third_party/WebKit/Source/core/dom/ScriptRunner.cpp

   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/dom/ScriptRunner.h"
  28
  29 #include "core/dom/Document.h"
  30 #include "core/dom/Element.h"
  31 #include "core/dom/ScriptLoader.h"
  32 #include "platform/heap/Handle.h"
  33 #include "public/platform/Platform.h"
  34 #include "public/platform/WebScheduler.h"
  35 #include "public/platform/WebThread.h"
  36 #include "wtf/Functional.h"
  37
  38 // This bit of magic is needed by oilpan to prevent the ScriptRunner from leaking.
  39 namespace WTF {
  40 template<>
  41 struct ParamStorageTraits<blink::ScriptRunner*> : public PointerParamStorageTraits<blink::ScriptRunner*, false> {
  42 };
  43 }
  44
  45 namespace blink {
  46
  47
  48 ScriptRunner::ScriptRunner(Document* document)
  49     : m_document(document)
  50     , m_executeScriptsTaskFactory(WTF::bind(&ScriptRunner::executeScripts, this))
  51 {
  52     ASSERT(document);
  53 #if ENABLE(LAZY_SWEEPING) && defined(ADDRESS_SANITIZER)
  54     m_executeScriptsTaskFactory.setUnpoisonBeforeUpdate();
  55 #endif
  56 }
  57
  58 ScriptRunner::~ScriptRunner()
  59 {
  60 #if !ENABLE(OILPAN)
  61     // Make sure that ScriptLoaders don't keep their PendingScripts alive.
  62     for (ScriptLoader* scriptLoader : m_scriptsToExecuteInOrder)
  63         scriptLoader->detach();
  64     for (ScriptLoader* scriptLoader : m_scriptsToExecuteSoon)
  65         scriptLoader->detach();
  66     for (ScriptLoader* scriptLoader : m_pendingAsyncScripts)
  67         scriptLoader->detach();
  68 #endif
  69 }
  70
  71 void ScriptRunner::addPendingAsyncScript(ScriptLoader* scriptLoader)
  72 {
  73     m_document->incrementLoadEventDelayCount();
  74     m_pendingAsyncScripts.add(scriptLoader);
  75 }
  76
  77 void ScriptRunner::queueScriptForExecution(ScriptLoader* scriptLoader, ExecutionType executionType)
  78 {
  79     ASSERT(scriptLoader);
  80
  81     switch (executionType) {
  82     case ASYNC_EXECUTION:
  83         addPendingAsyncScript(scriptLoader);
  84         break;
  85
  86     case IN_ORDER_EXECUTION:
  87         m_document->incrementLoadEventDelayCount();
  88         m_scriptsToExecuteInOrder.append(scriptLoader);
  89         break;
  90     }
  91 }
  92
  93 void ScriptRunner::suspend()
  94 {
  95     m_executeScriptsTaskFactory.cancel();
  96 }
  97
  98 void ScriptRunner::resume()
  99 {
 100     if (hasPendingScripts())
 101         postTaskIfOneIsNotAlreadyInFlight();
 102 }
 103
 104 void ScriptRunner::notifyScriptReady(ScriptLoader* scriptLoader, ExecutionType executionType)
 105 {
 106     RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(scriptLoader);
 107     switch (executionType) {
 108     case ASYNC_EXECUTION:
 109         // RELEASE_ASSERT makes us crash in a controlled way in error cases
 110         // where the ScriptLoader is associated with the wrong ScriptRunner
 111         // (otherwise we'd cause a use-after-free in ~ScriptRunner when it tries
 112         // to detach).
 113         RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(m_pendingAsyncScripts.contains(scriptLoader));
 114         m_scriptsToExecuteSoon.append(scriptLoader);
 115         m_pendingAsyncScripts.remove(scriptLoader);
 116         break;
 117
 118     case IN_ORDER_EXECUTION:
 119         RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(!m_scriptsToExecuteInOrder.isEmpty());
 120         break;
 121     }
 122     postTaskIfOneIsNotAlreadyInFlight();
 123 }
 124
 125 void ScriptRunner::notifyScriptLoadError(ScriptLoader* scriptLoader, ExecutionType executionType)
 126 {
 127     switch (executionType) {
 128     case ASYNC_EXECUTION:
 129         // RELEASE_ASSERT makes us crash in a controlled way in error cases
 130         // where the ScriptLoader is associated with the wrong ScriptRunner
 131         // (otherwise we'd cause a use-after-free in ~ScriptRunner when it tries
 132         // to detach).
 133         RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(m_pendingAsyncScripts.contains(scriptLoader));
 134         m_pendingAsyncScripts.remove(scriptLoader);
 135         break;
 136
 137     case IN_ORDER_EXECUTION:
 138         RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(!m_scriptsToExecuteInOrder.isEmpty());
 139         // Remove; script failed to load and error event has been dispatched.
 140         ScriptLoader* script = m_scriptsToExecuteInOrder.takeFirst();
 141         ASSERT_UNUSED(script, script == scriptLoader);
 142         break;
 143     }
 144     scriptLoader->detach();
 145     m_document->decrementLoadEventDelayCount();
 146 }
 147
 148 void ScriptRunner::movePendingAsyncScript(Document& oldDocument, Document& newDocument, ScriptLoader* scriptLoader)
 149 {
 150     RefPtrWillBeRawPtr<Document> newContextDocument = newDocument.contextDocument().get();
 151     if (!newContextDocument) {
 152         // Document's contextDocument() method will return no Document if the
 153         // following conditions both hold:
 154         //
 155         //   - The Document wasn't created with an explicit context document
 156         //     and that document is otherwise kept alive.
 157         //   - The Document itself is detached from its frame.
 158         //
 159         // The script element's loader is in that case moved to document() and
 160         // its script runner, which is the non-null Document that contextDocument()
 161         // would return if not detached.
 162         ASSERT(!newDocument.frame());
 163         newContextDocument = &newDocument;
 164     }
 165     RefPtrWillBeRawPtr<Document> oldContextDocument = oldDocument.contextDocument().get();
 166     if (!oldContextDocument) {
 167         ASSERT(!oldDocument.frame());
 168         oldContextDocument = &oldDocument;
 169     }
 170     if (oldContextDocument != newContextDocument)
 171         oldContextDocument->scriptRunner()->movePendingAsyncScript(newContextDocument->scriptRunner(), scriptLoader);
 172 }
 173
 174 void ScriptRunner::movePendingAsyncScript(ScriptRunner* newRunner, ScriptLoader* scriptLoader)
 175 {
 176     if (m_pendingAsyncScripts.contains(scriptLoader)) {
 177         newRunner->addPendingAsyncScript(scriptLoader);
 178         m_pendingAsyncScripts.remove(scriptLoader);
 179         m_document->decrementLoadEventDelayCount();
 180     }
 181 }
 182
 183 void ScriptRunner::executeScripts()
 184 {
 185     RefPtrWillBeRawPtr<Document> protect(m_document.get());
 186
 187     WillBeHeapDeque<RawPtrWillBeMember<ScriptLoader>> scriptLoaders;
 188     scriptLoaders.swap(m_scriptsToExecuteSoon);
 189
 190     WillBeHeapHashSet<RawPtrWillBeMember<ScriptLoader>> inorderSet;
 191     while (!m_scriptsToExecuteInOrder.isEmpty() && m_scriptsToExecuteInOrder.first()->isReady()) {
 192         ScriptLoader* script = m_scriptsToExecuteInOrder.takeFirst();
 193         inorderSet.add(script);
 194         scriptLoaders.append(script);
 195     }
 196
 197     while (!scriptLoaders.isEmpty()) {
 198         scriptLoaders.takeFirst()->execute();
 199         m_document->decrementLoadEventDelayCount();
 200
 201         if (yieldForHighPriorityWork())
 202             break;
 203     }
 204
 205     // If we have to yield, we must re-enqueue any scriptLoaders back onto the front of
 206     // m_scriptsToExecuteInOrder or m_scriptsToExecuteSoon depending on where the script
 207     // came from.
 208     // NOTE a yield followed by a notifyScriptReady(... ASYNC_EXECUTION) will result in that script executing
 209     // before any pre-existing ScriptsToExecuteInOrder.
 210     while (!scriptLoaders.isEmpty()) {
 211         ScriptLoader* script = scriptLoaders.takeLast();
 212         if (inorderSet.contains(script))
 213             m_scriptsToExecuteInOrder.prepend(script);
 214         else
 215             m_scriptsToExecuteSoon.prepend(script);
 216     }
 217 }
 218
 219 bool ScriptRunner::yieldForHighPriorityWork()
 220 {
 221     if (!Platform::current()->currentThread()->scheduler()->shouldYieldForHighPriorityWork())
 222         return false;
 223
 224     postTaskIfOneIsNotAlreadyInFlight();
 225     return true;
 226 }
 227
 228 void ScriptRunner::postTaskIfOneIsNotAlreadyInFlight()
 229 {
 230     if (m_executeScriptsTaskFactory.isPending())
 231         return;
 232
 233     // FIXME: Rename task() so that it's obvious it cancels any pending task.
 234     Platform::current()->currentThread()->scheduler()->postLoadingTask(FROM_HERE, m_executeScriptsTaskFactory.cancelAndCreate());
 235 }
 236
 237 DEFINE_TRACE(ScriptRunner)
 238 {
 239 #if ENABLE(OILPAN)
 240     visitor->trace(m_document);
 241     visitor->trace(m_scriptsToExecuteInOrder);
 242     visitor->trace(m_scriptsToExecuteSoon);
 243     visitor->trace(m_pendingAsyncScripts);
 244 #endif
 245 }
 246
 247 }