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      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 are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include "config.h"
     32 #include "ActiveDOMCallback.h"
     33 
     34 #include "ActiveDOMObject.h"
     35 #include "ScriptExecutionContext.h"
     36 #include <wtf/PassOwnPtr.h>
     37 #include <wtf/ThreadingPrimitives.h>
     38 
     39 namespace WebCore {
     40 
     41 static void destroyOnContextThread(PassOwnPtr<ActiveDOMObjectCallbackImpl>);
     42 
     43 class DestroyOnContextThreadTask : public ScriptExecutionContext::Task {
     44 public:
     45     static PassOwnPtr<DestroyOnContextThreadTask> create(PassOwnPtr<ActiveDOMObjectCallbackImpl> impl)
     46     {
     47         return adoptPtr(new DestroyOnContextThreadTask(impl));
     48     }
     49 
     50     virtual void performTask(ScriptExecutionContext*)
     51     {
     52         destroyOnContextThread(m_impl.release());
     53     }
     54 
     55 private:
     56     DestroyOnContextThreadTask(PassOwnPtr<ActiveDOMObjectCallbackImpl> impl)
     57         : m_impl(impl)
     58     {
     59     }
     60 
     61     OwnPtr<ActiveDOMObjectCallbackImpl> m_impl;
     62 };
     63 
     64 class ActiveDOMObjectCallbackImpl : public ActiveDOMObject {
     65 public:
     66     ActiveDOMObjectCallbackImpl(ScriptExecutionContext* context)
     67         : ActiveDOMObject(context, this)
     68         , m_suspended(false)
     69         , m_stopped(false)
     70     {
     71     }
     72 
     73     virtual void contextDestroyed()
     74     {
     75         MutexLocker locker(m_mutex);
     76         ActiveDOMObject::contextDestroyed();
     77     }
     78     virtual bool canSuspend() const { return false; }
     79     virtual void suspend(ReasonForSuspension)
     80     {
     81         MutexLocker locker(m_mutex);
     82         m_suspended = true;
     83     }
     84     virtual void resume()
     85     {
     86         MutexLocker locker(m_mutex);
     87         m_suspended = false;
     88     }
     89     virtual void stop()
     90     {
     91         MutexLocker locker(m_mutex);
     92         m_stopped = true;
     93     }
     94     bool canInvokeCallback()
     95     {
     96         MutexLocker locker(m_mutex);
     97         return (!m_suspended && !m_stopped);
     98     }
     99     ScriptExecutionContext* scriptExecutionContext()
    100     {
    101         MutexLocker locker(m_mutex);
    102         return ActiveDOMObject::scriptExecutionContext();
    103     }
    104     Mutex& mutex() { return m_mutex; }
    105 
    106 private:
    107     Mutex m_mutex;
    108     bool m_suspended;
    109     bool m_stopped;
    110 };
    111 
    112 static void destroyOnContextThread(PassOwnPtr<ActiveDOMObjectCallbackImpl> impl)
    113 {
    114     OwnPtr<ActiveDOMObjectCallbackImpl> implOwnPtr = impl;
    115 
    116     ScriptExecutionContext* context = implOwnPtr->scriptExecutionContext();
    117     MutexLocker locker(implOwnPtr->mutex());
    118     if (context && !context->isContextThread())
    119         context->postTask(DestroyOnContextThreadTask::create(implOwnPtr.release()));
    120 }
    121 
    122 ActiveDOMCallback::ActiveDOMCallback(ScriptExecutionContext* context)
    123     : m_impl(new ActiveDOMObjectCallbackImpl(context))
    124 {
    125 }
    126 
    127 ActiveDOMCallback::~ActiveDOMCallback()
    128 {
    129     destroyOnContextThread(m_impl.release());
    130 }
    131 
    132 bool ActiveDOMCallback::canInvokeCallback() const
    133 {
    134     return m_impl->canInvokeCallback();
    135 }
    136 
    137 ScriptExecutionContext* ActiveDOMCallback::scriptExecutionContext() const
    138 {
    139     return m_impl->scriptExecutionContext();
    140 }
    141 
    142 } // namespace WebCore
    143