 #include "base/win/scoped_handle.h"
 #include "base/win/object_watcher.h"
 #include "ipc/ipc_channel.h"
 
 #include "remoting/host/wts_console_observer_win.h"
 
 namespace base {
 
-class Thread;
+class MessageLoopProxy;
 
 } // namespace base
 
 namespace IPC {
 
 class ChannelProxy;
 class Message;
 
 } // namespace IPC
 
 namespace remoting {
 
 class SasInjector;
 class WtsConsoleMonitor;
+class WorkerProcessLauncherWin;
 
 class WtsSessionProcessLauncher
-    : public base::win::ObjectWatcher::Delegate,
-      public IPC::Channel::Listener,
+    : public IPC::Channel::Listener,
       public WtsConsoleObserver {
  public:
-  // Constructs a WtsSessionProcessLauncher object. |monitor| and |io_thread|
-  // must outlive this object. |host_binary| is the name of the executable to
-  // be launched in the console session.
-  WtsSessionProcessLauncher(WtsConsoleMonitor* monitor,
-                            const FilePath& host_binary,
-                            base::Thread* io_thread);
+  // Constructs a WtsSessionProcessLauncher object. |monitor| must outlive this
+  // object. |host_binary| is the name of the executable to be launched in
+  // the console session.
+  WtsSessionProcessLauncher(
+      WtsConsoleMonitor* monitor,
+      const FilePath& host_binary,
+      scoped_refptr<base::MessageLoopProxy> ipc_message_loop);
 
   virtual ~WtsSessionProcessLauncher();
 
-  // base::win::ObjectWatcher::Delegate implementation.
-  virtual void OnObjectSignaled(HANDLE object) OVERRIDE;
-
   // IPC::Channel::Listener implementation.
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+  virtual void OnChannelError() OVERRIDE;
 
   // WtsConsoleObserver implementation.
   virtual void OnSessionAttached(uint32 session_id) OVERRIDE;
   virtual void OnSessionDetached() OVERRIDE;
 
  private:
+  // Takes the channel name and returns a channel handle for the server end of
+  // the channel.
+  bool CreateChannelHandle(const std::string& channel_name,
+                           IPC::ChannelHandle* channel_handle_out);
+
+  // Launches a worker process passing the IPC channel name to it.
+  bool LaunchWorker(const std::string& channel_name,
+                    base::Process* process_out);
+
   // Attempts to launch the host process in the current console session.
   // Schedules next launch attempt if creation of the process fails for any
   // reason.
   void LaunchProcess();

[Wez, 2012/03/27 16:45:45]

nit: Re-name this to LaunchWtsSessionProcess() to make its relevance over
LaunchWorker clearer. Replacing the two Callbacks with a single delegate
interface should also help with that.

 
   // Sends the Secure Attention Sequence to the session represented by
   // |session_token_|.
   void OnSendSasToConsole();
 
   // Name of the host executable.
   FilePath host_binary_;
 
+  // Message loop used by the IPC channel.
+  scoped_refptr<base::MessageLoopProxy> ipc_message_loop_;
+
+  // This is a place to store pipe handle until the host process has been

[Wez, 2012/03/27 16:45:45]

nit: "Used to store the IPC pipe handle until the worked process has been
started."?

+  // started.
+  base::win::ScopedHandle ipc_pipe_;
+
   // Time of the last launch attempt.
   base::Time launch_time_;
 
   // Current backoff delay.
   base::TimeDelta launch_backoff_;
 
+  scoped_ptr<WorkerProcessLauncherWin> launcher_;
+
   // Timer used to schedule the next attempt to launch the process.
   base::OneShotTimer<WtsSessionProcessLauncher> timer_;
 
-  // The I/O thread hosts the Chromoting IPC channel and any other code
-  // requiring an I/O message loop.
-  base::Thread* io_thread_;
-
   // This pointer is used to unsubscribe from session attach and detach events.
   WtsConsoleMonitor* monitor_;
 
   // Impersonation token that has the SE_TCB_NAME privilege enabled.
   base::win::ScopedHandle privileged_token_;
 
-  // The handle of the process injected into the console session.
-  base::Process process_;
-
-  // Used to determine when the launched process terminates.
-  base::win::ObjectWatcher process_watcher_;
-
   // The token to be used to launch a process in a different session.
   base::win::ScopedHandle session_token_;
 
-  // Defines the states the process launcher can be in.
-  enum State {
-    StateDetached,
-    StateStarting,
-    StateAttached,
-  };
-
-  // Current state of the process launcher.
-  State state_;
-
-  // The Chromoting IPC channel connecting the service to the per-session
-  // process.
-  scoped_ptr<IPC::ChannelProxy> chromoting_channel_;
-
   scoped_ptr<SasInjector> sas_injector_;
 
   DISALLOW_COPY_AND_ASSIGN(WtsSessionProcessLauncher);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_WTS_SESSION_PROCESS_LAUNCHER_WIN_H_