Move workers to Chromium threading

Source/core/workers/WorkerThread.cpp

 /*
  * Copyright (C) 2008 Apple 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 15 matching lines @@
 
 #include "config.h"
 
 #include "core/workers/WorkerThread.h"
 
 #include "bindings/v8/ScriptSourceCode.h"
 #include "bindings/v8/ScriptValue.h"
 #include "core/inspector/InspectorInstrumentation.h"
 #include "core/platform/KURL.h"
 #include "core/platform/ThreadGlobalData.h"
+#include "core/platform/Task.h"
 #include "core/workers/DedicatedWorkerContext.h"
 #include "modules/webdatabase/DatabaseManager.h"
 #include "modules/webdatabase/DatabaseTask.h"
 
 #include <utility>
 #include <wtf/Noncopyable.h>
 #include <wtf/text/WTFString.h>
 
 #include <public/Platform.h>
 #include <public/WebWorkerRunLoop.h>
@@ skipping 50 matching lines @@
     if (!settings)
         return;
 
     m_groupSettings = GroupSettings::create();
     m_groupSettings->setLocalStorageQuotaBytes(settings->localStorageQuotaBytes());
     m_groupSettings->setIndexedDBQuotaBytes(settings->indexedDBQuotaBytes());
     m_groupSettings->setIndexedDBDatabasePath(settings->indexedDBDatabasePath().isolatedCopy());
 }
 
 WorkerThread::WorkerThread(const KURL& scriptURL, const String& userAgent, const GroupSettings* settings, const String& sourceCode, WorkerLoaderProxy& workerLoaderProxy, WorkerReportingProxy& workerReportingProxy, WorkerThreadStartMode startMode, const String& contentSecurityPolicy, ContentSecurityPolicy::HeaderType contentSecurityPolicyType, const SecurityOrigin* topOrigin)
-    : m_threadID(0)
-    , m_workerLoaderProxy(workerLoaderProxy)
+    : m_workerLoaderProxy(workerLoaderProxy)
     , m_workerReportingProxy(workerReportingProxy)
     , m_startupData(WorkerThreadStartupData::create(scriptURL, userAgent, settings, sourceCode, startMode, contentSecurityPolicy, contentSecurityPolicyType, topOrigin))
 #if ENABLE(NOTIFICATIONS) || ENABLE(LEGACY_NOTIFICATIONS)
     , m_notificationClient(0)
 #endif
 {
     MutexLocker lock(threadSetMutex());
     workerThreads().add(this);
 }
 
 WorkerThread::~WorkerThread()
 {
     MutexLocker lock(threadSetMutex());
     ASSERT(workerThreads().contains(this));
     workerThreads().remove(this);
 }
 
 bool WorkerThread::start()
 {
-    // Mutex protection is necessary to ensure that m_threadID is initialized when the thread starts.
+    // Mutex protection is necessary to ensure that m_thread is initialized when the thread starts.
     MutexLocker lock(m_threadCreationMutex);
 
-    if (m_threadID)
+    if (m_thread)
         return true;
 
-    m_threadID = createThread(WorkerThread::workerThreadStart, this, "WebCore: Worker");
-
-    return m_threadID;
-}
-
-void WorkerThread::workerThreadStart(void* thread)
-{
-    static_cast<WorkerThread*>(thread)->workerThread();
+    m_thread = adoptPtr(WebKit::Platform::current()->createThread("WebCore: Worker"));
+    m_thread->postTask(new Task(bind(&WorkerThread::workerThread, this)));
+    return true;
 }
 
 void WorkerThread::workerThread()
 {
     {
         MutexLocker lock(m_threadCreationMutex);
         m_workerContext = createWorkerContext(m_startupData->m_scriptURL, m_startupData->m_userAgent, m_startupData->m_groupSettings.release(), m_startupData->m_contentSecurityPolicy, m_startupData->m_contentSecurityPolicyType, m_startupData->m_topOrigin.release());
 
         if (m_runLoop.terminated()) {
             // The worker was terminated before the thread had a chance to run. Since the context didn't exist yet,
             // forbidExecution() couldn't be called from stop().
            m_workerContext->script()->forbidExecution();
         }
     }
     // The corresponding call to didStopWorkerRunLoop is in
     // ~WorkerScriptController.
     WebKit::Platform::current()->didStartWorkerRunLoop(WebKit::WebWorkerRunLoop(&m_runLoop));
 
     WorkerScriptController* script = m_workerContext->script();
     InspectorInstrumentation::willEvaluateWorkerScript(workerContext(), m_startupData->m_startMode);
     script->evaluate(ScriptSourceCode(m_startupData->m_sourceCode, m_startupData->m_scriptURL));
     // Free the startup data to cause its member variable deref's happen on the worker's thread (since
     // all ref/derefs of these objects are happening on the thread at this point). Note that
     // WorkerThread::~WorkerThread happens on a different thread where it was created.
     m_startupData.clear();
 
     runEventLoop();
 
-    ThreadIdentifier threadID = m_threadID;
-
     ASSERT(m_workerContext->hasOneRef());
 
     // The below assignment will destroy the context, which will in turn notify messaging proxy.
     // We cannot let any objects survive past thread exit, because no other thread will run GC or otherwise destroy them.
     m_workerContext = 0;
 
     // Clean up WebCore::ThreadGlobalData before WTF::WTFThreadData goes away!
     threadGlobalData().destroy();
-
-    // The thread object may be already destroyed from notification now, don't try to access "this".
-    detachThread(threadID);

[jamesr, 2013/05/20 20:56:29]

hmm, should we make an explicit effort to kill the WebThread here?  When is the
WorkerThread object destructed?  We want to make sure to tear down all WebThread
objects before WebKit::shutdown() is called

[abarth-chromium, 2013/05/20 21:00:36]

Yes, I tried for a while having this code release() the WebThread into a local
variable, which ensures that it gets deleted.  The problem is that code below
"m_workerContext = 0" wants to access m_thread.
It's destructed below "m_workerContext = 0".
Yes, definitely.

 }
 
 void WorkerThread::runEventLoop()
 {
     // Does not return until terminated.
     m_runLoop.run(m_workerContext.get());
 }
 
 class WorkerThreadShutdownFinishTask : public ScriptExecutionContext::Task {
 public:
@@ skipping 59 matching lines @@
     if (m_workerContext) {
         m_workerContext->script()->scheduleExecutionTermination();
 
         DatabaseManager::manager().interruptAllDatabasesForContext(m_workerContext.get());
         m_runLoop.postTaskAndTerminate(WorkerThreadShutdownStartTask::create());
         return;
     }
     m_runLoop.terminate();
 }
 
+bool WorkerThread::isCurrentThread() const
+{
+    return m_thread->isCurrentThread();
+}
+
 class ReleaseFastMallocFreeMemoryTask : public ScriptExecutionContext::Task {
     virtual void performTask(ScriptExecutionContext*) OVERRIDE { WTF::releaseFastMallocFreeMemory(); }
 };
 
 void WorkerThread::releaseFastMallocFreeMemoryInAllThreads()
 {
     MutexLocker lock(threadSetMutex());
     HashSet<WorkerThread*>& threads = workerThreads();
     HashSet<WorkerThread*>::iterator end = threads.end();
     for (HashSet<WorkerThread*>::iterator it = threads.begin(); it != end; ++it)
         (*it)->runLoop().postTask(adoptPtr(new ReleaseFastMallocFreeMemoryTask));
 }
 
 } // namespace WebCore