Oilpan: Remove raw pointer to InProcessWorkerBase from WorkerMessagingProxy

Source/core/workers/WorkerMessagingProxy.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009 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
@@ skipping 63 matching lines @@
     , m_unconfirmedMessageCount(0)
     , m_workerThreadHadPendingActivity(false)
     , m_askedToTerminate(false)
     , m_workerInspectorProxy(WorkerInspectorProxy::create())
     , m_workerClients(workerClients)
 {
     ASSERT(m_workerObject);
     ASSERT((m_executionContext->isDocument() && isMainThread())
         || (m_executionContext->isWorkerGlobalScope() && toWorkerGlobalScope(m_executionContext.get())->thread()->isCurrentThread()));
     m_workerInspectorProxy->setWorkerGlobalScopeProxy(this);
+#if ENABLE(OILPAN)
+    m_keepAlive = adoptPtr(new Persistent<WorkerMessagingProxy>(this));
+#endif
 }
 
 WorkerMessagingProxy::~WorkerMessagingProxy()
 {
     ASSERT(!m_workerObject);
+#if !ENABLE(OILPAN)
     ASSERT((m_executionContext->isDocument() && isMainThread())
         || (m_executionContext->isWorkerGlobalScope() && toWorkerGlobalScope(m_executionContext.get())->thread()->isCurrentThread()));
+#endif
     if (m_loaderProxy)
         m_loaderProxy->detachProvider(this);
 }
 
 void WorkerMessagingProxy::startWorkerGlobalScope(const KURL& scriptURL, const String& userAgent, const String& sourceCode, WorkerThreadStartMode startMode)
 {
     // FIXME: This need to be revisited when we support nested worker one day
     ASSERT(m_executionContext->isDocument());
     if (m_askedToTerminate) {
         // Worker.terminate() could be called from JS before the thread was created.
@@ skipping 114 matching lines @@
         workerThreadTerminated();
 }
 
 void WorkerMessagingProxy::workerThreadTerminated()
 {
     // This method is always the last to be performed, so the proxy is not needed for communication
     // in either side any more. However, the Worker object may still exist, and it assumes that the proxy exists, too.
     m_askedToTerminate = true;
     m_workerThread = nullptr;
     terminateInternally();
-    if (m_mayBeDestroyed)
+    if (m_mayBeDestroyed) {
+#if ENABLE(OILPAN)
+        m_keepAlive.release();
+#else
         delete this;
+#endif
+    }
 }
 
 void WorkerMessagingProxy::terminateWorkerGlobalScope()
 {
     if (m_askedToTerminate)
         return;
     m_askedToTerminate = true;
 
     if (m_workerThread)
         m_workerThread->terminate();
@@ skipping 48 matching lines @@
     m_workerInspectorProxy->workerThreadTerminated();
 
     // FIXME: This need to be revisited when we support nested worker one day
     ASSERT(m_executionContext->isDocument());
     Document* document = toDocument(m_executionContext.get());
     LocalFrame* frame = document->frame();
     if (frame)
         frame->console().adoptWorkerMessagesAfterTermination(this);
 }
 
+void WorkerMessagingProxy::clearWeakMembers(Visitor* visitor)
+{
+    if (Heap::isHeapObjectAlive(m_workerObject))
+        return;
+    workerObjectDestroyed();

[haraken, 2015/07/30 11:46:31]

It is not nice to call workerObjectDestroyed() in weak processing, since the
weak processing is not called if the WorkerMessagingProxy and the
InProcessWorkerBase die at the same time.

I think we should call workerObjectDestroyed() in the pre-finalizer of
InProcessWorkerBase. Then workerObjectDestroyed() will be unconditionally called
before the InProcessWorkerBase gets destructed.

+}
+
+DEFINE_TRACE(WorkerMessagingProxy)
+{
+    visitor->trace(m_executionContext);
+    visitor->trace(m_workerClients);
+    visitor->template registerWeakMembers<WorkerMessagingProxy, &WorkerMessagingProxy::clearWeakMembers>(this);
+    WorkerGlobalScopeProxy::trace(visitor);
+}
+
 } // namespace blink