Reapply "Move isolate loading to a separate loader isolate."

Source/bindings/dart/DartController.cpp

Index: Source/bindings/dart/DartController.cpp
diff --git a/Source/bindings/dart/DartController.cpp b/Source/bindings/dart/DartController.cpp
index 7e462c0989d4fdec8717c9ddba3c4b341bb5cfe2..779a088a033fc40ce6f15cd328cb61183210147d 100644
--- a/Source/bindings/dart/DartController.cpp
+++ b/Source/bindings/dart/DartController.cpp
@@ -35,6 +35,7 @@
 #include "HTMLNames.h"
 #include "V8Navigator.h"
 #include "bindings/dart/DartApplicationLoader.h"
+#include "bindings/dart/DartAsyncLoader.h"
 #include "bindings/dart/DartDOMData.h"
 #include "bindings/dart/DartDOMWrapper.h"
 #include "bindings/dart/DartDebugServer.h"
@@ -317,57 +318,34 @@ public:
     void dispatchErrorEvent() { }
 };
 
-class ApplicationLoadedCallback : public VoidCallback {
+class DartSpawnLoadCallback : public DartAsyncLoader::LoadCallback {
 public:
-    ApplicationLoadedCallback(Dart_Isolate isolate, PassRefPtr<Document> document) : m_isolate(isolate), m_document(document) { }
-
-    bool handleEvent()
+    DartSpawnLoadCallback(Dart_Isolate isolate, const String& url, Document* originDocument)
+        : LoadCallback(originDocument)
+        , m_isolate(isolate)
+        , m_url(url)
     {
-        ASSERT(isMainThread());
-        ASSERT(Dart_CurrentIsolate() == m_isolate);
-
-        Dart_ExitIsolate();
-        Dart_IsolateMakeRunnable(m_isolate);
-        Dart_EnterIsolate(m_isolate);
-
-        return true;
     }
 
-private:
-    Dart_Isolate m_isolate;
-    RefPtr<Document> m_document;
-};
-
-class LoadIsolateSourcesTask : public ScriptExecutionContext::Task {
-public:
-    LoadIsolateSourcesTask(const char* url, Dart_Isolate isolate, Document* document)
-        : m_url(strdup(url)), m_isolate(isolate), m_document(document)
-    { }
-
-    ~LoadIsolateSourcesTask()
+    void ready(PassRefPtr<DartAsyncLoader> loader)
     {
-        free(m_url);
-    }
+        RefPtr<DartAsyncLoader> asyncLoader = loader;
+        RefPtr<SpawnUriErrorEventDispatcher> errorEventDispatcher = adoptRef(new SpawnUriErrorEventDispatcher());
 
-    virtual void performTask(ScriptExecutionContext* context)
-    {
-        ASSERT(isMainThread());
+        RefPtr<DartApplicationLoader> applicationLoader = adoptRef(new DartApplicationLoader(m_isolate, document(), errorEventDispatcher, asyncLoader, false));
 
-        RefPtr<SpawnUriErrorEventDispatcher> errorEventDispatcher = adoptRef(new SpawnUriErrorEventDispatcher());
-        RefPtr<VoidCallback> applicationLoadedCallback = adoptRef(new ApplicationLoadedCallback(m_isolate, m_document));
-        RefPtr<DartApplicationLoader> applicationLoader = adoptRef(new DartApplicationLoader(m_isolate, m_document, errorEventDispatcher, applicationLoadedCallback, false));
-        applicationLoader->loadScriptResource(m_url);
+        applicationLoader->load(asyncLoader->scriptUrl(), asyncLoader->scriptSource(), asyncLoader->scriptLineNumber());
+        Dart_IsolateMakeRunnable(m_isolate);
     }
 
 private:
-    char* const m_url;
-    const Dart_Isolate m_isolate;
-    Document* m_document;
+    Dart_Isolate m_isolate;
+    String m_url;
 };
 
 Dart_Isolate DartController::createPureIsolateCallback(const char* scriptURL, const char* entryPoint, void* data, char** errorMsg)
 {
-    bool needApplicationLoader = false;
+    bool needAsyncLoader = false;
 
     {
         DartApiScope apiScope;
@@ -389,7 +367,7 @@ Dart_Isolate DartController::createPureIsolateCallback(const char* scriptURL, co
             return 0;
         }
 
-        needApplicationLoader = strcmp(scriptURL, parentIsolateURL);
+        needAsyncLoader = strcmp(scriptURL, parentIsolateURL);
     }
 
     DartDOMData* parentDOMData = static_cast<DartDOMData*>(data);
@@ -401,8 +379,12 @@ Dart_Isolate DartController::createPureIsolateCallback(const char* scriptURL, co
     if (!isolate)
         return 0;
 
-    if (needApplicationLoader) {
-        context->postTask(adoptPtr(new LoadIsolateSourcesTask(scriptURL, isolate, document)));
+    if (needAsyncLoader) {
+        // We need to request the sources asynchronously.
+        RefPtr<DartSpawnLoadCallback> callback = adoptRef(new DartSpawnLoadCallback(isolate, scriptURL, document));
+        // A DartAsyncLoader will delete itself once all resources are fetched.
+        DartAsyncLoader* asyncLoader = new DartAsyncLoader(scriptURL, callback);
+        asyncLoader->fetchScriptResource(scriptURL);
         Dart_ExitIsolate();
     } else {
         // FIXME: avoid copying parent snapshot.
@@ -556,7 +538,6 @@ bool DartController::isDartMimeType(const String& mimeType)
     return !mimeType.isEmpty() && types.contains(mimeType);
 }
 
-
 class DartScriptRunner : public EventListener {
 public:
     static PassRefPtr<DartScriptRunner> create()
@@ -659,6 +640,11 @@ public:
         return m_scriptElement->startLineNumber();
     }
 
+    ScriptLoader* loader()
+    {
+        return m_scriptElement;
+    }
+
     virtual ~ScriptElementProxy() { }
 
 protected:
@@ -728,6 +714,42 @@ private:
     }
 };
 
+class DartDomLoadCallback : public DartAsyncLoader::LoadCallback {
+public:
+    DartDomLoadCallback(DartController* controller, const String& url, Document* originDocument, PassRefPtr<ScriptElementProxy> proxy)
+        : LoadCallback(originDocument, proxy->loader())
+        , m_controller(controller)
+        , m_url(url)
+        , m_proxy(proxy)
+    {
+    }
+
+    void ready(PassRefPtr<DartAsyncLoader> asyncLoader)
+    {
+        m_controller->loadAndRunScript(m_url, asyncLoader, m_proxy);
+    }
+
+private:
+    DartController* m_controller;
+    String m_url;
+    RefPtr<ScriptElementProxy> m_proxy;
+};
+
+void DartController::loadAndRunScript(const String& url, PassRefPtr<DartAsyncLoader> loader, PassRefPtr<ScriptElementProxy> proxy)
+{
+    RefPtr<DartAsyncLoader> asyncLoader = loader;
+    Document* document = frame()->document();
+
+    createDOMEnabledIsolate(url, "main", document);
+
+    // FIXME: it may make sense to ensure that we'll never call evaluate more than once for the same script tag.
+    RefPtr<DartApplicationLoader> applicationLoader = adoptRef(new DartApplicationLoader(Dart_CurrentIsolate(), document, proxy, asyncLoader));
+    applicationLoader->load(asyncLoader->scriptUrl(), asyncLoader->scriptSource(), asyncLoader->scriptLineNumber());
+
+    Dart_ExitIsolate();
+}
+
+
 void DartController::loadScripts()
 {
     if (m_scriptsLoaded)
@@ -754,16 +776,18 @@ void DartController::loadScripts()
             continue;
 
         String scriptURL = scriptElementProxy->sourceAttributeValue();
-        createDOMEnabledIsolate(scriptURL, "main", document);
+        String url = scriptURL.isEmpty() ? document->url() : scriptURL;
+
+        RefPtr<DartDomLoadCallback> callback = adoptRef(new DartDomLoadCallback(this, url, document, scriptElementProxy));
 
-        // FIXME: it may make sense to ensure that we'll never call evaluate more than once for the same script tag.
-        RefPtr<DartApplicationLoader> applicationLoader = adoptRef(new DartApplicationLoader(Dart_CurrentIsolate(), document, scriptElementProxy));
+        // A DartAsyncLoader will delete itself once all resources are fetched.
+        DartAsyncLoader* asyncLoader = new DartAsyncLoader(url, callback);
+        WTF::OrdinalNumber startLineNumber = scriptElementProxy->startLineNumber();
+        intptr_t lineOffset = startLineNumber == OrdinalNumber::beforeFirst() ? 0 : startLineNumber.zeroBasedInt();
         if (scriptURL.isEmpty())
-            applicationLoader->load(m_frame->document()->url(), scriptElementProxy->scriptContent(), scriptElementProxy->startLineNumber());
+            asyncLoader->process(m_frame->document()->url(), scriptElementProxy->scriptContent(), lineOffset);
         else
-            applicationLoader->loadScriptResource(scriptURL);
-
-        Dart_ExitIsolate();
+            asyncLoader->fetchScriptResource(scriptURL);
     }
 
     m_scriptsLoaded = true;