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

remoting/host/worker_process_launcher_win.cc

+// 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.
+//
+// This file implements the Windows service controlling Me2Me host processes
+// running within user sessions.
+
+#include "remoting/host/worker_process_launcher.h"
+
+#include <windows.h>
+
+#include "base/win/object_watcher.h"
+
+namespace {
+
+class WorkerProcessLauncherWin : public remoting::WorkerProcessLauncher,
+                                 public base::win::ObjectWatcher::Delegate {
+ public:
+  WorkerProcessLauncherWin(base::MessageLoopProxy* ipc_message_loop);
+  virtual ~WorkerProcessLauncherWin();
+
+  // base::win::ObjectWatcher::Delegate implementation.
+  virtual void OnObjectSignaled(HANDLE object) OVERRIDE;
+
+  // WorkerProcessLauncher
+  virtual bool Start(IPC::Channel::Listener* listener,
+                     const CreateChannelHandleCallback& create_channel_handle,
+                     const LaunchWorkerCallback& launch_worker) OVERRIDE;
+  virtual void Stop() OVERRIDE;
+
+ private:
+  // Used to determine when the launched process terminates.
+  base::win::ObjectWatcher process_watcher_;
+};
+
+WorkerProcessLauncherWin::WorkerProcessLauncherWin(
+    base::MessageLoopProxy* ipc_message_loop)
+    : remoting::WorkerProcessLauncher(ipc_message_loop) {
+}
+
+WorkerProcessLauncherWin::~WorkerProcessLauncherWin() {
+  Stop();
+}
+
+void WorkerProcessLauncherWin::OnObjectSignaled(HANDLE object) {
+  DCHECK(process_watcher_.GetWatchedObject() == NULL);
+  OnChannelError();
+}
+
+bool WorkerProcessLauncherWin::Start(
+    IPC::Channel::Listener* listener,
+    const CreateChannelHandleCallback& create_channel_handle,
+    const LaunchWorkerCallback& launch_worker) {
+  if (WorkerProcessLauncher::Start(listener,
+                                   create_channel_handle,
+                                   launch_worker)) {
+    // Attach an object watcher to the returned process handle so that we get
+    // notified when the process terminates.
+    if (process_watcher_.StartWatching(get_process().handle(), this)) {
+      return true;
+    } else {
+      Stop();
+    }
+  }
+
+  return false;
+}
+
+void WorkerProcessLauncherWin::Stop() {
+  process_watcher_.StopWatching();
+  WorkerProcessLauncher::Stop();
+}
+
+} // namespace
+
+namespace remoting {
+
+// static
+scoped_ptr<WorkerProcessLauncher> WorkerProcessLauncher::Create(
+    base::MessageLoopProxy* ipc_message_loop) {
+  return scoped_ptr<WorkerProcessLauncher>(
+      new WorkerProcessLauncherWin(ipc_message_loop));
+}
+
+} // namespace remoting