Move microtask queue into tonic

Moving the microtask queue into tonic solves three problems:

1) Removes three levels of indirection when invoking microtask
callbacks.
2) Removes the sky/engine/dom directory entirely.
3) Removes the last client of the (inefficient) DartValue class.

sky/engine/bindings/dart_runtime_hooks.cc

@@ -15,7 +15,6 @@
 #include "dart/runtime/bin/embedded_dart_io.h"
 #include "dart/runtime/include/dart_api.h"
 #include "dart/runtime/include/dart_tools_api.h"
-#include "sky/engine/core/dom/Microtask.h"
 #include "sky/engine/core/script/dom_dart_state.h"
 #include "sky/engine/tonic/dart_api_scope.h"
 #include "sky/engine/tonic/dart_converter.h"
@@ -23,9 +22,9 @@
 #include "sky/engine/tonic/dart_invoke.h"
 #include "sky/engine/tonic/dart_isolate_scope.h"
 #include "sky/engine/tonic/dart_library_natives.h"
+#include "sky/engine/tonic/dart_microtask_queue.h"
 #include "sky/engine/tonic/dart_state.h"
 #include "sky/engine/tonic/dart_timer_heap.h"
-#include "sky/engine/tonic/dart_value.h"
 #include "sky/engine/wtf/text/WTFString.h"
 
 #if defined(OS_ANDROID)
@@ -163,23 +162,11 @@ void Logger_PrintString(Dart_NativeArguments args) {
   }
 }
 
-static void ExecuteMicrotask(base::WeakPtr<DartState> dart_state,
-                             RefPtr<DartValue> callback) {
-  if (!dart_state)
-    return;
-  DartIsolateScope scope(dart_state->isolate());
-  DartApiScope api_scope;
-  DartInvokeAppClosure(callback->dart_value(), 0, nullptr);
-}
-
 void ScheduleMicrotask(Dart_NativeArguments args) {
   Dart_Handle closure = Dart_GetNativeArgument(args, 0);
   if (LogIfError(closure) || !Dart_IsClosure(closure))
     return;
-  DartState* dart_state = DartState::Current();
-  CHECK(dart_state);
-  Microtask::enqueueMicrotask(base::Bind(&ExecuteMicrotask,
-    dart_state->GetWeakPtr(), DartValue::Create(dart_state, closure)));
+  DartMicrotaskQueue::ScheduleMicrotask(closure);
 }
 
 void GetBaseURLString(Dart_NativeArguments args) {

sky/engine/core/core.gni

@@ -11,8 +11,6 @@ sky_core_files = [
   "compositing/Scene.h",
   "compositing/SceneBuilder.cpp",
   "compositing/SceneBuilder.h",
-  "dom/Microtask.cpp",
-  "dom/Microtask.h",
   "editing/CompositionUnderline.h",
   "editing/CompositionUnderlineRangeFilter.cpp",
   "editing/CompositionUnderlineRangeFilter.h",

sky/engine/core/dom/Microtask.cpp

-/*
- * Copyright (C) 2013 Google Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer
- *    in the documentation and/or other materials provided with the
- *    distribution.
- * 3. Neither the name of Google Inc. nor the names of its contributors
- *    may be used to endorse or promote products derived from this
- *    software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "sky/engine/core/dom/Microtask.h"
-
-#include "base/bind.h"
-#include "base/trace_event/trace_event.h"
-#include "sky/engine/public/platform/WebThread.h"
-#include "sky/engine/wtf/OwnPtr.h"
-#include "sky/engine/wtf/Vector.h"
-
-namespace blink {
-
-namespace {
-
-class Task : public WebThread::Task {
-public:
-    explicit Task(const base::Closure& closure)
-        : m_closure(closure)
-    {
-    }
-
-    virtual void run() override
-    {
-        m_closure.Run();
-    }
-
-private:
-    base::Closure m_closure;
-};
-
-}
-
-// TODO(dart): Integrate this microtask queue with darts.
-typedef Vector<OwnPtr<WebThread::Task> > MicrotaskQueue;
-static MicrotaskQueue& microtaskQueue()
-{
-    DEFINE_STATIC_LOCAL(OwnPtr<MicrotaskQueue>, queue, (adoptPtr(new MicrotaskQueue())));
-    return *queue;
-}
-
-void Microtask::performCheckpoint()
-{
-    MicrotaskQueue& queue = microtaskQueue();
-    while(!queue.isEmpty()) {
-        TRACE_EVENT0("flutter", "Microtask::performCheckpoint");
-
-        MicrotaskQueue local;
-        swap(queue, local);
-        for (const auto& task : local)
-            task->run();
-    }
-}
-
-void Microtask::enqueueMicrotask(PassOwnPtr<WebThread::Task> callback)
-{
-    microtaskQueue().append(callback);
-}
-
-void Microtask::enqueueMicrotask(const base::Closure& callback)
-{
-    enqueueMicrotask(adoptPtr(new Task(callback)));
-}
-
-} // namespace blink

sky/engine/core/dom/Microtask.h

-/*
- * Copyright (C) 2013 Google Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer
- *    in the documentation and/or other materials provided with the
- *    distribution.
- * 3. Neither the name of Google Inc. nor the names of its contributors
- *    may be used to endorse or promote products derived from this
- *    software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#ifndef SKY_ENGINE_CORE_DOM_MICROTASK_H_
-#define SKY_ENGINE_CORE_DOM_MICROTASK_H_
-
-#include "base/callback_forward.h"
-#include "sky/engine/public/platform/WebThread.h"
-#include "sky/engine/wtf/PassOwnPtr.h"
-
-namespace blink {
-
-class Microtask {
-public:
-    static void performCheckpoint();
-    static void enqueueMicrotask(PassOwnPtr<WebThread::Task>);
-    static void enqueueMicrotask(const base::Closure&);
-
-private:
-    explicit Microtask();
-};
-
-} // namespace blink
-
-#endif  // SKY_ENGINE_CORE_DOM_MICROTASK_H_

sky/engine/core/painting/CanvasColor.cpp

@@ -6,7 +6,6 @@
 
 #include "sky/engine/core/script/dom_dart_state.h"
 #include "sky/engine/tonic/dart_error.h"
-#include "sky/engine/tonic/dart_value.h"
 
 namespace blink {
 

sky/engine/core/painting/RRect.cpp

@@ -6,7 +6,6 @@
 
 #include "sky/engine/core/script/dom_dart_state.h"
 #include "sky/engine/tonic/dart_error.h"
-#include "sky/engine/tonic/dart_value.h"
 
 namespace blink {
 

sky/engine/core/painting/RSTransform.cpp

@@ -6,7 +6,6 @@
 
 #include "sky/engine/core/script/dom_dart_state.h"
 #include "sky/engine/tonic/dart_error.h"
-#include "sky/engine/tonic/dart_value.h"
 #include "base/logging.h"
 
 namespace blink {

sky/engine/core/painting/Rect.cpp

@@ -6,7 +6,6 @@
 
 #include "sky/engine/core/script/dom_dart_state.h"
 #include "sky/engine/tonic/dart_error.h"
-#include "sky/engine/tonic/dart_value.h"
 #include "base/logging.h"
 
 namespace blink {

sky/engine/core/script/dart_controller.h

@@ -22,7 +22,6 @@ class DartUI;
 class DOMDartState;
 class DartLibraryProvider;
 class DartSnapshotLoader;
-class DartValue;
 class View;
 
 class DartController {

sky/engine/tonic/BUILD.gn

@@ -33,6 +33,8 @@ source_set("tonic") {
     "dart_library_natives.h",
     "dart_library_provider.cc",
     "dart_library_provider.h",
+    "dart_microtask_queue.cc",
+    "dart_microtask_queue.h",
     "dart_persistent_value.cc",
     "dart_persistent_value.h",
     "dart_snapshot_loader.cc",
@@ -45,8 +47,6 @@ source_set("tonic") {
     "dart_string_cache.h",
     "dart_timer_heap.cc",
     "dart_timer_heap.h",
-    "dart_value.cc",
-    "dart_value.h",
     "dart_wrappable.cc",
     "dart_wrappable.h",
     "dart_wrapper_info.h",

sky/engine/tonic/dart_converter.h

@@ -9,7 +9,6 @@
 #include "sky/engine/tonic/dart_state.h"
 #include "sky/engine/tonic/dart_string.h"
 #include "sky/engine/tonic/dart_string_cache.h"
-#include "sky/engine/tonic/dart_value.h"
 #include "sky/engine/wtf/text/StringUTF8Adaptor.h"
 #include "sky/engine/wtf/text/WTFString.h"
 
@@ -345,30 +344,6 @@ struct DartConverter<Vector<T>> {
   }
 };
 
-////////////////////////////////////////////////////////////////////////////////
-// DartValue
-
-template <>
-struct DartConverter<DartValue*> {
-  static Dart_Handle ToDart(DartState* state, DartValue* val) {
-    return val->dart_value();
-  }
-
-  static void SetReturnValue(Dart_NativeArguments args, DartValue* val) {
-    Dart_SetReturnValue(args, val->dart_value());
-  }
-
-  static PassRefPtr<DartValue> FromDart(Dart_Handle handle) {
-    return DartValue::Create(DartState::Current(), handle);
-  }
-
-  static PassRefPtr<DartValue> FromArguments(Dart_NativeArguments args,
-                                             int index,
-                                             Dart_Handle& exception) {
-    return FromDart(Dart_GetNativeArgument(args, index));
-  }
-};
-
 
 ////////////////////////////////////////////////////////////////////////////////
 // Dart_Handle

sky/engine/tonic/dart_microtask_queue.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 "sky/engine/tonic/dart_microtask_queue.h"
+
+#include "base/trace_event/trace_event.h"
+#include "sky/engine/tonic/dart_invoke.h"
+#include "sky/engine/tonic/dart_state.h"
+
+namespace blink {
+namespace {
+
+typedef std::vector<DartPersistentValue> MicrotaskQueue;
+
+static MicrotaskQueue& GetQueue() {
+  static MicrotaskQueue* queue = new MicrotaskQueue();
+  return *queue;
+}
+
+}  // namespace
+
+void DartMicrotaskQueue::ScheduleMicrotask(Dart_Handle callback) {
+  GetQueue().emplace_back(DartState::Current(), callback);
+}
+
+void DartMicrotaskQueue::RunMicrotasks() {
+  MicrotaskQueue& queue = GetQueue();
+  while(!queue.empty()) {
+    TRACE_EVENT0("flutter", "DartMicrotaskQueue::RunMicrotasks");
+
+    MicrotaskQueue local;
+    std::swap(queue, local);
+    for (const auto& callback : local) {
+      base::WeakPtr<DartState> dart_state = callback.dart_state();
+      if (!dart_state.get())
+        continue;
+      DartState::Scope dart_scope(dart_state.get());
+      DartInvokeAppClosure(callback.value(), 0, nullptr);
+    }
+  }
+}
+
+}

sky/engine/tonic/dart_microtask_queue.h

+// 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.
+
+#ifndef SKY_ENGINE_TONIC_DART_MICROTASK_QUEUE_H_
+#define SKY_ENGINE_TONIC_DART_MICROTASK_QUEUE_H_
+
+#include "dart/runtime/include/dart_api.h"
+
+namespace blink {
+
+class DartMicrotaskQueue {
+ public:
+  static void ScheduleMicrotask(Dart_Handle callback);
+  static void RunMicrotasks();
+};
+
+}  // namespace blink
+
+#endif  // SKY_ENGINE_TONIC_DART_MICROTASK_QUEUE_H_

sky/engine/tonic/dart_persistent_value.cc

@@ -12,6 +12,13 @@ namespace blink {
 DartPersistentValue::DartPersistentValue() : value_(nullptr) {
 }
 
+DartPersistentValue::DartPersistentValue(DartPersistentValue&& other)
+  : dart_state_(other.dart_state_),
+    value_(other.value_) {
+  other.dart_state_ = base::WeakPtr<DartState>();
+  other.value_ = nullptr;
+}
+
 DartPersistentValue::DartPersistentValue(DartState* dart_state,
                                          Dart_Handle value)
     : value_(nullptr) {

sky/engine/tonic/dart_persistent_value.h

@@ -19,6 +19,7 @@ class DartState;
 class DartPersistentValue {
  public:
   DartPersistentValue();
+  DartPersistentValue(DartPersistentValue&& other);
   DartPersistentValue(DartState* dart_state, Dart_Handle value);
   ~DartPersistentValue();
 

sky/engine/tonic/dart_value.cc

-// Copyright 2015 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 "sky/engine/tonic/dart_value.h"
-
-namespace blink {
-
-DartValue::DartValue() {
-}
-
-DartValue::DartValue(DartState* dart_state, Dart_Handle value)
-    : dart_value_(dart_state, value) {
-}
-
-DartValue::~DartValue() {
-}
-
-bool DartValue::Equals(DartValue* other) const {
-  DCHECK(other);
-  if (is_empty())
-    return other->is_empty();
-  if (other->is_empty())
-    return false;
-  return Dart_IdentityEquals(dart_value(), other->dart_value());
-}
-
-void DartValue::Clear() {
-  dart_value_.Clear();
-}
-
-}  // namespace blink

sky/engine/tonic/dart_value.h

-// Copyright 2015 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 SKY_ENGINE_TONIC_DART_VALUE_H_
-#define SKY_ENGINE_TONIC_DART_VALUE_H_
-
-#include "base/logging.h"
-#include "dart/runtime/include/dart_api.h"
-#include "sky/engine/tonic/dart_persistent_value.h"
-#include "sky/engine/tonic/dart_state.h"
-#include "sky/engine/wtf/PassRefPtr.h"
-#include "sky/engine/wtf/RefCounted.h"
-#include "sky/engine/wtf/RefPtr.h"
-
-namespace blink {
-
-// DartValue is a convience wrapper around DartPersistentValue that lets clients
-// use RefPtr to keep track of the number of references to the underlying Dart
-// object. Be careful when retaining RefPtr<DartValue> in the heap because the
-// VM's garbage collector cannot break cycles that involve the C++ heap, which
-// can lead to memory leaks.
-class DartValue : public RefCounted<DartValue> {
- public:
-  static PassRefPtr<DartValue> Create(DartState* dart_state,
-                                      Dart_Handle value) {
-    return adoptRef(new DartValue(dart_state, value));
-  }
-
-  static PassRefPtr<DartValue> Create() { return adoptRef(new DartValue()); }
-
-  ~DartValue();
-
-  Dart_Handle dart_value() const { return dart_value_.value(); }
-  const base::WeakPtr<DartState>& dart_state() const {
-      return dart_value_.dart_state();
-  }
-
-  bool is_empty() const { return !dart_value(); }
-
-  bool is_null() const {
-    DCHECK(!is_empty());
-    return Dart_IsNull(dart_value());
-  }
-
-  bool is_function() const {
-    DCHECK(!is_empty());
-    return Dart_IsClosure(dart_value());
-  }
-
-  bool Equals(DartValue* other) const;
-  void Clear();
-
- private:
-  DartValue();
-  DartValue(DartState* dart_state, Dart_Handle value);
-
-  DartPersistentValue dart_value_;
-
-  DISALLOW_COPY_AND_ASSIGN(DartValue);
-};
-
-}  // namespace blink
-
-#endif  // SKY_ENGINE_TONIC_DART_VALUE_H_

sky/engine/web/Sky.cpp

@@ -33,12 +33,12 @@
 #include "base/message_loop/message_loop.h"
 #include "base/rand_util.h"
 #include "mojo/message_pump/message_pump_mojo.h"
-#include "sky/engine/core/dom/Microtask.h"
 #include "sky/engine/core/Init.h"
 #include "sky/engine/core/script/dart_init.h"
 #include "sky/engine/platform/LayoutTestSupport.h"
 #include "sky/engine/platform/Logging.h"
 #include "sky/engine/public/platform/Platform.h"
+#include "sky/engine/tonic/dart_microtask_queue.h"
 #include "sky/engine/wtf/Assertions.h"
 #include "sky/engine/wtf/CryptographicallyRandomNumber.h"
 #include "sky/engine/wtf/MainThread.h"
@@ -57,7 +57,7 @@ void willProcessTask()
 
 void didProcessTask()
 {
-    Microtask::performCheckpoint();
+    DartMicrotaskQueue::RunMicrotasks();
     // FIXME: Report memory usage to dart?
 }