Source/core/workers/WorkerThread.h

/*
 * 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
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, 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 APPLE COMPUTER, 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.
 *
 */

#ifndef WorkerThread_h
#define WorkerThread_h

#include "core/dom/ExecutionContextTask.h"
#include "core/frame/csp/ContentSecurityPolicy.h"
#include "core/workers/WorkerGlobalScope.h"
#include "platform/SharedTimer.h"
#include "platform/heap/glue/MessageLoopInterruptor.h"
#include "platform/heap/glue/PendingGCRunner.h"
#include "platform/weborigin/SecurityOrigin.h"
#include "public/platform/WebThread.h"
#include "wtf/Forward.h"
#include "wtf/MessageQueue.h"
#include "wtf/OwnPtr.h"
#include "wtf/PassRefPtr.h"
#include "wtf/RefCounted.h"

namespace blink {
class WebWaitableEvent;
}

namespace blink {

    class KURL;
    class WorkerGlobalScope;
    class WorkerInspectorController;
    class WorkerLoaderProxy;
    class WorkerReportingProxy;
    class WorkerSharedTimer;
    class WorkerThreadShutdownFinishTask;
    class WorkerThreadStartupData;
    class WorkerThreadTask;

    enum WorkerThreadStartMode { DontPauseWorkerGlobalScopeOnStart, PauseWorkerGlobalScopeOnStart };


    class WorkerThread : public RefCounted<WorkerThread> {
    public:
        virtual ~WorkerThread();

        virtual void start();
        virtual void stop();

        // Can be used to wait for this worker thread to shut down.
        // (This is signalled on the main thread, so it's assumed to be waited on the worker context thread)
        blink::WebWaitableEvent* shutdownEvent() { return m_shutdownEvent.get(); }

        bool isCurrentThread() const;
        WorkerLoaderProxy& workerLoaderProxy() const { return m_workerLoaderProxy; }
        WorkerReportingProxy& workerReportingProxy() const { return m_workerReportingProxy; }

        void postTask(PassOwnPtr<ExecutionContextTask>);
        void postDebuggerTask(PassOwnPtr<ExecutionContextTask>);

        enum WaitMode { WaitForMessage, DontWaitForMessage };
        MessageQueueWaitResult runDebuggerTask(WaitMode = WaitForMessage);

        // These methods should be called if the holder of the thread is
        // going to call runDebuggerTask in a loop.
        void willEnterNestedLoop();
        void didLeaveNestedLoop();

        WorkerGlobalScope* workerGlobalScope() const { return m_workerGlobalScope.get(); }
        bool terminated() const { return m_terminated; }

        // Number of active worker threads.
        static unsigned workerThreadCount();

        void interruptAndDispatchInspectorCommands();
        void setWorkerInspectorController(WorkerInspectorController*);

    protected:
        WorkerThread(WorkerLoaderProxy&, WorkerReportingProxy&, PassOwnPtrWillBeRawPtr<WorkerThreadStartupData>);

        // Factory method for creating a new worker context for the thread.
        virtual PassRefPtrWillBeRawPtr<WorkerGlobalScope> createWorkerGlobalScope(PassOwnPtrWillBeRawPtr<WorkerThreadStartupData>) = 0;

        virtual void postInitialize() { }

    private:
        friend class WorkerSharedTimer;
        friend class WorkerThreadShutdownFinishTask;

        void initialize();
        void cleanup();
        void idleHandler();
        void postDelayedTask(PassOwnPtr<ExecutionContextTask>, long long delayMs);

        bool m_terminated;
        OwnPtr<WorkerSharedTimer> m_sharedTimer;
        MessageQueue<WorkerThreadTask> m_debuggerMessageQueue;
        OwnPtr<PendingGCRunner> m_pendingGCRunner;
        OwnPtr<WebThread::TaskObserver> m_microtaskRunner;
        OwnPtr<MessageLoopInterruptor> m_messageLoopInterruptor;

        WorkerLoaderProxy& m_workerLoaderProxy;
        WorkerReportingProxy& m_workerReportingProxy;

        RefPtrWillBePersistent<WorkerInspectorController> m_workerInspectorController;
        Mutex m_workerInspectorControllerMutex;

        Mutex m_threadCreationMutex;
        RefPtrWillBePersistent<WorkerGlobalScope> m_workerGlobalScope;
        OwnPtrWillBePersistent<WorkerThreadStartupData> m_startupData;

        // Used to signal thread shutdown.
        OwnPtr<blink::WebWaitableEvent> m_shutdownEvent;

        // FIXME: This has to be last because of crbug.com/401397 - the
        // WorkerThread might get deleted before it had a chance to properly
        // shut down. By deleting the WebThread first, we can guarantee that
        // no pending tasks on the thread might want to access any of the other
        // members during the WorkerThread's destruction.
        OwnPtr<blink::WebThread> m_thread;
    };

} // namespace blink

#endif // WorkerThread_h