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

remoting/host/worker_process_launcher.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.
+
+#include "remoting/host/worker_process_launcher.h"
+
+#include <limits>
+
+#include "base/logging.h"
+#include "base/process_util.h"
+#include "base/rand_util.h"
+#include "base/stringprintf.h"
+#include "base/threading/thread.h"
+#include "base/utf_string_conversions.h"
+#include "ipc/ipc_channel_proxy.h"
+#include "ipc/ipc_message.h"
+#include "ipc/ipc_message_macros.h"
+
+namespace remoting {
+
+WorkerProcessLauncherWin::WorkerProcessLauncherWin(
+    scoped_refptr<base::MessageLoopProxy> ipc_message_loop)
+    : ipc_message_loop_(ipc_message_loop),
+      listener_(NULL) {
+}
+
+WorkerProcessLauncherWin::~WorkerProcessLauncherWin() {
+  Stop();
+}
+
+bool WorkerProcessLauncherWin::Start(
+    IPC::Channel::Listener* listener,
+    const CreateChannelHandleCallback& create_channel_handle,
+    const LaunchWorkerCallback& launch_worker) {
+  DCHECK(ipc_channel_.get() == NULL);
+  DCHECK(listener_ == NULL);
+  DCHECK(process_.handle() == NULL);
+  DCHECK(process_watcher_.GetWatchedObject() == NULL);
+
+  std::string channel_name = GenerateRandomChannelId();
+
+  // Create the IPC channel. Details of channel handle creation are offloaded to
+  // the callback.
+  IPC::ChannelHandle channel_handle;
+  if (create_channel_handle.Run(channel_name, &channel_handle)) {
+    ipc_channel_.reset(new IPC::ChannelProxy(channel_handle,
+                                             IPC::Channel::MODE_SERVER,
+                                             this,
+                                             ipc_message_loop_));
+
+    // Launch the process and attach an object watcher to the returned process
+    // handle so that we get notified if the process terminates.
+    if (launch_worker.Run(channel_name, &process_)) {
+      if (process_watcher_.StartWatching(get_process().handle(), this)) {
+        listener_ = listener;
+        return true;
+      }
+
+      process_.Terminate(0);
+      process_.Close();
+    }
+
+    ipc_channel_.reset();
+  }
+
+  return false;
+}
+
+void WorkerProcessLauncherWin::Stop() {
+  ipc_channel_.reset();
+  listener_ = NULL;
+  process_watcher_.StopWatching();
+  process_.Terminate(0);
+  process_.Close();
+}
+
+void WorkerProcessLauncherWin::Send(IPC::Message* message) {
+  ipc_channel_->Send(message);
+}
+
+void WorkerProcessLauncherWin::OnObjectSignaled(HANDLE object) {
+  DCHECK(process_watcher_.GetWatchedObject() == NULL);
+
+  if (listener_) {
+    listener_->OnChannelError();
+    Stop();
+  }
+}
+
+bool WorkerProcessLauncherWin::OnMessageReceived(const IPC::Message& message) {
+  DCHECK(ipc_channel_.get() != NULL);
+  DCHECK(process_.handle() != NULL);
+
+  return listener_->OnMessageReceived(message);
+}
+
+void WorkerProcessLauncherWin::OnChannelConnected(int32 peer_pid) {
+  DCHECK(ipc_channel_.get() != NULL);
+  DCHECK(process_.handle() != NULL);
+
+  listener_->OnChannelConnected(peer_pid);
+}
+
+void WorkerProcessLauncherWin::OnChannelError() {
+  DCHECK(ipc_channel_.get() != NULL);
+
+  listener_->OnChannelError();
+  Stop();
+}
+
+// N.B. Stolen from src/content/common/child_process_host_impl.cc
+std::string WorkerProcessLauncherWin::GenerateRandomChannelId() {
+  return base::StringPrintf("%d.%p.%d",
+                            base::GetCurrentProcId(), this,

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

Do we really want to include the in-memory address of this object in the channel
Id?

+                            base::RandInt(0, std::numeric_limits<int>::max()));
+}
+
+base::Process& WorkerProcessLauncherWin::get_process() {

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

nit: Prefer to keep methods defined in the order they appear in the header where
possible.

+  return process_;
+}
+
+} // namespace remoting