Turn DocumentParser::pinToMainThread into a cleaner api

Source/core/html/parser/HTMLDocumentParser.cpp

 /*
  * Copyright (C) 2010 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
@@ skipping 84 matching lines @@
         if (HTMLParserThread::shared())
             return &HTMLParserThread::shared()->platformThread();
 
         return nullptr;
     }
 
 private:
     WeakPtr<BackgroundHTMLParser> m_backgroundParser;
 };
 
-HTMLDocumentParser::HTMLDocumentParser(HTMLDocument& document, bool reportErrors)
+HTMLDocumentParser::HTMLDocumentParser(HTMLDocument& document, bool reportErrors, ParserSynchronizationPolicy backgroundParsingPolicy)
     : ScriptableDocumentParser(document)
     , m_options(&document)
-    , m_token(nullptr)
-    , m_tokenizer(nullptr)
+    , m_token(backgroundParsingPolicy == ForceSynchronousParsing ? adoptPtr(new HTMLToken) : nullptr)
+    , m_tokenizer(backgroundParsingPolicy == ForceSynchronousParsing ? HTMLTokenizer::create(m_options) : nullptr)
     , m_scriptRunner(HTMLScriptRunner::create(&document, this))
     , m_treeBuilder(HTMLTreeBuilder::create(this, &document, parserContentPolicy(), reportErrors, m_options))
     , m_parserScheduler(HTMLParserScheduler::create(this))
     , m_xssAuditorDelegate(&document)
     , m_weakFactory(this)
     , m_preloader(HTMLResourcePreloader::create(document))
-    , m_isPinnedToMainThread(false)
+    , m_shouldUseThreading(backgroundParsingPolicy == AllowAsynchronousParsing)
     , m_endWasDelayed(false)
     , m_haveBackgroundParser(false)
     , m_tasksWereSuspended(false)
     , m_pumpSessionNestingLevel(0)
     , m_pumpSpeculationsSessionNestingLevel(0)
 {
     ASSERT(shouldUseThreading() || (m_token && m_tokenizer));
 }
 
 // FIXME: Member variables should be grouped into self-initializing structs to
 // minimize code duplication between these constructors.
 HTMLDocumentParser::HTMLDocumentParser(DocumentFragment* fragment, Element* contextElement, ParserContentPolicy parserContentPolicy)
     : ScriptableDocumentParser(fragment->document(), parserContentPolicy)
     , m_options(&fragment->document())
     , m_token(adoptPtr(new HTMLToken))
     , m_tokenizer(HTMLTokenizer::create(m_options))
     , m_treeBuilder(HTMLTreeBuilder::create(this, fragment, contextElement, this->parserContentPolicy(), m_options))
     , m_xssAuditorDelegate(&fragment->document())
     , m_weakFactory(this)
-    , m_isPinnedToMainThread(true)
+    , m_shouldUseThreading(false)
     , m_endWasDelayed(false)
     , m_haveBackgroundParser(false)
     , m_tasksWereSuspended(false)
     , m_pumpSessionNestingLevel(0)
     , m_pumpSpeculationsSessionNestingLevel(0)
 {
-    ASSERT(!shouldUseThreading());
     bool reportErrors = false; // For now document fragment parsing never reports errors.
     m_tokenizer->setState(tokenizerStateForContextElement(contextElement, reportErrors, m_options));
     m_xssAuditor.initForFragment();
 }
 
 HTMLDocumentParser::~HTMLDocumentParser()
 {
 #if ENABLE(OILPAN)
     if (m_haveBackgroundParser)
         stopBackgroundParser();
@@ skipping 14 matching lines @@
 void HTMLDocumentParser::trace(Visitor* visitor)
 {
     visitor->trace(m_treeBuilder);
     visitor->trace(m_xssAuditorDelegate);
     visitor->trace(m_scriptRunner);
     visitor->trace(m_preloader);
     ScriptableDocumentParser::trace(visitor);
     HTMLScriptRunnerHost::trace(visitor);
 }
 
-void HTMLDocumentParser::pinToMainThread()
-{
-    ASSERT(!m_haveBackgroundParser);
-    ASSERT(!m_isPinnedToMainThread);
-    m_isPinnedToMainThread = true;
-    if (!m_tokenizer) {
-        ASSERT(!m_token);
-        m_token = adoptPtr(new HTMLToken);
-        m_tokenizer = HTMLTokenizer::create(m_options);
-    }
-}
-
 void HTMLDocumentParser::detach()
 {
     if (m_haveBackgroundParser)
         stopBackgroundParser();
     DocumentParser::detach();
     if (m_scriptRunner)
         m_scriptRunner->detach();
     m_treeBuilder->detach();
     // FIXME: It seems wrong that we would have a preload scanner here.
     // Yet during fast/dom/HTMLScriptElement/script-load-events.html we do.
@@ skipping 70 matching lines @@
 }
 
 bool HTMLDocumentParser::isScheduledForResume() const
 {
     return m_parserScheduler && m_parserScheduler->isScheduledForResume();
 }
 
 // Used by HTMLParserScheduler
 void HTMLDocumentParser::resumeParsingAfterYield()
 {
-    ASSERT(!m_isPinnedToMainThread);
+    ASSERT(shouldUseThreading());
     ASSERT(m_haveBackgroundParser);
 
     // pumpPendingSpeculations can cause this parser to be detached from the Document,
     // but we need to ensure it isn't deleted yet.
     RefPtrWillBeRawPtr<HTMLDocumentParser> protect(this);
     pumpPendingSpeculations();
 }
 
 void HTMLDocumentParser::runScriptsForPausedTreeBuilder()
 {
@@ skipping 499 matching lines @@
 
     m_input.appendToEnd(source);
 
     if (inPumpSession()) {
         // We've gotten data off the network in a nested write.
         // We don't want to consume any more of the input stream now.  Do
         // not worry.  We'll consume this data in a less-nested write().
         return;
     }
 
-    // A couple pinToMainThread() callers require synchronous parsing, but can't
-    // easily use the insert() method, so we hack append() for them to be synchronous.
-    // javascript: url handling is one such caller.
-    // FIXME: This is gross, and we should separate the concept of synchronous parsing
-    // from insert() so that only document.write() uses insert.

[kbalazs, 2014/12/05 23:42:04]

This comment was pretty confusing also. No one else should use insert other than
document.write. I don't think there is any problem with append being synchronous
(i.e. pumping immediately) because that is what callers expect and that's what
other DocumentParser subclasses do also.

-    ASSERT(m_isPinnedToMainThread);
     pumpTokenizerIfPossible();
-
     endIfDelayed();
 }
 
 void HTMLDocumentParser::end()
 {
     ASSERT(!isDetached());
     ASSERT(!isScheduledForResume());
 
     if (m_haveBackgroundParser)
         stopBackgroundParser();
@@ skipping 183 matching lines @@
     // but we need to ensure it isn't deleted yet.
     RefPtrWillBeRawPtr<HTMLDocumentParser> protect(this);
     m_scriptRunner->executeScriptsWaitingForResources();
     if (!isWaitingForScripts())
         resumeParsingAfterScriptExecution();
 }
 
 void HTMLDocumentParser::parseDocumentFragment(const String& source, DocumentFragment* fragment, Element* contextElement, ParserContentPolicy parserContentPolicy)
 {
     RefPtrWillBeRawPtr<HTMLDocumentParser> parser = HTMLDocumentParser::create(fragment, contextElement, parserContentPolicy);
     parser->insert(source); // Use insert() so that the parser will not yield.

[kouhei (in TOK), 2014/12/08 01:35:27]

should we change this to append?

     parser->finish();
     ASSERT(!parser->processingData()); // Make sure we're done. <rdar://problem/3963151>
     parser->detach(); // Allows ~DocumentParser to assert it was detached before destruction.
 }
 
 void HTMLDocumentParser::suspendScheduledTasks()
 {
     ASSERT(!m_tasksWereSuspended);
     m_tasksWereSuspended = true;
     if (m_parserScheduler)
@@ skipping 43 matching lines @@
 void HTMLDocumentParser::setDecoder(PassOwnPtr<TextResourceDecoder> decoder)
 {
     ASSERT(decoder);
     DecodedDataDocumentParser::setDecoder(decoder);
 
     if (m_haveBackgroundParser)
         HTMLParserThread::shared()->postTask(bind(&BackgroundHTMLParser::setDecoder, m_backgroundParser, takeDecoder()));
 }
 
 }