Oilpan: have PendingScripts trace their script elements.

Source/core/dom/ScriptRunner.cpp

 /*
  * Copyright (C) 2010 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
@@ skipping 13 matching lines @@
  */
 
 #include "config.h"
 #include "core/dom/ScriptRunner.h"
 
 #include "core/dom/Document.h"
 #include "core/dom/Element.h"
 #include "core/dom/PendingScript.h"
 #include "core/dom/ScriptLoader.h"
 #include "core/fetch/ScriptResource.h"
+#include "platform/heap/Handle.h"
 
 namespace WebCore {
 
 ScriptRunner::ScriptRunner(Document* document)
     : m_document(document)
     , m_timer(this, &ScriptRunner::timerFired)
 {
     ASSERT(document);
 }
 
 ScriptRunner::~ScriptRunner()
 {
-    for (size_t i = 0; i < m_scriptsToExecuteSoon.size(); ++i)

[eseidel, 2014/05/28 22:43:38]

Wow this code is scary.

-        m_document->decrementLoadEventDelayCount();
-    for (size_t i = 0; i < m_scriptsToExecuteInOrder.size(); ++i)
-        m_document->decrementLoadEventDelayCount();
-    for (size_t i = 0; i < m_pendingAsyncScripts.size(); ++i)
-        m_document->decrementLoadEventDelayCount();

[haraken, 2014/05/29 01:46:08]

Just help me understand: I agree that we no longer need this code in oilpan
builds because the Document and the ScriptRunner die together, but why can we
remove the code in non-oilpan builds?

[sof, 2014/05/29 06:02:07]

For the same reason, essentially. The ScriptRunner is OwnPtr'ed by the Document
and only released on Document destruct. Decrementing counts and attempting to
possibly schedule a future load event using a near-dead Document isn't
productive work. I didn't see the value of keeping it.

 }
 
 void ScriptRunner::queueScriptForExecution(ScriptLoader* scriptLoader, ResourcePtr<ScriptResource> resource, ExecutionType executionType)
 {
     ASSERT(scriptLoader);
     ASSERT(resource.get());
 
     Element* element = scriptLoader->element();
     ASSERT(element);
     ASSERT(element->inDocument());
@@ skipping 49 matching lines @@
     case IN_ORDER_EXECUTION:
         ASSERT(!m_scriptsToExecuteInOrder.isEmpty());
         break;
     }
 }
 
 void ScriptRunner::timerFired(Timer<ScriptRunner>* timer)
 {
     ASSERT_UNUSED(timer, timer == &m_timer);
 
-    RefPtr<Document> protect(m_document);
+    RefPtrWillBeRawPtr<Document> protect(m_document.get());
 
     Vector<PendingScript> scripts;
     scripts.swap(m_scriptsToExecuteSoon);
 
     size_t numInOrderScriptsToExecute = 0;
     for (; numInOrderScriptsToExecute < m_scriptsToExecuteInOrder.size() && m_scriptsToExecuteInOrder[numInOrderScriptsToExecute].resource()->isLoaded(); ++numInOrderScriptsToExecute)
         scripts.append(m_scriptsToExecuteInOrder[numInOrderScriptsToExecute]);
     if (numInOrderScriptsToExecute)
         m_scriptsToExecuteInOrder.remove(0, numInOrderScriptsToExecute);
 
     size_t size = scripts.size();
     for (size_t i = 0; i < size; ++i) {
         ScriptResource* resource = scripts[i].resource();
-        RefPtr<Element> element = scripts[i].releaseElementAndClear();
+        RefPtrWillBeRawPtr<Element> element = scripts[i].releaseElementAndClear();
         toScriptLoaderIfPossible(element.get())->execute(resource);
         m_document->decrementLoadEventDelayCount();
     }
 }
 
+void ScriptRunner::trace(Visitor* visitor)
+{
+    visitor->trace(m_document);
+    visitor->trace(m_scriptsToExecuteInOrder);
+    visitor->trace(m_scriptsToExecuteSoon);
+    visitor->trace(m_pendingAsyncScripts);
 }
+
+}