1 /* 2 * Copyright (C) 2010 Google, Inc. All Rights Reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include "config.h" 27 #include "core/html/parser/HTMLParserScheduler.h" 28 29 #include "core/dom/Document.h" 30 #include "core/html/parser/HTMLDocumentParser.h" 31 #include "core/frame/FrameView.h" 32 33 namespace blink { 34 35 // parserChunkSize is used to define how many tokens the parser will 36 // process before checking against parserTimeLimit and possibly yielding. 37 // This is a performance optimization to prevent checking after every token. 38 const int HTMLParserScheduler::parserChunkSize = 4096; 39 40 // parserTimeLimit is the seconds the parser will run in one write() call 41 // before yielding. Inline <script> execution can cause it to exceed the limit. 42 const double HTMLParserScheduler::parserTimeLimit = 0.2; 43 44 ActiveParserSession::ActiveParserSession(Document* document) 45 : m_document(document) 46 { 47 if (!m_document) 48 return; 49 m_document->incrementActiveParserCount(); 50 } 51 52 ActiveParserSession::~ActiveParserSession() 53 { 54 if (!m_document) 55 return; 56 m_document->decrementActiveParserCount(); 57 } 58 59 PumpSession::PumpSession(unsigned& nestingLevel, Document* document) 60 : NestingLevelIncrementer(nestingLevel) 61 , ActiveParserSession(document) 62 // Setting processedTokens to INT_MAX causes us to check for yields 63 // after any token during any parse where yielding is allowed. 64 // At that time we'll initialize startTime. 65 , processedTokens(INT_MAX) 66 , startTime(0) 67 , needsYield(false) 68 , didSeeScript(false) 69 { 70 } 71 72 PumpSession::~PumpSession() 73 { 74 } 75 76 HTMLParserScheduler::HTMLParserScheduler(HTMLDocumentParser* parser) 77 : m_parser(parser) 78 , m_continueNextChunkTimer(this, &HTMLParserScheduler::continueNextChunkTimerFired) 79 , m_isSuspendedWithActiveTimer(false) 80 { 81 } 82 83 HTMLParserScheduler::~HTMLParserScheduler() 84 { 85 m_continueNextChunkTimer.stop(); 86 } 87 88 void HTMLParserScheduler::continueNextChunkTimerFired(Timer<HTMLParserScheduler>* timer) 89 { 90 ASSERT_UNUSED(timer, timer == &m_continueNextChunkTimer); 91 m_parser->resumeParsingAfterYield(); 92 } 93 94 void HTMLParserScheduler::scheduleForResume() 95 { 96 m_continueNextChunkTimer.startOneShot(0, FROM_HERE); 97 } 98 99 void HTMLParserScheduler::suspend() 100 { 101 ASSERT(!m_isSuspendedWithActiveTimer); 102 if (!m_continueNextChunkTimer.isActive()) 103 return; 104 m_isSuspendedWithActiveTimer = true; 105 m_continueNextChunkTimer.stop(); 106 } 107 108 void HTMLParserScheduler::resume() 109 { 110 ASSERT(!m_continueNextChunkTimer.isActive()); 111 if (!m_isSuspendedWithActiveTimer) 112 return; 113 m_isSuspendedWithActiveTimer = false; 114 m_continueNextChunkTimer.startOneShot(0, FROM_HERE); 115 } 116 117 } 118