Source/modules/websockets/WorkerThreadableWebSocketChannel.cpp - platform/external/chromium_org/third_party/WebKit - Git at Google

 /*
  * Copyright (C) 2011, 2012 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"

 #include "modules/websockets/WorkerThreadableWebSocketChannel.h"

 #include "bindings/core/v8/ScriptCallStackFactory.h"
 #include "core/dom/CrossThreadTask.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/fileapi/Blob.h"
 #include "core/inspector/ScriptCallFrame.h"
 #include "core/inspector/ScriptCallStack.h"
 #include "core/workers/WorkerLoaderProxy.h"
 #include "core/workers/WorkerThread.h"
 #include "modules/websockets/MainThreadWebSocketChannel.h"
 #include "modules/websockets/NewWebSocketChannelImpl.h"
 #include "modules/websockets/ThreadableWebSocketChannelClientWrapper.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebWaitableEvent.h"
 #include "wtf/ArrayBuffer.h"
 #include "wtf/Assertions.h"
 #include "wtf/Functional.h"
 #include "wtf/MainThread.h"

 namespace blink {

 typedef WorkerThreadableWebSocketChannel::Bridge Bridge;
 typedef WorkerThreadableWebSocketChannel::Peer Peer;

 // Created and destroyed on the worker thread. All setters of this class are
 // called on the main thread, while all getters are called on the worker
 // thread. signalWorkerThread() must be called before any getters are called.
 class ThreadableWebSocketChannelSyncHelper : public GarbageCollectedFinalized<ThreadableWebSocketChannelSyncHelper> {
 public:
     static ThreadableWebSocketChannelSyncHelper* create(PassOwnPtr<WebWaitableEvent> event)
     {
         return new ThreadableWebSocketChannelSyncHelper(event);
     }

     ~ThreadableWebSocketChannelSyncHelper()
     {
     }

     // All setters are called on the main thread.
     void setConnectRequestResult(bool connectRequestResult)
     {
         m_connectRequestResult = connectRequestResult;
     }

     // All getter are called on the worker thread.
     bool connectRequestResult() const
     {
         return m_connectRequestResult;
     }

     // This should be called after all setters are called and before any
     // getters are called.
     void signalWorkerThread()
     {
         m_event->signal();
     }
     void wait()
     {
         m_event->wait();
     }

     void trace(Visitor* visitor) { }

 private:
     explicit ThreadableWebSocketChannelSyncHelper(PassOwnPtr<WebWaitableEvent> event)
         : m_event(event)
         , m_connectRequestResult(false)
     {
     }

     OwnPtr<WebWaitableEvent> m_event;
     bool m_connectRequestResult;
 };

 WorkerThreadableWebSocketChannel::WorkerThreadableWebSocketChannel(WorkerGlobalScope& workerGlobalScope, WebSocketChannelClient* client, const String& sourceURL, unsigned lineNumber)
     : m_workerClientWrapper(ThreadableWebSocketChannelClientWrapper::create(client))
     , m_bridge(Bridge::create(m_workerClientWrapper, workerGlobalScope))
     , m_sourceURLAtConnection(sourceURL)
     , m_lineNumberAtConnection(lineNumber)
 {
     ASSERT(m_workerClientWrapper.get());
     m_bridge->initialize(sourceURL, lineNumber);
 }

 WorkerThreadableWebSocketChannel::~WorkerThreadableWebSocketChannel()
 {
     ASSERT(!m_bridge);
 }

 bool WorkerThreadableWebSocketChannel::connect(const KURL& url, const String& protocol)
 {
     ASSERT(m_bridge);
     return m_bridge->connect(url, protocol);
 }

 void WorkerThreadableWebSocketChannel::send(const String& message)
 {
     ASSERT(m_bridge);
     m_bridge->send(message);
 }

 void WorkerThreadableWebSocketChannel::send(const ArrayBuffer& binaryData, unsigned byteOffset, unsigned byteLength)
 {
     ASSERT(m_bridge);
     m_bridge->send(binaryData, byteOffset, byteLength);
 }

 void WorkerThreadableWebSocketChannel::send(PassRefPtr<BlobDataHandle> blobData)
 {
     ASSERT(m_bridge);
     m_bridge->send(blobData);
 }

 void WorkerThreadableWebSocketChannel::close(int code, const String& reason)
 {
     ASSERT(m_bridge);
     m_bridge->close(code, reason);
 }

 void WorkerThreadableWebSocketChannel::fail(const String& reason, MessageLevel level, const String& sourceURL, unsigned lineNumber)
 {
     if (!m_bridge)
         return;

     RefPtrWillBeRawPtr<ScriptCallStack> callStack = createScriptCallStack(1, true);
     if (callStack && callStack->size())  {
         // In order to emulate the ConsoleMessage behavior,
         // we should ignore the specified url and line number if
         // we can get the JavaScript context.
         m_bridge->fail(reason, level, callStack->at(0).sourceURL(), callStack->at(0).lineNumber());
     } else if (sourceURL.isEmpty() && !lineNumber) {
         // No information is specified by the caller - use the url
         // and the line number at the connection.
         m_bridge->fail(reason, level, m_sourceURLAtConnection, m_lineNumberAtConnection);
     } else {
         // Use the specified information.
         m_bridge->fail(reason, level, sourceURL, lineNumber);
     }
 }

 void WorkerThreadableWebSocketChannel::disconnect()
 {
     m_bridge->disconnect();
     m_bridge.clear();
 }

 void WorkerThreadableWebSocketChannel::trace(Visitor* visitor)
 {
     visitor->trace(m_bridge);
     visitor->trace(m_workerClientWrapper);
     WebSocketChannel::trace(visitor);
 }

 Peer::Peer(ThreadableWebSocketChannelClientWrapper* clientWrapper, WorkerLoaderProxy& loaderProxy, ThreadableWebSocketChannelSyncHelper* syncHelper)
     : m_workerClientWrapper(clientWrapper)
     , m_loaderProxy(loaderProxy)
     , m_mainWebSocketChannel(nullptr)
     , m_syncHelper(syncHelper)
 {
     ASSERT(!isMainThread());
 }

 Peer::~Peer()
 {
     ASSERT(!isMainThread());
 }

 Peer* Peer::create(ThreadableWebSocketChannelClientWrapper* clientWrapper, WorkerLoaderProxy& loaderProxy, ThreadableWebSocketChannelSyncHelper* syncHelper)
 {
     return new Peer(clientWrapper, loaderProxy, syncHelper);
 }

 void Peer::initializeInternal(ExecutionContext* context, const String& sourceURL, unsigned lineNumber)
 {
     ASSERT(isMainThread());
     Document* document = toDocument(context);
     if (RuntimeEnabledFeatures::experimentalWebSocketEnabled()) {
         m_mainWebSocketChannel = NewWebSocketChannelImpl::create(document, this, sourceURL, lineNumber);
     } else {
         m_mainWebSocketChannel = MainThreadWebSocketChannel::create(document, this, sourceURL, lineNumber);
     }
     m_syncHelper->signalWorkerThread();
 }

 void Peer::connect(const KURL& url, const String& protocol)
 {
     ASSERT(isMainThread());
     ASSERT(m_syncHelper);
     if (!m_mainWebSocketChannel) {
         m_syncHelper->setConnectRequestResult(false);
     } else {
         bool connectRequestResult = m_mainWebSocketChannel->connect(url, protocol);
         m_syncHelper->setConnectRequestResult(connectRequestResult);
     }
     m_syncHelper->signalWorkerThread();
 }

 void Peer::send(const String& message)
 {
     ASSERT(isMainThread());
     if (m_mainWebSocketChannel)
         m_mainWebSocketChannel->send(message);
 }

 void Peer::sendArrayBuffer(PassOwnPtr<Vector<char> > data)
 {
     ASSERT(isMainThread());
     if (m_mainWebSocketChannel)
         m_mainWebSocketChannel->send(data);
 }

 void Peer::sendBlob(PassRefPtr<BlobDataHandle> blobData)
 {
     ASSERT(isMainThread());
     if (m_mainWebSocketChannel)
         m_mainWebSocketChannel->send(blobData);
 }

 void Peer::close(int code, const String& reason)
 {
     ASSERT(isMainThread());
     ASSERT(m_syncHelper);
     if (!m_mainWebSocketChannel)
         return;
     m_mainWebSocketChannel->close(code, reason);
 }

 void Peer::fail(const String& reason, MessageLevel level, const String& sourceURL, unsigned lineNumber)
 {
     ASSERT(isMainThread());
     ASSERT(m_syncHelper);
     if (!m_mainWebSocketChannel)
         return;
     m_mainWebSocketChannel->fail(reason, level, sourceURL, lineNumber);
 }

 void Peer::disconnect()
 {
     ASSERT(isMainThread());
     ASSERT(m_syncHelper);
     if (m_mainWebSocketChannel) {
         m_mainWebSocketChannel->disconnect();
         m_mainWebSocketChannel = nullptr;
     }
     m_syncHelper->signalWorkerThread();
 }

 static void workerGlobalScopeDidConnect(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, const String& subprotocol, const String& extensions)
 {
     ASSERT_UNUSED(context, context->isWorkerGlobalScope());
     workerClientWrapper->didConnect(subprotocol, extensions);
 }

 void Peer::didConnect(const String& subprotocol, const String& extensions)
 {
     ASSERT(isMainThread());
     // It is important to seprate task creation from posting
     // the task. See the above comment.
     OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidConnect, m_workerClientWrapper, subprotocol, extensions);
     m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
 }

 static void workerGlobalScopeDidReceiveMessage(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, const String& message)
 {
     ASSERT_UNUSED(context, context->isWorkerGlobalScope());
     workerClientWrapper->didReceiveMessage(message);
 }

 void Peer::didReceiveMessage(const String& message)
 {
     ASSERT(isMainThread());
     // It is important to seprate task creation from posting
     // the task. See the above comment.
     OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidReceiveMessage, m_workerClientWrapper, message);
     m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
 }

 static void workerGlobalScopeDidReceiveBinaryData(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, PassOwnPtr<Vector<char> > binaryData)
 {
     ASSERT_UNUSED(context, context->isWorkerGlobalScope());
     workerClientWrapper->didReceiveBinaryData(binaryData);
 }

 void Peer::didReceiveBinaryData(PassOwnPtr<Vector<char> > binaryData)
 {
     ASSERT(isMainThread());
     // It is important to seprate task creation from posting
     // the task. See the above comment.
     OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidReceiveBinaryData, m_workerClientWrapper, binaryData);
     m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
 }

 static void workerGlobalScopeDidConsumeBufferedAmount(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, unsigned long consumed)
 {
     ASSERT_UNUSED(context, context->isWorkerGlobalScope());
     workerClientWrapper->didConsumeBufferedAmount(consumed);
 }

 void Peer::didConsumeBufferedAmount(unsigned long consumed)
 {
     ASSERT(isMainThread());
     // It is important to seprate task creation from posting
     // the task. See the above comment.
     OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidConsumeBufferedAmount, m_workerClientWrapper, consumed);
     m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
 }

 static void workerGlobalScopeDidStartClosingHandshake(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper)
 {
     ASSERT_UNUSED(context, context->isWorkerGlobalScope());
     workerClientWrapper->didStartClosingHandshake();
 }

 void Peer::didStartClosingHandshake()
 {
     ASSERT(isMainThread());
     // It is important to seprate task creation from posting
     // the task. See the above comment.
     OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidStartClosingHandshake, m_workerClientWrapper);
     m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
 }

 static void workerGlobalScopeDidClose(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, WebSocketChannelClient::ClosingHandshakeCompletionStatus closingHandshakeCompletion, unsigned short code, const String& reason)
 {
     ASSERT_UNUSED(context, context->isWorkerGlobalScope());
     workerClientWrapper->didClose(closingHandshakeCompletion, code, reason);
 }

 void Peer::didClose(ClosingHandshakeCompletionStatus closingHandshakeCompletion, unsigned short code, const String& reason)
 {
     ASSERT(isMainThread());
     if (m_mainWebSocketChannel) {
         m_mainWebSocketChannel->disconnect();
         m_mainWebSocketChannel = nullptr;
     }
     // It is important to seprate task creation from posting
     // the task. See the above comment.
     OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidClose, m_workerClientWrapper, closingHandshakeCompletion, code, reason);
     m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
 }

 static void workerGlobalScopeDidReceiveMessageError(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper)
 {
     ASSERT_UNUSED(context, context->isWorkerGlobalScope());
     workerClientWrapper->didReceiveMessageError();
 }

 void Peer::didReceiveMessageError()
 {
     ASSERT(isMainThread());
     // It is important to seprate task creation from posting
     // the task. See the above comment.
     OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidReceiveMessageError, m_workerClientWrapper);
     m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
 }

 void Peer::trace(Visitor* visitor)
 {
     visitor->trace(m_workerClientWrapper);
     visitor->trace(m_mainWebSocketChannel);
     visitor->trace(m_syncHelper);
     WebSocketChannelClient::trace(visitor);
 }

 Bridge::Bridge(ThreadableWebSocketChannelClientWrapper* workerClientWrapper, WorkerGlobalScope& workerGlobalScope)
     : m_workerClientWrapper(workerClientWrapper)
     , m_workerGlobalScope(workerGlobalScope)
     , m_loaderProxy(m_workerGlobalScope->thread()->workerLoaderProxy())
     , m_syncHelper(ThreadableWebSocketChannelSyncHelper::create(adoptPtr(Platform::current()->createWaitableEvent())))
     , m_peer(Peer::create(m_workerClientWrapper, m_loaderProxy, m_syncHelper))
 {
     ASSERT(m_workerClientWrapper.get());
 }

 Bridge::~Bridge()
 {
     ASSERT(!m_peer);
 }

 void Bridge::initialize(const String& sourceURL, unsigned lineNumber)
 {
     // In order to assure all temporary objects to be destroyed before
     // posting the task, we separate task creation and posting.
     // In other words, it is dangerous to have a complicated expression
     // as a waitForMethodCompletion argument.
     OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&Peer::initialize, AllowCrossThreadAccess(m_peer.get()), sourceURL, lineNumber);
     if (!waitForMethodCompletion(task.release())) {
         // The worker thread has been signalled to shutdown before method completion.
         disconnect();
     }
 }

 bool Bridge::connect(const KURL& url, const String& protocol)
 {
     if (!m_peer)
         return false;

     if (!waitForMethodCompletion(createCrossThreadTask(&Peer::connect, m_peer.get(), url, protocol)))
         return false;

     return m_syncHelper->connectRequestResult();
 }

 void Bridge::send(const String& message)
 {
     ASSERT(m_peer);
     m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::send, m_peer.get(), message));
 }

 void Bridge::send(const ArrayBuffer& binaryData, unsigned byteOffset, unsigned byteLength)
 {
     ASSERT(m_peer);
     // ArrayBuffer isn't thread-safe, hence the content of ArrayBuffer is copied into Vector<char>.
     OwnPtr<Vector<char> > data = adoptPtr(new Vector<char>(byteLength));
     if (binaryData.byteLength())
         memcpy(data->data(), static_cast<const char*>(binaryData.data()) + byteOffset, byteLength);

     m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::sendArrayBuffer, m_peer.get(), data.release()));
 }

 void Bridge::send(PassRefPtr<BlobDataHandle> data)
 {
     ASSERT(m_peer);
     m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::sendBlob, m_peer.get(), data));
 }

 void Bridge::close(int code, const String& reason)
 {
     ASSERT(m_peer);
     m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::close, m_peer.get(), code, reason));
 }

 void Bridge::fail(const String& reason, MessageLevel level, const String& sourceURL, unsigned lineNumber)
 {
     ASSERT(m_peer);
     m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::fail, m_peer.get(), reason, level, sourceURL, lineNumber));
 }

 void Bridge::disconnect()
 {
     if (!m_peer)
         return;

     m_workerClientWrapper->clearClient();
     waitForMethodCompletion(createCrossThreadTask(&Peer::disconnect, m_peer.get()));
     // Here |m_peer| is detached from the main thread and we can delete it.

     m_peer = nullptr;
     m_syncHelper = nullptr;
     // We won't use this any more.
     m_workerGlobalScope.clear();
 }

 // Caller of this function should hold a reference to the bridge, because this function may call WebSocket::didClose() in the end,
 // which causes the bridge to get disconnected from the WebSocket and deleted if there is no other reference.
 bool Bridge::waitForMethodCompletion(PassOwnPtr<ExecutionContextTask> task)
 {
     ASSERT(m_workerGlobalScope);
     ASSERT(m_syncHelper);

     m_loaderProxy.postTaskToLoader(task);

     // We wait for the syncHelper event even if a shutdown event is fired.
     // See https://codereview.chromium.org/267323004/#msg43 for why we need to wait this.
     ThreadState::SafePointScope scope(ThreadState::HeapPointersOnStack);
     m_syncHelper->wait();
     // This is checking whether a shutdown event is fired or not.
     return !m_workerGlobalScope->thread()->terminated();
 }

 void Bridge::trace(Visitor* visitor)
 {
     visitor->trace(m_workerClientWrapper);
     visitor->trace(m_workerGlobalScope);
     visitor->trace(m_syncHelper);
     visitor->trace(m_peer);
 }

 } // namespace blink
	/*
	* Copyright (C) 2011, 2012 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:
	*
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following disclaimer
	* in the documentation and/or other materials provided with the
	* distribution.
	* * Neither the name of Google Inc. nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"

	#include "modules/websockets/WorkerThreadableWebSocketChannel.h"

	#include "bindings/core/v8/ScriptCallStackFactory.h"
	#include "core/dom/CrossThreadTask.h"
	#include "core/dom/Document.h"
	#include "core/dom/ExecutionContext.h"
	#include "core/fileapi/Blob.h"
	#include "core/inspector/ScriptCallFrame.h"
	#include "core/inspector/ScriptCallStack.h"
	#include "core/workers/WorkerLoaderProxy.h"
	#include "core/workers/WorkerThread.h"
	#include "modules/websockets/MainThreadWebSocketChannel.h"
	#include "modules/websockets/NewWebSocketChannelImpl.h"
	#include "modules/websockets/ThreadableWebSocketChannelClientWrapper.h"
	#include "platform/RuntimeEnabledFeatures.h"
	#include "public/platform/Platform.h"
	#include "public/platform/WebWaitableEvent.h"
	#include "wtf/ArrayBuffer.h"
	#include "wtf/Assertions.h"
	#include "wtf/Functional.h"
	#include "wtf/MainThread.h"

	namespace blink {

	typedef WorkerThreadableWebSocketChannel::Bridge Bridge;
	typedef WorkerThreadableWebSocketChannel::Peer Peer;

	// Created and destroyed on the worker thread. All setters of this class are
	// called on the main thread, while all getters are called on the worker
	// thread. signalWorkerThread() must be called before any getters are called.
	class ThreadableWebSocketChannelSyncHelper : public GarbageCollectedFinalized<ThreadableWebSocketChannelSyncHelper> {
	public:
	static ThreadableWebSocketChannelSyncHelper* create(PassOwnPtr<WebWaitableEvent> event)
	{
	return new ThreadableWebSocketChannelSyncHelper(event);
	}

	~ThreadableWebSocketChannelSyncHelper()
	{
	}

	// All setters are called on the main thread.
	void setConnectRequestResult(bool connectRequestResult)
	{
	m_connectRequestResult = connectRequestResult;
	}

	// All getter are called on the worker thread.
	bool connectRequestResult() const
	{
	return m_connectRequestResult;
	}

	// This should be called after all setters are called and before any
	// getters are called.
	void signalWorkerThread()
	{
	m_event->signal();
	}
	void wait()
	{
	m_event->wait();
	}

	void trace(Visitor* visitor) { }

	private:
	explicit ThreadableWebSocketChannelSyncHelper(PassOwnPtr<WebWaitableEvent> event)
	: m_event(event)
	, m_connectRequestResult(false)
	{
	}

	OwnPtr<WebWaitableEvent> m_event;
	bool m_connectRequestResult;
	};

	WorkerThreadableWebSocketChannel::WorkerThreadableWebSocketChannel(WorkerGlobalScope& workerGlobalScope, WebSocketChannelClient* client, const String& sourceURL, unsigned lineNumber)
	: m_workerClientWrapper(ThreadableWebSocketChannelClientWrapper::create(client))
	, m_bridge(Bridge::create(m_workerClientWrapper, workerGlobalScope))
	, m_sourceURLAtConnection(sourceURL)
	, m_lineNumberAtConnection(lineNumber)
	{
	ASSERT(m_workerClientWrapper.get());
	m_bridge->initialize(sourceURL, lineNumber);
	}

	WorkerThreadableWebSocketChannel::~WorkerThreadableWebSocketChannel()
	{
	ASSERT(!m_bridge);
	}

	bool WorkerThreadableWebSocketChannel::connect(const KURL& url, const String& protocol)
	{
	ASSERT(m_bridge);
	return m_bridge->connect(url, protocol);
	}

	void WorkerThreadableWebSocketChannel::send(const String& message)
	{
	ASSERT(m_bridge);
	m_bridge->send(message);
	}

	void WorkerThreadableWebSocketChannel::send(const ArrayBuffer& binaryData, unsigned byteOffset, unsigned byteLength)
	{
	ASSERT(m_bridge);
	m_bridge->send(binaryData, byteOffset, byteLength);
	}

	void WorkerThreadableWebSocketChannel::send(PassRefPtr<BlobDataHandle> blobData)
	{
	ASSERT(m_bridge);
	m_bridge->send(blobData);
	}

	void WorkerThreadableWebSocketChannel::close(int code, const String& reason)
	{
	ASSERT(m_bridge);
	m_bridge->close(code, reason);
	}

	void WorkerThreadableWebSocketChannel::fail(const String& reason, MessageLevel level, const String& sourceURL, unsigned lineNumber)
	{
	if (!m_bridge)
	return;

	RefPtrWillBeRawPtr<ScriptCallStack> callStack = createScriptCallStack(1, true);
	if (callStack && callStack->size()) {
	// In order to emulate the ConsoleMessage behavior,
	// we should ignore the specified url and line number if
	// we can get the JavaScript context.
	m_bridge->fail(reason, level, callStack->at(0).sourceURL(), callStack->at(0).lineNumber());
	} else if (sourceURL.isEmpty() && !lineNumber) {
	// No information is specified by the caller - use the url
	// and the line number at the connection.
	m_bridge->fail(reason, level, m_sourceURLAtConnection, m_lineNumberAtConnection);
	} else {
	// Use the specified information.
	m_bridge->fail(reason, level, sourceURL, lineNumber);
	}
	}

	void WorkerThreadableWebSocketChannel::disconnect()
	{
	m_bridge->disconnect();
	m_bridge.clear();
	}

	void WorkerThreadableWebSocketChannel::trace(Visitor* visitor)
	{
	visitor->trace(m_bridge);
	visitor->trace(m_workerClientWrapper);
	WebSocketChannel::trace(visitor);
	}

	Peer::Peer(ThreadableWebSocketChannelClientWrapper* clientWrapper, WorkerLoaderProxy& loaderProxy, ThreadableWebSocketChannelSyncHelper* syncHelper)
	: m_workerClientWrapper(clientWrapper)
	, m_loaderProxy(loaderProxy)
	, m_mainWebSocketChannel(nullptr)
	, m_syncHelper(syncHelper)
	{
	ASSERT(!isMainThread());
	}

	Peer::~Peer()
	{
	ASSERT(!isMainThread());
	}

	Peer* Peer::create(ThreadableWebSocketChannelClientWrapper* clientWrapper, WorkerLoaderProxy& loaderProxy, ThreadableWebSocketChannelSyncHelper* syncHelper)
	{
	return new Peer(clientWrapper, loaderProxy, syncHelper);
	}

	void Peer::initializeInternal(ExecutionContext* context, const String& sourceURL, unsigned lineNumber)
	{
	ASSERT(isMainThread());
	Document* document = toDocument(context);
	if (RuntimeEnabledFeatures::experimentalWebSocketEnabled()) {
	m_mainWebSocketChannel = NewWebSocketChannelImpl::create(document, this, sourceURL, lineNumber);
	} else {
	m_mainWebSocketChannel = MainThreadWebSocketChannel::create(document, this, sourceURL, lineNumber);
	}
	m_syncHelper->signalWorkerThread();
	}

	void Peer::connect(const KURL& url, const String& protocol)
	{
	ASSERT(isMainThread());
	ASSERT(m_syncHelper);
	if (!m_mainWebSocketChannel) {
	m_syncHelper->setConnectRequestResult(false);
	} else {
	bool connectRequestResult = m_mainWebSocketChannel->connect(url, protocol);
	m_syncHelper->setConnectRequestResult(connectRequestResult);
	}
	m_syncHelper->signalWorkerThread();
	}

	void Peer::send(const String& message)
	{
	ASSERT(isMainThread());
	if (m_mainWebSocketChannel)
	m_mainWebSocketChannel->send(message);
	}

	void Peer::sendArrayBuffer(PassOwnPtr<Vector<char> > data)
	{
	ASSERT(isMainThread());
	if (m_mainWebSocketChannel)
	m_mainWebSocketChannel->send(data);
	}

	void Peer::sendBlob(PassRefPtr<BlobDataHandle> blobData)
	{
	ASSERT(isMainThread());
	if (m_mainWebSocketChannel)
	m_mainWebSocketChannel->send(blobData);
	}

	void Peer::close(int code, const String& reason)
	{
	ASSERT(isMainThread());
	ASSERT(m_syncHelper);
	if (!m_mainWebSocketChannel)
	return;
	m_mainWebSocketChannel->close(code, reason);
	}

	void Peer::fail(const String& reason, MessageLevel level, const String& sourceURL, unsigned lineNumber)
	{
	ASSERT(isMainThread());
	ASSERT(m_syncHelper);
	if (!m_mainWebSocketChannel)
	return;
	m_mainWebSocketChannel->fail(reason, level, sourceURL, lineNumber);
	}

	void Peer::disconnect()
	{
	ASSERT(isMainThread());
	ASSERT(m_syncHelper);
	if (m_mainWebSocketChannel) {
	m_mainWebSocketChannel->disconnect();
	m_mainWebSocketChannel = nullptr;
	}
	m_syncHelper->signalWorkerThread();
	}

	static void workerGlobalScopeDidConnect(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, const String& subprotocol, const String& extensions)
	{
	ASSERT_UNUSED(context, context->isWorkerGlobalScope());
	workerClientWrapper->didConnect(subprotocol, extensions);
	}

	void Peer::didConnect(const String& subprotocol, const String& extensions)
	{
	ASSERT(isMainThread());
	// It is important to seprate task creation from posting
	// the task. See the above comment.
	OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidConnect, m_workerClientWrapper, subprotocol, extensions);
	m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
	}

	static void workerGlobalScopeDidReceiveMessage(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, const String& message)
	{
	ASSERT_UNUSED(context, context->isWorkerGlobalScope());
	workerClientWrapper->didReceiveMessage(message);
	}

	void Peer::didReceiveMessage(const String& message)
	{
	ASSERT(isMainThread());
	// It is important to seprate task creation from posting
	// the task. See the above comment.
	OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidReceiveMessage, m_workerClientWrapper, message);
	m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
	}

	static void workerGlobalScopeDidReceiveBinaryData(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, PassOwnPtr<Vector<char> > binaryData)
	{
	ASSERT_UNUSED(context, context->isWorkerGlobalScope());
	workerClientWrapper->didReceiveBinaryData(binaryData);
	}

	void Peer::didReceiveBinaryData(PassOwnPtr<Vector<char> > binaryData)
	{
	ASSERT(isMainThread());
	// It is important to seprate task creation from posting
	// the task. See the above comment.
	OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidReceiveBinaryData, m_workerClientWrapper, binaryData);
	m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
	}

	static void workerGlobalScopeDidConsumeBufferedAmount(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, unsigned long consumed)
	{
	ASSERT_UNUSED(context, context->isWorkerGlobalScope());
	workerClientWrapper->didConsumeBufferedAmount(consumed);
	}

	void Peer::didConsumeBufferedAmount(unsigned long consumed)
	{
	ASSERT(isMainThread());
	// It is important to seprate task creation from posting
	// the task. See the above comment.
	OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidConsumeBufferedAmount, m_workerClientWrapper, consumed);
	m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
	}

	static void workerGlobalScopeDidStartClosingHandshake(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper)
	{
	ASSERT_UNUSED(context, context->isWorkerGlobalScope());
	workerClientWrapper->didStartClosingHandshake();
	}

	void Peer::didStartClosingHandshake()
	{
	ASSERT(isMainThread());
	// It is important to seprate task creation from posting
	// the task. See the above comment.
	OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidStartClosingHandshake, m_workerClientWrapper);
	m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
	}

	static void workerGlobalScopeDidClose(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper, WebSocketChannelClient::ClosingHandshakeCompletionStatus closingHandshakeCompletion, unsigned short code, const String& reason)
	{
	ASSERT_UNUSED(context, context->isWorkerGlobalScope());
	workerClientWrapper->didClose(closingHandshakeCompletion, code, reason);
	}

	void Peer::didClose(ClosingHandshakeCompletionStatus closingHandshakeCompletion, unsigned short code, const String& reason)
	{
	ASSERT(isMainThread());
	if (m_mainWebSocketChannel) {
	m_mainWebSocketChannel->disconnect();
	m_mainWebSocketChannel = nullptr;
	}
	// It is important to seprate task creation from posting
	// the task. See the above comment.
	OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidClose, m_workerClientWrapper, closingHandshakeCompletion, code, reason);
	m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
	}

	static void workerGlobalScopeDidReceiveMessageError(ExecutionContext* context, ThreadableWebSocketChannelClientWrapper* workerClientWrapper)
	{
	ASSERT_UNUSED(context, context->isWorkerGlobalScope());
	workerClientWrapper->didReceiveMessageError();
	}

	void Peer::didReceiveMessageError()
	{
	ASSERT(isMainThread());
	// It is important to seprate task creation from posting
	// the task. See the above comment.
	OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&workerGlobalScopeDidReceiveMessageError, m_workerClientWrapper);
	m_loaderProxy.postTaskToWorkerGlobalScope(task.release());
	}

	void Peer::trace(Visitor* visitor)
	{
	visitor->trace(m_workerClientWrapper);
	visitor->trace(m_mainWebSocketChannel);
	visitor->trace(m_syncHelper);
	WebSocketChannelClient::trace(visitor);
	}

	Bridge::Bridge(ThreadableWebSocketChannelClientWrapper* workerClientWrapper, WorkerGlobalScope& workerGlobalScope)
	: m_workerClientWrapper(workerClientWrapper)
	, m_workerGlobalScope(workerGlobalScope)
	, m_loaderProxy(m_workerGlobalScope->thread()->workerLoaderProxy())
	, m_syncHelper(ThreadableWebSocketChannelSyncHelper::create(adoptPtr(Platform::current()->createWaitableEvent())))
	, m_peer(Peer::create(m_workerClientWrapper, m_loaderProxy, m_syncHelper))
	{
	ASSERT(m_workerClientWrapper.get());
	}

	Bridge::~Bridge()
	{
	ASSERT(!m_peer);
	}

	void Bridge::initialize(const String& sourceURL, unsigned lineNumber)
	{
	// In order to assure all temporary objects to be destroyed before
	// posting the task, we separate task creation and posting.
	// In other words, it is dangerous to have a complicated expression
	// as a waitForMethodCompletion argument.
	OwnPtr<ExecutionContextTask> task = createCrossThreadTask(&Peer::initialize, AllowCrossThreadAccess(m_peer.get()), sourceURL, lineNumber);
	if (!waitForMethodCompletion(task.release())) {
	// The worker thread has been signalled to shutdown before method completion.
	disconnect();
	}
	}

	bool Bridge::connect(const KURL& url, const String& protocol)
	{
	if (!m_peer)
	return false;

	if (!waitForMethodCompletion(createCrossThreadTask(&Peer::connect, m_peer.get(), url, protocol)))
	return false;

	return m_syncHelper->connectRequestResult();
	}

	void Bridge::send(const String& message)
	{
	ASSERT(m_peer);
	m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::send, m_peer.get(), message));
	}

	void Bridge::send(const ArrayBuffer& binaryData, unsigned byteOffset, unsigned byteLength)
	{
	ASSERT(m_peer);
	// ArrayBuffer isn't thread-safe, hence the content of ArrayBuffer is copied into Vector<char>.
	OwnPtr<Vector<char> > data = adoptPtr(new Vector<char>(byteLength));
	if (binaryData.byteLength())
	memcpy(data->data(), static_cast<const char*>(binaryData.data()) + byteOffset, byteLength);

	m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::sendArrayBuffer, m_peer.get(), data.release()));
	}

	void Bridge::send(PassRefPtr<BlobDataHandle> data)
	{
	ASSERT(m_peer);
	m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::sendBlob, m_peer.get(), data));
	}

	void Bridge::close(int code, const String& reason)
	{
	ASSERT(m_peer);
	m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::close, m_peer.get(), code, reason));
	}

	void Bridge::fail(const String& reason, MessageLevel level, const String& sourceURL, unsigned lineNumber)
	{
	ASSERT(m_peer);
	m_loaderProxy.postTaskToLoader(createCrossThreadTask(&Peer::fail, m_peer.get(), reason, level, sourceURL, lineNumber));
	}

	void Bridge::disconnect()
	{
	if (!m_peer)
	return;

	m_workerClientWrapper->clearClient();
	waitForMethodCompletion(createCrossThreadTask(&Peer::disconnect, m_peer.get()));
	// Here \|m_peer\| is detached from the main thread and we can delete it.

	m_peer = nullptr;
	m_syncHelper = nullptr;
	// We won't use this any more.
	m_workerGlobalScope.clear();
	}

	// Caller of this function should hold a reference to the bridge, because this function may call WebSocket::didClose() in the end,
	// which causes the bridge to get disconnected from the WebSocket and deleted if there is no other reference.
	bool Bridge::waitForMethodCompletion(PassOwnPtr<ExecutionContextTask> task)
	{
	ASSERT(m_workerGlobalScope);
	ASSERT(m_syncHelper);

	m_loaderProxy.postTaskToLoader(task);

	// We wait for the syncHelper event even if a shutdown event is fired.
	// See https://codereview.chromium.org/267323004/#msg43 for why we need to wait this.
	ThreadState::SafePointScope scope(ThreadState::HeapPointersOnStack);
	m_syncHelper->wait();
	// This is checking whether a shutdown event is fired or not.
	return !m_workerGlobalScope->thread()->terminated();
	}

	void Bridge::trace(Visitor* visitor)
	{
	visitor->trace(m_workerClientWrapper);
	visitor->trace(m_workerGlobalScope);
	visitor->trace(m_syncHelper);
	visitor->trace(m_peer);
	}

	} // namespace blink