Say "noto" goto.

Also, fix DCHECK due to incorrect cleanup when app_library fails to load.

R=ben@chromium.org, darin@chromium.org

Review URL: https://codereview.chromium.org/56553002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@232756 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 81 insertions, 18 deletions

diff --git a/mojo/mojo.gyp b/mojo/mojo.gyp
index 3cf650f..afda2d0 100644
--- a/mojo/mojo.gyp
+++ b/mojo/mojo.gyp
@@ -135,6 +135,7 @@
         '../net/net.gyp:net',
         '../url/url.gyp:url_lib',
         'mojo_system',
+        'mojo_utility',
         'native_viewport',
       ],
       'sources': [
@@ -215,6 +216,17 @@
       ],
     },
     {
+      'target_name': 'mojo_utility',
+      'type': 'static_library',
+      'dependencies': [
+        'mojo_system'
+      ],
+      'sources': [
+        'public/utility/scoped_handle.cc',
+        'public/utility/scoped_handle.h',
+      ],
+    },
+    {
       'target_name': 'sample_app',
       'type': 'shared_library',
       'dependencies': [
diff --git a/mojo/public/utility/scoped_handle.cc b/mojo/public/utility/scoped_handle.cc
new file mode 100644
index 0000000..cba4b8a
--- /dev/null
+++ b/mojo/public/utility/scoped_handle.cc
@@ -0,0 +1,25 @@
+// Copyright 2013 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/utility/scoped_handle.h"
+
+namespace mojo {
+
+ScopedHandle::ScopedHandle(Handle handle) : handle_(handle) {
+}
+
+ScopedHandle::~ScopedHandle() {
+  if (handle_.value == kInvalidHandle.value)
+    return;
+  Close(handle_);
+  Release();
+}
+
+Handle ScopedHandle::Release() {
+  Handle temp = handle_;
+  handle_ = kInvalidHandle;
+  return temp;
+}
+
+}  // namespace mojo
diff --git a/mojo/public/utility/scoped_handle.h b/mojo/public/utility/scoped_handle.h
new file mode 100644
index 0000000..e153baa
--- /dev/null
+++ b/mojo/public/utility/scoped_handle.h
@@ -0,0 +1,27 @@
+// Copyright 2013 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 MOJO_PUBLIC_UTILITY_SCOPED_HANDLE_H_
+#define MOJO_PUBLIC_UTILITY_SCOPED_HANDLE_H_
+
+#include "mojo/public/system/core.h"
+
+namespace mojo {
+
+// Closes handle_ when deleted.
+// This probably wants tons of improvements, but those can be made as needed.
+class ScopedHandle {
+ public:
+  ScopedHandle(Handle handle);
+  ~ScopedHandle();
+  Handle get() const { return handle_; }
+  Handle Release();
+
+ private:
+  Handle handle_;
+};
+
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_SYSTEM_SCOPED_HANDLE_H_
diff --git a/mojo/shell/app_container.cc b/mojo/shell/app_container.cc
index 234f06d..221c871 100644
--- a/mojo/shell/app_container.cc
+++ b/mojo/shell/app_container.cc
@@ -6,12 +6,15 @@
 
 #include "base/bind.h"
 #include "base/callback_forward.h"
+#include "base/callback_helpers.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/native_library.h"
+#include "base/scoped_native_library.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/thread.h"
 #include "mojo/public/system/core.h"
+#include "mojo/public/utility/scoped_handle.h"
 #include "mojo/services/native_viewport/native_viewport_controller.h"
 #include "mojo/shell/context.h"
 
@@ -22,36 +25,32 @@ namespace shell {
 
 void LaunchAppOnThread(
     const base::FilePath& app_path,
-    Handle app_handle) {
-  MojoResult result = MOJO_RESULT_OK;
-  MojoMainFunction main_function = NULL;
-
-  base::NativeLibrary app_library = base::LoadNativeLibrary(app_path, NULL);
-  if (!app_library) {
+    Handle app_handle_raw) {
+  base::ScopedClosureRunner app_deleter(
+      base::Bind(base::IgnoreResult(&base::DeleteFile), app_path, false));
+  ScopedHandle app_handle(app_handle_raw);
+
+  base::ScopedNativeLibrary app_library(
+      base::LoadNativeLibrary(app_path, NULL));
+  if (!app_library.is_valid()) {
     LOG(ERROR) << "Failed to load library: " << app_path.value().c_str();
-    goto completed;
+    return;
   }
 
-  main_function = reinterpret_cast<MojoMainFunction>(
-      base::GetFunctionPointerFromNativeLibrary(app_library, "MojoMain"));
+  MojoMainFunction main_function = reinterpret_cast<MojoMainFunction>(
+      app_library.GetFunctionPointer("MojoMain"));
   if (!main_function) {
     LOG(ERROR) << "Entrypoint MojoMain not found.";
-    goto completed;
+    return;
   }
 
-  result = main_function(app_handle);
+  MojoResult result = main_function(app_handle.get());
   if (result < MOJO_RESULT_OK) {
     LOG(ERROR) << "MojoMain returned an error: " << result;
-    // TODO(*): error handling?
-    goto completed;
+    return;
   }
 
   LOG(INFO) << "MojoMain succeeded: " << result;
-
-completed:
-  base::UnloadNativeLibrary(app_library);
-  base::DeleteFile(app_path, false);
-  Close(app_handle);
 }
 
 AppContainer::AppContainer(Context* context)