use v8 Microtask Queue

Source/core/dom/Microtask.cpp

Index: Source/core/dom/Microtask.cpp
diff --git a/Source/core/dom/Microtask.cpp b/Source/core/dom/Microtask.cpp
index a70aed8750b311b5d5d0b2637b65ae94d766596d..bbfb00df0df387155ff21d0dc56ec1f724c3547b 100644
--- a/Source/core/dom/Microtask.cpp
+++ b/Source/core/dom/Microtask.cpp
@@ -33,39 +33,48 @@
 
 #include "bindings/v8/V8PerIsolateData.h"
 #include "wtf/Vector.h"
+#include <v8.h>
 
 namespace WebCore {
 
-typedef Vector<MicrotaskCallback> MicrotaskQueue;
-
-static MicrotaskQueue& microtaskQueue()
-{
-    DEFINE_STATIC_LOCAL(MicrotaskQueue, microtaskQueue, ());
-    return microtaskQueue;
-}
-
 void Microtask::performCheckpoint()
 {
-    V8PerIsolateData* isolateData = V8PerIsolateData::current();
+    v8::Isolate* isolate = v8::Isolate::GetCurrent();
+    V8PerIsolateData* isolateData = V8PerIsolateData::from(isolate);
     ASSERT(isolateData);
     if (isolateData->recursionLevel() || isolateData->performingMicrotaskCheckpoint())
         return;
     isolateData->setPerformingMicrotaskCheckpoint(true);
 
-    while (!microtaskQueue().isEmpty()) {
-        Vector<MicrotaskCallback> microtasks;
-        microtasks.swap(microtaskQueue());
-        for (size_t i = 0; i < microtasks.size(); ++i) {
-            microtasks[i]();
-        }
-    }
+    v8::HandleScope handleScope(isolate);
+    v8::Local<v8::Context> context = isolateData->ensureDomInJSContext();
+    v8::Context::Scope scope(context);
+    v8::V8::RunMicrotasks(isolate);
 
     isolateData->setPerformingMicrotaskCheckpoint(false);
 }
 
+COMPILE_ASSERT(sizeof(void*) == sizeof(MicrotaskCallback), VoidPtrAndFunctionPtrAreSameSize);
+
+static void microtaskFunctionCallback(const v8::FunctionCallbackInfo<v8::Value>& info)
+{
+    MicrotaskCallback callback =
+        reinterpret_cast<MicrotaskCallback>(reinterpret_cast<intptr_t>(
+            info.Data().As<v8::External>()->Value()));
+    (*callback)();
+}
+
 void Microtask::enqueueMicrotask(MicrotaskCallback callback)
 {
-    microtaskQueue().append(callback);
+    v8::Isolate* isolate = v8::Isolate::GetCurrent();
+    V8PerIsolateData* isolateData = V8PerIsolateData::from(isolate);
+    v8::HandleScope handleScope(isolate);
+    v8::Local<v8::Context> context = isolateData->ensureDomInJSContext();
+    v8::Context::Scope scope(context);
+    v8::Local<v8::External> handler =
+        v8::External::New(isolate,
+            reinterpret_cast<void*>(reinterpret_cast<intptr_t>(callback)));
+    v8::V8::EnqueueMicrotask(isolate, v8::Function::New(isolate, &microtaskFunctionCallback, handler));
 }
 
 } // namespace WebCore