Source/core/html/parser/BackgroundHTMLParser.cpp - chromium/blink - Git at Google

 /*
  * Copyright (C) 2013 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
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``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 GOOGLE INC. 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 "core/html/parser/BackgroundHTMLParser.h"

 #include "core/HTMLNames.h"
 #include "core/html/parser/HTMLDocumentParser.h"
 #include "core/html/parser/TextResourceDecoder.h"
 #include "core/html/parser/XSSAuditor.h"
 #include "platform/Task.h"
 #include "platform/ThreadSafeFunctional.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebScheduler.h"
 #include "wtf/text/TextPosition.h"

 namespace blink {

 // On a network with high latency and high bandwidth, using a device
 // with a fast CPU, we could end up speculatively tokenizing
 // the whole document, well ahead of when the main-thread actually needs it.
 // This is a waste of memory (and potentially time if the speculation fails).
 // So we limit our outstanding tokens arbitrarily to 10,000.
 // Our maximal memory spent speculating will be approximately:
 // (defaultOutstandingTokenLimit + defaultPendingTokenLimit) *
 //     sizeof(CompactToken)
 // We use a separate low and high water mark to avoid constantly topping
 // off the main thread's token buffer.
 // At time of writing, this is (10000 + 1000) * 28 bytes = ~308kb of memory.
 // These numbers have not been tuned.
 static const size_t defaultOutstandingTokenLimit = 10000;

 // We limit our chucks to 1000 tokens, to make sure the main
 // thread is never waiting on the parser thread for tokens.
 // This was tuned in https://bugs.webkit.org/show_bug.cgi?id=110408.
 static const size_t defaultPendingTokenLimit = 1000;

 using namespace HTMLNames;

 #if ENABLE(ASSERT)

 static void checkThatTokensAreSafeToSendToAnotherThread(const CompactHTMLTokenStream* tokens)
 {
     for (size_t i = 0; i < tokens->size(); ++i)
         ASSERT(tokens->at(i).isSafeToSendToAnotherThread());
 }

 static void checkThatPreloadsAreSafeToSendToAnotherThread(const PreloadRequestStream& preloads)
 {
     for (size_t i = 0; i < preloads.size(); ++i)
         ASSERT(preloads[i]->isSafeToSendToAnotherThread());
 }

 static void checkThatXSSInfosAreSafeToSendToAnotherThread(const XSSInfoStream& infos)
 {
     for (size_t i = 0; i < infos.size(); ++i)
         ASSERT(infos[i]->isSafeToSendToAnotherThread());
 }

 #endif

 void BackgroundHTMLParser::start(PassRefPtr<WeakReference<BackgroundHTMLParser>> reference, PassOwnPtr<Configuration> config, WebScheduler* scheduler)
 {
     new BackgroundHTMLParser(reference, config, scheduler);
     // Caller must free by calling stop().
 }

 BackgroundHTMLParser::Configuration::Configuration()
     : outstandingTokenLimit(defaultOutstandingTokenLimit)
     , pendingTokenLimit(defaultPendingTokenLimit)
 {
 }

 BackgroundHTMLParser::BackgroundHTMLParser(PassRefPtr<WeakReference<BackgroundHTMLParser>> reference, PassOwnPtr<Configuration> config, WebScheduler* scheduler)
     : m_weakFactory(reference, this)
     , m_token(adoptPtr(new HTMLToken))
     , m_tokenizer(HTMLTokenizer::create(config->options))
     , m_treeBuilderSimulator(config->options)
     , m_options(config->options)
     , m_outstandingTokenLimit(config->outstandingTokenLimit)
     , m_parser(config->parser)
     , m_pendingTokens(adoptPtr(new CompactHTMLTokenStream))
     , m_pendingTokenLimit(config->pendingTokenLimit)
     , m_xssAuditor(config->xssAuditor.release())
     , m_preloadScanner(config->preloadScanner.release())
     , m_decoder(config->decoder.release())
     , m_scheduler(scheduler)
     , m_startingScript(false)
 {
     ASSERT(m_outstandingTokenLimit > 0);
     ASSERT(m_pendingTokenLimit > 0);
     ASSERT(m_outstandingTokenLimit >= m_pendingTokenLimit);
 }

 BackgroundHTMLParser::~BackgroundHTMLParser()
 {
 }

 void BackgroundHTMLParser::appendRawBytesFromParserThread(const char* data, int dataLength)
 {
     ASSERT(m_decoder);
     updateDocument(m_decoder->decode(data, dataLength));
 }

 void BackgroundHTMLParser::appendRawBytesFromMainThread(PassOwnPtr<Vector<char>> buffer)
 {
     ASSERT(m_decoder);
     updateDocument(m_decoder->decode(buffer->data(), buffer->size()));
 }

 void BackgroundHTMLParser::appendDecodedBytes(const String& input)
 {
     ASSERT(!m_input.current().isClosed());
     m_input.append(input);
     pumpTokenizer();
 }

 void BackgroundHTMLParser::setDecoder(PassOwnPtr<TextResourceDecoder> decoder)
 {
     ASSERT(decoder);
     m_decoder = decoder;
 }

 void BackgroundHTMLParser::flush()
 {
     ASSERT(m_decoder);
     updateDocument(m_decoder->flush());
 }

 void BackgroundHTMLParser::updateDocument(const String& decodedData)
 {
     DocumentEncodingData encodingData(*m_decoder.get());

     if (encodingData != m_lastSeenEncodingData) {
         m_lastSeenEncodingData = encodingData;

         m_xssAuditor->setEncoding(encodingData.encoding());
         m_scheduler->loadingTaskRunner()->postTask(
             FROM_HERE,
             threadSafeBind(&HTMLDocumentParser::didReceiveEncodingDataFromBackgroundParser, AllowCrossThreadAccess(m_parser), encodingData));
     }

     if (decodedData.isEmpty())
         return;

     appendDecodedBytes(decodedData);
 }

 void BackgroundHTMLParser::resumeFrom(PassOwnPtr<Checkpoint> checkpoint)
 {
     m_parser = checkpoint->parser;
     m_token = checkpoint->token.release();
     m_tokenizer = checkpoint->tokenizer.release();
     m_treeBuilderSimulator.setState(checkpoint->treeBuilderState);
     m_input.rewindTo(checkpoint->inputCheckpoint, checkpoint->unparsedInput);
     m_preloadScanner->rewindTo(checkpoint->preloadScannerCheckpoint);
     m_startingScript = false;
     pumpTokenizer();
 }

 void BackgroundHTMLParser::startedChunkWithCheckpoint(HTMLInputCheckpoint inputCheckpoint)
 {
     // Note, we should not have to worry about the index being invalid
     // as messages from the main thread will be processed in FIFO order.
     m_input.invalidateCheckpointsBefore(inputCheckpoint);
     pumpTokenizer();
 }

 void BackgroundHTMLParser::finish()
 {
     markEndOfFile();
     pumpTokenizer();
 }

 void BackgroundHTMLParser::stop()
 {
     delete this;
 }

 void BackgroundHTMLParser::forcePlaintextForTextDocument()
 {
     // This is only used by the TextDocumentParser (a subclass of HTMLDocumentParser)
     // to force us into the PLAINTEXT state w/o using a <plaintext> tag.
     // The TextDocumentParser uses a <pre> tag for historical/compatibility reasons.
     m_tokenizer->setState(HTMLTokenizer::PLAINTEXTState);
 }

 void BackgroundHTMLParser::markEndOfFile()
 {
     ASSERT(!m_input.current().isClosed());
     m_input.append(String(&kEndOfFileMarker, 1));
     m_input.close();
 }

 void BackgroundHTMLParser::pumpTokenizer()
 {
     HTMLTreeBuilderSimulator::SimulatedToken simulatedToken = HTMLTreeBuilderSimulator::OtherToken;

     // No need to start speculating until the main thread has almost caught up.
     if (m_input.totalCheckpointTokenCount() > m_outstandingTokenLimit)
         return;

     while (true) {
         if (m_xssAuditor->isEnabled())
             m_sourceTracker.start(m_input.current(), m_tokenizer.get(), *m_token);

         if (!m_tokenizer->nextToken(m_input.current(), *m_token)) {
             // We've reached the end of our current input.
             sendTokensToMainThread();
             break;
         }

         if (m_xssAuditor->isEnabled())
             m_sourceTracker.end(m_input.current(), m_tokenizer.get(), *m_token);

         {
             TextPosition position = TextPosition(m_input.current().currentLine(), m_input.current().currentColumn());

             if (OwnPtr<XSSInfo> xssInfo = m_xssAuditor->filterToken(FilterTokenRequest(*m_token, m_sourceTracker, m_tokenizer->shouldAllowCDATA()))) {
                 xssInfo->m_textPosition = position;
                 m_pendingXSSInfos.append(xssInfo.release());
             }

             CompactHTMLToken token(m_token.get(), position);

             m_preloadScanner->scan(token, m_input.current(), m_pendingPreloads);
             simulatedToken = m_treeBuilderSimulator.simulate(token, m_tokenizer.get());

             // Break chunks before a script tag is inserted and flag the chunk as starting a script
             // so the main parser can decide if it should yield before processing the chunk.
             if (simulatedToken == HTMLTreeBuilderSimulator::ScriptStart) {
                 sendTokensToMainThread();
                 m_startingScript = true;
             }

             m_pendingTokens->append(token);
         }

         m_token->clear();

         if (simulatedToken == HTMLTreeBuilderSimulator::ScriptEnd || m_pendingTokens->size() >= m_pendingTokenLimit) {
             sendTokensToMainThread();
             // If we're far ahead of the main thread, yield for a bit to avoid consuming too much memory.
             if (m_input.totalCheckpointTokenCount() > m_outstandingTokenLimit)
                 break;
         }
     }
 }

 void BackgroundHTMLParser::sendTokensToMainThread()
 {
     if (m_pendingTokens->isEmpty())
         return;

 #if ENABLE(ASSERT)
     checkThatTokensAreSafeToSendToAnotherThread(m_pendingTokens.get());
     checkThatPreloadsAreSafeToSendToAnotherThread(m_pendingPreloads);
     checkThatXSSInfosAreSafeToSendToAnotherThread(m_pendingXSSInfos);
 #endif

     OwnPtr<HTMLDocumentParser::ParsedChunk> chunk = adoptPtr(new HTMLDocumentParser::ParsedChunk);
     chunk->preloads.swap(m_pendingPreloads);
     chunk->xssInfos.swap(m_pendingXSSInfos);
     chunk->tokenizerState = m_tokenizer->state();
     chunk->treeBuilderState = m_treeBuilderSimulator.state();
     chunk->inputCheckpoint = m_input.createCheckpoint(m_pendingTokens->size());
     chunk->preloadScannerCheckpoint = m_preloadScanner->createCheckpoint();
     chunk->tokens = m_pendingTokens.release();
     chunk->startingScript = m_startingScript;
     m_startingScript = false;

     m_scheduler->loadingTaskRunner()->postTask(
         FROM_HERE,
         new Task(threadSafeBind(&HTMLDocumentParser::didReceiveParsedChunkFromBackgroundParser, AllowCrossThreadAccess(m_parser), chunk.release())));

     m_pendingTokens = adoptPtr(new CompactHTMLTokenStream);
 }

 }
	/*
	* Copyright (C) 2013 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
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``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 GOOGLE INC. 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 "core/html/parser/BackgroundHTMLParser.h"

	#include "core/HTMLNames.h"
	#include "core/html/parser/HTMLDocumentParser.h"
	#include "core/html/parser/TextResourceDecoder.h"
	#include "core/html/parser/XSSAuditor.h"
	#include "platform/Task.h"
	#include "platform/ThreadSafeFunctional.h"
	#include "public/platform/Platform.h"
	#include "public/platform/WebScheduler.h"
	#include "wtf/text/TextPosition.h"

	namespace blink {

	// On a network with high latency and high bandwidth, using a device
	// with a fast CPU, we could end up speculatively tokenizing
	// the whole document, well ahead of when the main-thread actually needs it.
	// This is a waste of memory (and potentially time if the speculation fails).
	// So we limit our outstanding tokens arbitrarily to 10,000.
	// Our maximal memory spent speculating will be approximately:
	// (defaultOutstandingTokenLimit + defaultPendingTokenLimit) *
	// sizeof(CompactToken)
	// We use a separate low and high water mark to avoid constantly topping
	// off the main thread's token buffer.
	// At time of writing, this is (10000 + 1000) * 28 bytes = ~308kb of memory.
	// These numbers have not been tuned.
	static const size_t defaultOutstandingTokenLimit = 10000;

	// We limit our chucks to 1000 tokens, to make sure the main
	// thread is never waiting on the parser thread for tokens.
	// This was tuned in https://bugs.webkit.org/show_bug.cgi?id=110408.
	static const size_t defaultPendingTokenLimit = 1000;

	using namespace HTMLNames;

	#if ENABLE(ASSERT)

	static void checkThatTokensAreSafeToSendToAnotherThread(const CompactHTMLTokenStream* tokens)
	{
	for (size_t i = 0; i < tokens->size(); ++i)
	ASSERT(tokens->at(i).isSafeToSendToAnotherThread());
	}

	static void checkThatPreloadsAreSafeToSendToAnotherThread(const PreloadRequestStream& preloads)
	{
	for (size_t i = 0; i < preloads.size(); ++i)
	ASSERT(preloads[i]->isSafeToSendToAnotherThread());
	}

	static void checkThatXSSInfosAreSafeToSendToAnotherThread(const XSSInfoStream& infos)
	{
	for (size_t i = 0; i < infos.size(); ++i)
	ASSERT(infos[i]->isSafeToSendToAnotherThread());
	}

	#endif

	void BackgroundHTMLParser::start(PassRefPtr<WeakReference<BackgroundHTMLParser>> reference, PassOwnPtr<Configuration> config, WebScheduler* scheduler)
	{
	new BackgroundHTMLParser(reference, config, scheduler);
	// Caller must free by calling stop().
	}

	BackgroundHTMLParser::Configuration::Configuration()
	: outstandingTokenLimit(defaultOutstandingTokenLimit)
	, pendingTokenLimit(defaultPendingTokenLimit)
	{
	}

	BackgroundHTMLParser::BackgroundHTMLParser(PassRefPtr<WeakReference<BackgroundHTMLParser>> reference, PassOwnPtr<Configuration> config, WebScheduler* scheduler)
	: m_weakFactory(reference, this)
	, m_token(adoptPtr(new HTMLToken))
	, m_tokenizer(HTMLTokenizer::create(config->options))
	, m_treeBuilderSimulator(config->options)
	, m_options(config->options)
	, m_outstandingTokenLimit(config->outstandingTokenLimit)
	, m_parser(config->parser)
	, m_pendingTokens(adoptPtr(new CompactHTMLTokenStream))
	, m_pendingTokenLimit(config->pendingTokenLimit)
	, m_xssAuditor(config->xssAuditor.release())
	, m_preloadScanner(config->preloadScanner.release())
	, m_decoder(config->decoder.release())
	, m_scheduler(scheduler)
	, m_startingScript(false)
	{
	ASSERT(m_outstandingTokenLimit > 0);
	ASSERT(m_pendingTokenLimit > 0);
	ASSERT(m_outstandingTokenLimit >= m_pendingTokenLimit);
	}

	BackgroundHTMLParser::~BackgroundHTMLParser()
	{
	}

	void BackgroundHTMLParser::appendRawBytesFromParserThread(const char* data, int dataLength)
	{
	ASSERT(m_decoder);
	updateDocument(m_decoder->decode(data, dataLength));
	}

	void BackgroundHTMLParser::appendRawBytesFromMainThread(PassOwnPtr<Vector<char>> buffer)
	{
	ASSERT(m_decoder);
	updateDocument(m_decoder->decode(buffer->data(), buffer->size()));
	}

	void BackgroundHTMLParser::appendDecodedBytes(const String& input)
	{
	ASSERT(!m_input.current().isClosed());
	m_input.append(input);
	pumpTokenizer();
	}

	void BackgroundHTMLParser::setDecoder(PassOwnPtr<TextResourceDecoder> decoder)
	{
	ASSERT(decoder);
	m_decoder = decoder;
	}

	void BackgroundHTMLParser::flush()
	{
	ASSERT(m_decoder);
	updateDocument(m_decoder->flush());
	}

	void BackgroundHTMLParser::updateDocument(const String& decodedData)
	{
	DocumentEncodingData encodingData(*m_decoder.get());

	if (encodingData != m_lastSeenEncodingData) {
	m_lastSeenEncodingData = encodingData;

	m_xssAuditor->setEncoding(encodingData.encoding());
	m_scheduler->loadingTaskRunner()->postTask(
	FROM_HERE,
	threadSafeBind(&HTMLDocumentParser::didReceiveEncodingDataFromBackgroundParser, AllowCrossThreadAccess(m_parser), encodingData));
	}

	if (decodedData.isEmpty())
	return;

	appendDecodedBytes(decodedData);
	}

	void BackgroundHTMLParser::resumeFrom(PassOwnPtr<Checkpoint> checkpoint)
	{
	m_parser = checkpoint->parser;
	m_token = checkpoint->token.release();
	m_tokenizer = checkpoint->tokenizer.release();
	m_treeBuilderSimulator.setState(checkpoint->treeBuilderState);
	m_input.rewindTo(checkpoint->inputCheckpoint, checkpoint->unparsedInput);
	m_preloadScanner->rewindTo(checkpoint->preloadScannerCheckpoint);
	m_startingScript = false;
	pumpTokenizer();
	}

	void BackgroundHTMLParser::startedChunkWithCheckpoint(HTMLInputCheckpoint inputCheckpoint)
	{
	// Note, we should not have to worry about the index being invalid
	// as messages from the main thread will be processed in FIFO order.
	m_input.invalidateCheckpointsBefore(inputCheckpoint);
	pumpTokenizer();
	}

	void BackgroundHTMLParser::finish()
	{
	markEndOfFile();
	pumpTokenizer();
	}

	void BackgroundHTMLParser::stop()
	{
	delete this;
	}

	void BackgroundHTMLParser::forcePlaintextForTextDocument()
	{
	// This is only used by the TextDocumentParser (a subclass of HTMLDocumentParser)
	// to force us into the PLAINTEXT state w/o using a <plaintext> tag.
	// The TextDocumentParser uses a <pre> tag for historical/compatibility reasons.
	m_tokenizer->setState(HTMLTokenizer::PLAINTEXTState);
	}

	void BackgroundHTMLParser::markEndOfFile()
	{
	ASSERT(!m_input.current().isClosed());
	m_input.append(String(&kEndOfFileMarker, 1));
	m_input.close();
	}

	void BackgroundHTMLParser::pumpTokenizer()
	{
	HTMLTreeBuilderSimulator::SimulatedToken simulatedToken = HTMLTreeBuilderSimulator::OtherToken;

	// No need to start speculating until the main thread has almost caught up.
	if (m_input.totalCheckpointTokenCount() > m_outstandingTokenLimit)
	return;

	while (true) {
	if (m_xssAuditor->isEnabled())
	m_sourceTracker.start(m_input.current(), m_tokenizer.get(), *m_token);

	if (!m_tokenizer->nextToken(m_input.current(), *m_token)) {
	// We've reached the end of our current input.
	sendTokensToMainThread();
	break;
	}

	if (m_xssAuditor->isEnabled())
	m_sourceTracker.end(m_input.current(), m_tokenizer.get(), *m_token);

	{
	TextPosition position = TextPosition(m_input.current().currentLine(), m_input.current().currentColumn());

	if (OwnPtr<XSSInfo> xssInfo = m_xssAuditor->filterToken(FilterTokenRequest(*m_token, m_sourceTracker, m_tokenizer->shouldAllowCDATA()))) {
	xssInfo->m_textPosition = position;
	m_pendingXSSInfos.append(xssInfo.release());
	}

	CompactHTMLToken token(m_token.get(), position);

	m_preloadScanner->scan(token, m_input.current(), m_pendingPreloads);
	simulatedToken = m_treeBuilderSimulator.simulate(token, m_tokenizer.get());

	// Break chunks before a script tag is inserted and flag the chunk as starting a script
	// so the main parser can decide if it should yield before processing the chunk.
	if (simulatedToken == HTMLTreeBuilderSimulator::ScriptStart) {
	sendTokensToMainThread();
	m_startingScript = true;
	}

	m_pendingTokens->append(token);
	}

	m_token->clear();

	if (simulatedToken == HTMLTreeBuilderSimulator::ScriptEnd \|\| m_pendingTokens->size() >= m_pendingTokenLimit) {
	sendTokensToMainThread();
	// If we're far ahead of the main thread, yield for a bit to avoid consuming too much memory.
	if (m_input.totalCheckpointTokenCount() > m_outstandingTokenLimit)
	break;
	}
	}
	}

	void BackgroundHTMLParser::sendTokensToMainThread()
	{
	if (m_pendingTokens->isEmpty())
	return;

	#if ENABLE(ASSERT)
	checkThatTokensAreSafeToSendToAnotherThread(m_pendingTokens.get());
	checkThatPreloadsAreSafeToSendToAnotherThread(m_pendingPreloads);
	checkThatXSSInfosAreSafeToSendToAnotherThread(m_pendingXSSInfos);
	#endif

	OwnPtr<HTMLDocumentParser::ParsedChunk> chunk = adoptPtr(new HTMLDocumentParser::ParsedChunk);
	chunk->preloads.swap(m_pendingPreloads);
	chunk->xssInfos.swap(m_pendingXSSInfos);
	chunk->tokenizerState = m_tokenizer->state();
	chunk->treeBuilderState = m_treeBuilderSimulator.state();
	chunk->inputCheckpoint = m_input.createCheckpoint(m_pendingTokens->size());
	chunk->preloadScannerCheckpoint = m_preloadScanner->createCheckpoint();
	chunk->tokens = m_pendingTokens.release();
	chunk->startingScript = m_startingScript;
	m_startingScript = false;

	m_scheduler->loadingTaskRunner()->postTask(
	FROM_HERE,
	new Task(threadSafeBind(&HTMLDocumentParser::didReceiveParsedChunkFromBackgroundParser, AllowCrossThreadAccess(m_parser), chunk.release())));

	m_pendingTokens = adoptPtr(new CompactHTMLTokenStream);
	}

	}