Makes WebThreadSupportingGC constructible for an existing thread

Source/modules/compositorworker/CompositorWorkerManager.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "modules/compositorworker/CompositorWorkerManager.h"
 
 #include "bindings/core/v8/V8Binding.h"
 #include "bindings/core/v8/V8GCController.h"
 #include "bindings/core/v8/V8Initializer.h"
 #include "bindings/core/v8/V8PerIsolateData.h"
 #include "platform/ThreadSafeFunctional.h"
 #include "platform/WebThreadSupportingGC.h"
 #include "wtf/MainThread.h"
 #include "wtf/ThreadingPrimitives.h"
 
 namespace blink {
 
 namespace {
 
 static CompositorWorkerManager* s_instance = nullptr;
 
-static Mutex& singletonMutex()
+Mutex& singletonMutex()
 {
     AtomicallyInitializedStaticReference(Mutex, mutex, new Mutex);
     return mutex;
 }
 
-static void destroyThread(WebThreadSupportingGC* thread)
+void destroyThread(WebThread* thread)
 {
     delete thread;
 }
 
 } // namespace
 
 void CompositorWorkerManager::initialize()
 {
     MutexLocker lock(singletonMutex());
     ASSERT(!s_instance);
@@ skipping 22 matching lines @@
 CompositorWorkerManager::~CompositorWorkerManager()
 {
 }
 
 WebThreadSupportingGC& CompositorWorkerManager::compositorWorkerThread()
 {
     MutexLocker lock(m_mutex);
     if (!m_thread) {
         ASSERT(isMainThread());
         ASSERT(!m_workerCount);
-        m_thread = WebThreadSupportingGC::create("CompositorWorker Thread");
+        // TODO(sadrul): Instead of creating a new thread, retrieve the thread from
+        // Platform using a more specialized function
+        // (e.g. Platform::compositorWorkerThread()).
+        m_platformThread = adoptPtr(Platform::current()->createThread("CompositorWorker Thread"));
+        m_thread = WebThreadSupportingGC::createForThread(m_platformThread.get());
     }
     return *m_thread.get();
 }
 
 void CompositorWorkerManager::initializeBackingThread()
 {
     ASSERT(m_thread->isCurrentThread());
     MutexLocker lock(m_mutex);
     ++m_workerCount;
     if (m_workerCount > 1)
@@ skipping 12 matching lines @@
 }
 
 void CompositorWorkerManager::shutdownBackingThread()
 {
     MutexLocker lock(m_mutex);
     ASSERT(m_thread->isCurrentThread());
     ASSERT(m_workerCount > 0);
     --m_workerCount;
     if (m_workerCount == 0) {
         m_thread->shutdown();
-        Platform::current()->mainThread()->postTask(FROM_HERE, threadSafeBind(destroyThread, AllowCrossThreadAccess(m_thread.leakPtr())));
+        Platform::current()->mainThread()->postTask(FROM_HERE, threadSafeBind(destroyThread, AllowCrossThreadAccess(m_platformThread.leakPtr())));
         m_thread = nullptr;

[haraken, 2015/09/01 09:32:37]

Nit: We may want to run m_thread=nullptr before posting a task to destruct
m_thread and m_platformThread in the reverse order in which they are created.

[kinuko, 2015/09/01 09:48:56]

Done.

     }
 }
 
 v8::Isolate* CompositorWorkerManager::initializeIsolate()
 {
     MutexLocker lock(m_mutex);
     ASSERT(m_thread->isCurrentThread());
     ASSERT(m_isolate);
     // It is safe to use the existing isolate even if TerminateExecution() has been
     // called on it, without calling CancelTerminateExecution().
@@ skipping 22 matching lines @@
 {
     MutexLocker lock(m_mutex);
     ASSERT(isMainThread());
     if (m_workerCount > 1)
         return;
 
     v8::V8::TerminateExecution(m_isolate);
 }
 
 } // namespace blink