[Chromoting] Moving common logic responsible for launching child processes to WorkerProcessLauncher…

remoting/host/win/wts_session_process_launcher.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_WIN_WTS_SESSION_PROCESS_LAUNCHER_H_
 #define REMOTING_HOST_WIN_WTS_SESSION_PROCESS_LAUNCHER_H_
 
 #include <windows.h>
 
 #include "base/basictypes.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/base/stoppable.h"
+#include "remoting/host/win/worker_process_launcher.h"
 #include "remoting/host/win/wts_console_observer.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 } // namespace base
 
 namespace IPC {
 class ChannelProxy;
 class Message;
 } // namespace IPC
 
 namespace remoting {
 
 class SasInjector;
 class WtsConsoleMonitor;
 
 class WtsSessionProcessLauncher
     : public Stoppable,
-      public base::win::ObjectWatcher::Delegate,
-      public IPC::Listener,
+      public WorkerProcessLauncher::Delegate,
       public WtsConsoleObserver {
  public:
   // Constructs a WtsSessionProcessLauncher object. All interaction with
   // |monitor| should happen on |main_message_loop|. |ipc_message_loop| has
   // to be an I/O message loop.

[Wez, 2012/08/08 20:13:41]

Clarify the semantics of "stopped_callback", which it seems will be called every
time a worker process instance is stopped, e.g. due to a session switch.

[alexeypa (please no reviews), 2012/08/08 21:49:58]

Done.

   WtsSessionProcessLauncher(
       const base::Closure& stopped_callback,
       WtsConsoleMonitor* monitor,
       scoped_refptr<base::SingleThreadTaskRunner> main_message_loop,
       scoped_refptr<base::SingleThreadTaskRunner> ipc_message_loop);
 
   virtual ~WtsSessionProcessLauncher();
 
-  // base::win::ObjectWatcher::Delegate implementation.
-  virtual void OnObjectSignaled(HANDLE object) OVERRIDE;
-
-  // IPC::Listener implementation.
+  // WorkerProcessLauncher::Delegate implementation.
+  virtual bool DoLaunchProcess(const std::string& channel_name,
+                               base::win::ScopedHandle* wait_out) OVERRIDE;
+  virtual void DoKillProcess(DWORD exit_code) OVERRIDE;
+  virtual void OnChannelConnected(base::win::ScopedHandle peer) OVERRIDE;
   virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
   // WtsConsoleObserver implementation.
   virtual void OnSessionAttached(uint32 session_id) OVERRIDE;
   virtual void OnSessionDetached() OVERRIDE;
 
  protected:
   // Stoppable implementation.
   virtual void DoStop() OVERRIDE;
 
  private:
   // 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();
 
+  // Called when the launcher reports the process to be stopped.
+  void OnLauncherStopped();
+
   // Sends the Secure Attention Sequence to the session represented by
   // |session_token_|.
   void OnSendSasToConsole();
 
+  // Tracks whether the object is attached to the console session.

[Wez, 2012/08/08 20:13:41]

nit: "True if this object is currently attached to the console session."

[alexeypa (please no reviews), 2012/08/08 21:49:58]

Done.

+  bool attached_;

[Wez, 2012/08/08 20:13:41]

nit: Consider storing the ID of the session to which we're attached, or -1 if
not attached, rather than just this flag?

[alexeypa (please no reviews), 2012/08/08 21:49:58]

It will not be used so there is no point is storing it. The code change is
trivial once such need arise.

+
   // Time of the last launch attempt.
   base::Time launch_time_;
 
   // Current backoff delay.
   base::TimeDelta launch_backoff_;
 
   // Timer used to schedule the next attempt to launch the process.
   base::OneShotTimer<WtsSessionProcessLauncher> timer_;
 
   // The main service message loop.
   scoped_refptr<base::SingleThreadTaskRunner> main_message_loop_;
 
   // Message loop used by the IPC channel.
   scoped_refptr<base::SingleThreadTaskRunner> ipc_message_loop_;
 
   // This pointer is used to unsubscribe from session attach and detach events.
   WtsConsoleMonitor* monitor_;
 
-  // The handle of the process injected into the console session.
-  base::Process process_;
+  scoped_ptr<WorkerProcessLauncher> launcher_;

[Wez, 2012/08/08 20:13:41]

nit: worker_process_launcher_

[alexeypa (please no reviews), 2012/08/08 21:49:58]

No, I think it is OK to keep it |launcher_| just like we keep |launch_time_|,
|launch_backoff_| and other member not prefixed.

 
-  // Used to determine when the launched process terminates.
-  base::win::ObjectWatcher process_watcher_;
+  base::win::ScopedHandle worker_process_;
 
   // 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_WIN_WTS_SESSION_PROCESS_LAUNCHER_H_