Implement WebThreadSupportingGC, which wraps a WebThread attached to Oilpan's GC

Source/core/workers/WorkerThread.cpp

 /*
  * Copyright (C) 2008 Apple 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 206 matching lines @@
     MutexLocker lock(threadSetMutex());
     ASSERT(workerThreads().contains(this));
     workerThreads().remove(this);
 }
 
 void WorkerThread::start()
 {
     if (m_thread)
         return;
 
-    m_thread = adoptPtr(blink::Platform::current()->createThread("WebCore: Worker"));
+    m_thread = WebThreadRunner::create("WebCore: Worker");
     m_thread->postTask(new Task(WTF::bind(&WorkerThread::initialize, this)));
 }
 
 void WorkerThread::interruptAndDispatchInspectorCommands()
 {
     MutexLocker locker(m_workerInspectorControllerMutex);
     if (m_workerInspectorController)
         m_workerInspectorController->interruptAndDispatchInspectorCommands();
 }
 
 void WorkerThread::initialize()
 {
     KURL scriptURL = m_startupData->m_scriptURL;
     String sourceCode = m_startupData->m_sourceCode;
     WorkerThreadStartMode startMode = m_startupData->m_startMode;
     m_microtaskRunner = adoptPtr(new MicrotaskRunner);
     m_thread->addTaskObserver(m_microtaskRunner.get());
 
     {
         MutexLocker lock(m_threadCreationMutex);
 
-        m_pendingGCRunner = adoptPtr(new PendingGCRunner);
-        m_messageLoopInterruptor = adoptPtr(new MessageLoopInterruptor(m_thread.get()));
-        m_thread->addTaskObserver(m_pendingGCRunner.get());
-        ThreadState::attach();
-        ThreadState::current()->addInterruptor(m_messageLoopInterruptor.get());
+        m_thread->attachGC();
         m_workerGlobalScope = createWorkerGlobalScope(m_startupData.release());
 
         m_sharedTimer = adoptPtr(new WorkerSharedTimer(this));
         PlatformThreadData::current().threadTimers().setSharedTimer(m_sharedTimer.get());
 
         if (m_terminated) {
             // The worker was terminated before the thread had a chance to run. Since the context didn't exist yet,
             // forbidExecution() couldn't be called from stop().
             m_workerGlobalScope->script()->forbidExecution();
         }
@@ skipping 25 matching lines @@
 
     // The below assignment will destroy the context, which will in turn notify messaging proxy.
     // We cannot let any objects survive past thread exit, because no other thread will run GC or otherwise destroy them.
     // If Oilpan is enabled, we detach of the context/global scope, with the final heap cleanup below sweeping it out.
 #if !ENABLE(OILPAN)
     ASSERT(m_workerGlobalScope->hasOneRef());
 #endif
     m_workerGlobalScope->dispose();
     m_workerGlobalScope = nullptr;
 
-    ThreadState::current()->removeInterruptor(m_messageLoopInterruptor.get());
-
-    // Detach the ThreadState, cleaning out the thread's heap by
-    // performing a final GC. The cleanup operation will at the end
-    // assert that the heap is empty. If the heap does not become
-    // empty, there are still pointers into the heap and those
-    // pointers will be dangling after thread termination because we
-    // are destroying the heap. It is important to detach while the
-    // thread is still valid. In particular, finalizers for objects in
-    // the heap for this thread will need to access thread local data.
-    ThreadState::detach();
+    m_thread->detachGC();
 
     m_thread->removeTaskObserver(m_microtaskRunner.get());
     m_microtaskRunner = nullptr;
-    m_thread->removeTaskObserver(m_pendingGCRunner.get());
-    m_pendingGCRunner = nullptr;
-    m_messageLoopInterruptor = nullptr;
 
     // Notify the proxy that the WorkerGlobalScope has been disposed of.
     // This can free this thread object, hence it must not be touched afterwards.
     workerReportingProxy().workerGlobalScopeDestroyed();
 
     // Clean up PlatformThreadData before WTF::WTFThreadData goes away!
     PlatformThreadData::current().destroy();
 }
 
 class WorkerThreadShutdownFinishTask : public ExecutionContextTask {
@@ skipping 138 matching lines @@
     InspectorInstrumentation::didLeaveNestedRunLoop(m_workerGlobalScope.get());
 }
 
 void WorkerThread::setWorkerInspectorController(WorkerInspectorController* workerInspectorController)
 {
     MutexLocker locker(m_workerInspectorControllerMutex);
     m_workerInspectorController = workerInspectorController;
 }
 
 } // namespace blink