Add implementations of mojo::{Run,Terminate}[Main]Application() for "chromium".

mojo/application/run_application.cc

+// Copyright 2016 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 "mojo/public/cpp/application/run_application.h"
+
+#include <memory>
+
+#include "base/at_exit.h"
+#include "base/command_line.h"
+#include "base/debug/stack_trace.h"
+#include "base/message_loop/message_loop.h"
+#include "base/threading/thread_local_storage.h"
+#include "build/build_config.h"
+#include "mojo/message_pump/message_pump_mojo.h"
+#include "mojo/public/cpp/application/application_impl_base.h"
+#include "mojo/public/cpp/system/message_pipe.h"
+
+namespace mojo {
+
+namespace {
+
+base::ThreadLocalStorage::StaticSlot g_current_result_holder = TLS_INITIALIZER;
+
+// We store a pointer to a |ResultHolder|, which just stores a |MojoResult|, in
+// TLS so that |TerminateApplication()| can provide the result that
+// |RunApplication()| will return. (The |ResultHolder| is just on
+// |RunApplication()|'s stack.)
+struct ResultHolder {
+#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
+  bool is_set = false;
+#endif
+  // TODO(vtl): The default result should probably be |MOJO_RESULT_UNKNOWN|, but
+  // |ApplicationRunnerChromium| always returned |MOJO_RESULT_OK|.

[vardhan, 2016/05/25 17:59:54]

would anything break if we changed it now?

[viettrungluu, 2016/05/25 18:10:07]

Yes, see CL description.

+  MojoResult result = MOJO_RESULT_OK;
+};
+
+}  // namespace
+
+MojoResult RunMainApplication(MojoHandle application_request_handle,
+                              ApplicationImplBase* application_impl) {
+  base::CommandLine::Init(0, nullptr);
+  base::AtExitManager at_exit;
+
+  g_current_result_holder.Initialize(nullptr);
+
+#if !defined(NDEBUG) && !defined(OS_NACL)
+  base::debug::EnableInProcessStackDumping();
+#endif
+
+  return RunApplication(application_request_handle, application_impl);
+}
+
+MojoResult RunApplication(MojoHandle application_request_handle,
+                          ApplicationImplBase* application_impl) {
+  DCHECK(!g_current_result_holder.Get());
+
+  ResultHolder result_holder;
+  g_current_result_holder.Set(&result_holder);
+
+  std::unique_ptr<base::MessageLoop> loop;
+  // TODO(vtl): Support other types of message loops. (That's why I'm leaving
+  // |loop| as a unique_ptr.)
+  loop.reset(new base::MessageLoop(common::MessagePumpMojo::Create()));
+  application_impl->Bind(InterfaceRequest<Application>(
+      MakeScopedHandle(MessagePipeHandle(application_request_handle))));
+  loop->Run();
+
+  g_current_result_holder.Set(nullptr);
+
+  // TODO(vtl): We'd like to enable the following assertion, but we quit the
+  // current message loop directly in various places.
+  // DCHECK(result_holder.is_set);
+
+  return result_holder.result;
+}
+
+void TerminateMainApplication(MojoResult result) {
+  TerminateApplication(result);
+}
+
+void TerminateApplication(MojoResult result) {
+  DCHECK(base::MessageLoop::current()->is_running());
+  base::MessageLoop::current()->Quit();
+
+  ResultHolder* result_holder =
+      static_cast<ResultHolder*>(g_current_result_holder.Get());
+  DCHECK(result_holder);
+  DCHECK(!result_holder->is_set);
+  result_holder->result = result;
+#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
+  result_holder->is_set = true;
+#endif
+}
+
+}  // namespace mojo