Make utility process run in-process when running in single-process mode.

content/browser/utility_process_host_impl.cc

Index: content/browser/utility_process_host_impl.cc
===================================================================
--- content/browser/utility_process_host_impl.cc	(revision 209067)
+++ content/browser/utility_process_host_impl.cc	(working copy)
@@ -7,15 +7,23 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/sequenced_task_runner.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/synchronization/lock.h"
+#include "base/synchronization/waitable_event.h"
 #include "content/browser/browser_child_process_host_impl.h"
+#include "content/browser/renderer_host/render_process_host_impl.h"
+#include "content/child/child_process.h"
 #include "content/common/child_process_host_impl.h"
 #include "content/common/utility_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/utility_process_host_client.h"
 #include "content/public/common/content_switches.h"
+#include "content/public/common/process_type.h"
+#include "content/utility/utility_thread_impl.h"
 #include "ipc/ipc_switches.h"
 #include "ui/base/ui_base_switches.h"
 #include "webkit/plugins/plugin_switches.h"
@@ -45,6 +53,78 @@
 };
 #endif
 
+class UtilityMainThread : public base::Thread,
+                          public base::MessageLoop::DestructionObserver {
+ public:
+  UtilityMainThread(const std::string& channel_id, IPC::Listener* listener)
+      : Thread("Chrome_InProcUtilityThread"),
+        channel_id_(channel_id),
+        listener_(listener),
+        done_event_(false, false),
+        quit_(false) {
+    channel_.reset(new IPC::Channel(
+        channel_id_, IPC::Channel::MODE_SERVER, listener_));
+    CHECK(channel_->Connect());
+  }
+
+  virtual ~UtilityMainThread() {
+    Stop();
+  }
+
+  void WaitForThreadToFlush() {
+    {
+      base::AutoLock auto_lock(quit_lock_);
+      if (quit_)
+        return;
+
+      message_loop()->PostTask(
+          FROM_HERE,
+          base::Bind(&UtilityMainThread::Flush, base::Unretained(this)));
+    }
+    done_event_.Wait();
+  }
+
+  IPC::Channel* channel() const { return channel_.get(); }
+
+ private:
+  // base::Thread implementation:
+  virtual void Init() OVERRIDE {
+    child_process_.reset(new ChildProcess());
+    child_process_->set_main_thread(new UtilityThreadImpl(channel_id_));
+    base::MessageLoop::current()->AddDestructionObserver(this);
+  }
+
+  virtual void CleanUp() OVERRIDE {
+    child_process_.reset();
+
+    // See comment in RendererMainThread.
+    SetThreadWasQuitProperly(true);
+  }
+
+  // base::MessageLoop::DestructionObserver implementation:
+  virtual void WillDestroyCurrentMessageLoop() OVERRIDE {
+    base::AutoLock auto_lock(quit_lock_);
+    quit_ = true;
+    done_event_.Signal();
+  }
+
+  void Flush() {
+    base::RunLoop().RunUntilIdle();
+    done_event_.Signal();
+  }
+
+  std::string channel_id_;
+  scoped_ptr<IPC::Channel> channel_;
+  IPC::Listener* listener_;
+  scoped_ptr<ChildProcess> child_process_;
+  base::WaitableEvent done_event_;
+
+  base::Lock quit_lock_;  // Synchronizes access to quit_.
+  bool quit_;  // Set to true when the thread destruction observer fires.
+
+  DISALLOW_COPY_AND_ASSIGN(UtilityMainThread);
+};
+
 UtilityProcessHost* UtilityProcessHost::Create(
     UtilityProcessHostClient* client,
     base::SequencedTaskRunner* client_task_runner) {
@@ -64,8 +144,8 @@
       child_flags_(ChildProcessHost::CHILD_NORMAL),
 #endif
       use_linux_zygote_(false),
-      started_(false) {
-  process_.reset(new BrowserChildProcessHostImpl(PROCESS_TYPE_UTILITY, this));
+      started_(false),
+      fake_process_data_(PROCESS_TYPE_UTILITY) {
 }
 
 UtilityProcessHostImpl::~UtilityProcessHostImpl() {
@@ -77,6 +157,9 @@
   if (!StartProcess())
     return false;
 
+  if (in_process_thread_.get())
+    return in_process_thread_->channel()->Send(message);
+
   return process_->Send(message);
 }
 
@@ -106,6 +189,9 @@
 }
 
 const ChildProcessData& UtilityProcessHostImpl::GetData() {
+  if (in_process_thread_.get())
+    return fake_process_data_;
+
   return process_->GetData();
 }
 
@@ -124,84 +210,101 @@
 
   if (is_batch_mode_)
     return true;
-  // Name must be set or metrics_service will crash in any test which
-  // launches a UtilityProcessHost.
-  process_->SetName(ASCIIToUTF16("utility process"));
 
-  std::string channel_id = process_->GetHost()->CreateChannel();
-  if (channel_id.empty())
-    return false;
+  if (RenderProcessHost::run_renderer_in_process()) {
+    // See comment in RenderProcessHostImpl::Init() for the background on why we
+    // support single process mode this way.
+    const std::string channel_id =
+        IPC::Channel::GenerateVerifiedChannelID(std::string());
+    in_process_thread_.reset(new UtilityMainThread(channel_id, this));
+    in_process_thread_->Start();
+  } else {
+    // Name must be set or metrics_service will crash in any test which
+    // launches a UtilityProcessHost.
+    process_.reset(new BrowserChildProcessHostImpl(PROCESS_TYPE_UTILITY, this));
+    process_->SetName(ASCIIToUTF16("utility process"));
 
-  const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
-  int child_flags = child_flags_;
+    std::string channel_id = process_->GetHost()->CreateChannel();
+    if (channel_id.empty())
+      return false;
 
+    const CommandLine& browser_command_line = *CommandLine::ForCurrentProcess();
+    int child_flags = child_flags_;
+
 #if defined(OS_POSIX)
-  bool has_cmd_prefix = browser_command_line.HasSwitch(
-      switches::kUtilityCmdPrefix);
+    bool has_cmd_prefix = browser_command_line.HasSwitch(
+        switches::kUtilityCmdPrefix);
 
-  // When running under gdb, forking /proc/self/exe ends up forking the gdb
-  // executable instead of Chromium. It is almost safe to assume that no
-  // updates will happen while a developer is running with
-  // |switches::kUtilityCmdPrefix|. See ChildProcessHost::GetChildPath() for
-  // a similar case with Valgrind.
-  if (has_cmd_prefix)
-    child_flags = ChildProcessHost::CHILD_NORMAL;
+    // When running under gdb, forking /proc/self/exe ends up forking the gdb
+    // executable instead of Chromium. It is almost safe to assume that no
+    // updates will happen while a developer is running with
+    // |switches::kUtilityCmdPrefix|. See ChildProcessHost::GetChildPath() for
+    // a similar case with Valgrind.
+    if (has_cmd_prefix)
+      child_flags = ChildProcessHost::CHILD_NORMAL;
 #endif
 
-  base::FilePath exe_path = ChildProcessHost::GetChildPath(child_flags);
-  if (exe_path.empty()) {
-    NOTREACHED() << "Unable to get utility process binary name.";
-    return false;
-  }
+    base::FilePath exe_path = ChildProcessHost::GetChildPath(child_flags);
+    if (exe_path.empty()) {
+      NOTREACHED() << "Unable to get utility process binary name.";
+      return false;
+    }
 
-  CommandLine* cmd_line = new CommandLine(exe_path);
-  cmd_line->AppendSwitchASCII(switches::kProcessType,
-                              switches::kUtilityProcess);
-  cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id);
-  std::string locale = GetContentClient()->browser()->GetApplicationLocale();
-  cmd_line->AppendSwitchASCII(switches::kLang, locale);
+    CommandLine* cmd_line = new CommandLine(exe_path);
+    cmd_line->AppendSwitchASCII(switches::kProcessType,
+                                switches::kUtilityProcess);
+    cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id);
+    std::string locale = GetContentClient()->browser()->GetApplicationLocale();
+    cmd_line->AppendSwitchASCII(switches::kLang, locale);
 
-  if (no_sandbox_ || browser_command_line.HasSwitch(switches::kNoSandbox))
-    cmd_line->AppendSwitch(switches::kNoSandbox);
+    if (no_sandbox_ || browser_command_line.HasSwitch(switches::kNoSandbox))
+      cmd_line->AppendSwitch(switches::kNoSandbox);
 #if defined(OS_MACOSX)
-  if (browser_command_line.HasSwitch(switches::kEnableSandboxLogging))
-    cmd_line->AppendSwitch(switches::kEnableSandboxLogging);
+    if (browser_command_line.HasSwitch(switches::kEnableSandboxLogging))
+      cmd_line->AppendSwitch(switches::kEnableSandboxLogging);
 #endif
-  if (browser_command_line.HasSwitch(switches::kDebugPluginLoading))
-    cmd_line->AppendSwitch(switches::kDebugPluginLoading);
+    if (browser_command_line.HasSwitch(switches::kDebugPluginLoading))
+      cmd_line->AppendSwitch(switches::kDebugPluginLoading);
 
 #if defined(OS_POSIX)
-  // TODO(port): Sandbox this on Linux.  Also, zygote this to work with
-  // Linux updating.
-  if (has_cmd_prefix) {
-    // launch the utility child process with some prefix (usually "xterm -e gdb
-    // --args").
-    cmd_line->PrependWrapper(browser_command_line.GetSwitchValueNative(
-        switches::kUtilityCmdPrefix));
-  }
+    // TODO(port): Sandbox this on Linux.  Also, zygote this to work with
+    // Linux updating.
+    if (has_cmd_prefix) {
+      // launch the utility child process with some prefix (usually "xterm -e gdb
+      // --args").
+      cmd_line->PrependWrapper(browser_command_line.GetSwitchValueNative(
+          switches::kUtilityCmdPrefix));
+    }
 
-  cmd_line->AppendSwitchPath(switches::kUtilityProcessAllowedDir, exposed_dir_);
+    cmd_line->AppendSwitchPath(switches::kUtilityProcessAllowedDir, exposed_dir_);
 #endif
 
-  bool use_zygote = false;
+    bool use_zygote = false;
 
 #if defined(OS_LINUX)
-  use_zygote = !no_sandbox_ && use_linux_zygote_;
+    use_zygote = !no_sandbox_ && use_linux_zygote_;
 #endif
 
-  process_->Launch(
+    process_->Launch(
 #if defined(OS_WIN)
-      new UtilitySandboxedProcessLauncherDelegate(exposed_dir_),
+        new UtilitySandboxedProcessLauncherDelegate(exposed_dir_),
 #elif defined(OS_POSIX)
-      use_zygote,
-      env_,
+        use_zygote,
+        env_,
 #endif
-      cmd_line);
+        cmd_line);
+  }
 
   return true;
 }
 
 bool UtilityProcessHostImpl::OnMessageReceived(const IPC::Message& message) {
+  if (in_process_thread_.get()) {
+    // When running in single process mode, wait on the thread to flush its
+    // tasks after every message. This is important for unittests so that we
+    // cleanup.
+    in_process_thread_->WaitForThreadToFlush();
+  }
   client_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(base::IgnoreResult(